Tuesday, December 30, 2008

Self Control and Belief in God

December 30, 2008
For Good Self-Control, Try Getting Religious About It


...In a new paper [in the upcoming issue of the Psychological Bulletin], Miami psychologists surveyed the literature to test the proposition that religion gives people internal strength.

“We simply asked if there was good evidence that people who are more religious have more self-control,” Dr. McCullough. “For a long time it wasn’t cool for social scientists to study religion, but some researchers were quietly chugging along for decades. When you add it all up, it turns out there are remarkably consistent findings that religiosity correlates with higher self-control.”

As early as the 1920s, researchers found that students who spent more time in Sunday school did better at laboratory tests measuring their self-discipline. Subsequent studies showed that religiously devout children were rated relatively low in impulsiveness by both parents and teachers, and that religiosity repeatedly correlated with higher self-control among adults. Devout people were found to be more likely than others to wear seat belts, go to the dentist and take vitamins.
But which came first, the religious devotion or the self-control? It takes self-discipline to sit through Sunday school or services at a temple or mosque, so people who start out with low self-control are presumably less likely to keep attending. But even after taking that self-selection bias into account, Dr. McCullough said there is still reason to believe that religion has a strong influence.

“Brain-scan studies have shown that when people pray or meditate, there’s a lot of activity in two parts of brain that are important for self-regulation and control of attention and emotion,” he said. “The rituals that religions have been encouraging for thousands of years seem to be a kind of anaerobic workout for self-control.”

In a study published by the University of Maryland in 2003, students who were subliminally exposed to religious words (like God, prayer or bible) were slower to recognize words associated with temptations (like drugs or premarital sex). Conversely, when they were primed with the temptation words, they were quicker to recognize the religious words.

“It looks as if people come to associate religion with tamping down these temptations,” Dr. McCullough said. “When temptations cross their minds in daily life, they quickly use religion to dispel them from their minds.”

In one personality study, strongly religious people were compared with people who subscribed to more general spiritual notions, like the idea that their lives were “directed by a spiritual force greater than any human being” or that they felt “a spiritual connection to other people.” The religious people scored relatively high in conscientiousness and self-control, whereas the spiritual people tended to score relatively low.

“Thinking about the oneness of humanity and the unity of nature doesn’t seem to be related to self-control,” Dr. McCullough said. “The self-control effect seems to come from being engaged in religious institutions and behaviors.”....

Religious people, he said, are self-controlled not simply because they fear God’s wrath, but because they’ve absorbed the ideals of their religion into their own system of values, and have thereby given their personal goals an aura of sacredness. He suggested that nonbelievers try a secular version of that strategy.

“People can have sacred values that aren’t religious values,” he said. “Self-reliance might be a sacred value to you that’s relevant to saving money. Concern for others might be a sacred value that’s relevant to taking time to do volunteer work. You can spend time thinking about what values are sacred to you and making New Year’s resolutions that are consistent with them.”

Of course, it requires some self-control to carry out that exercise — and maybe more effort than it takes to go to church.

“Sacred values come prefabricated for religious believers,” Dr. McCullough said. “The belief that God has preferences for how you behave and the goals you set for yourself has to be the granddaddy of all psychological devices for encouraging people to follow through with their goals.
That may help to explain why belief in God has been so persistent through the ages.”

Wednesday, October 22, 2008

Why Darwin Would Have Loved Botox

By Karl Zimmer
Discover Magazine


...When humans mimic others’ faces, in other words, we don’t just go through the motions. We also go through the emotions.

Recently Bernhard Haslinger at the Technical University of Munich realized that he could test the facial feedback theory in a new way. He could temporarily paralyze facial muscles and then scan people’s brains as they tried to make faces. To block facial feedback, Haslinger used Dysport, a Botox-like drug available in Europe.

Botox and Dysport are brand names of a toxin made by the spore-forming bacterium Clostridium botulinum. Botulinum docks on the surface of neurons, blocking the release of a transmitter called acetylcholine. In small amounts botulinum can be fatal. In far, far smaller amounts, it can simply paralyze a small patch of muscles for a few weeks. Haslinger has used Dysport in people with movement disorders like dystonia to help reduce unwanted muscle movement. But Botox and Dysport are best known as treatments to mask aging. Injections into the muscles that make frowns can slow the growth of lines around the eyebrows.

For his brain experiment, Haslinger and his colleagues gave 19 women Dysport injections. Two weeks later the scientists scanned their brains as they showed the women a series of angry or sad faces and asked them either to imitate or just to observe the expressions. Haslinger then ran the same experiment on 19 women without Dysport and compared the two sets of scans.

When the women made sad faces, the same brain regions became active in both those with Dysport and those without. But making angry faces triggered different patterns. In the Dysport-free women, a region known as the amygdala—a key brain region for processing emotions—became active. In the women with Dysport, who could not use their frown muscles, the amygdala was quieter. Haslinger also found another change, in the connections between the amygdala and the brain stem, where signals can trigger many of the feelings that go along with emotions: Dysport made that connection weaker.

Of course neuroscience labs are not the only place where people get shots of Dysport or Botox. According to the American Society of Plastic Surgeons, in the United States doctors administer millions of injections of Botox each year, many of them to people’s faces. Haslinger’s research suggests that this is part of a massive, unplanned experiment.

In June 2008 in the Journal of the American Academy of Dermatology, a team of cosmetic surgeons suggested this experiment is making all of us happier. People with Botox may be less vulnerable to the angry emotions of other people because they themselves can’t make angry or unhappy faces as easily. And because people with Botox can’t spread bad feelings to others via their expressions, people without Botox may be happier too. The surgeons grant that this is just speculation for now. Nevertheless, they declare that “we are left with the tantalizing possibility that cosmetic procedures may have beneficial effects that are more than skin deep.”

Maybe. But for all the Botox youthfulness plastic surgeons may want to think about, neuroscience raises a darker possibility. Making faces helps us understand how other people are feeling. By altering our faces we’re tampering with the ancient lines of communication between face and brain that may change our minds in ways we don’t yet understand.

Sunday, October 12, 2008

Risk and reward compete in brain

Imaging study reveals battle between lure of reward and fear of failure.

That familiar pull between the promise of victory and the dread of defeat – whether in money, love or sport – is rooted in the brain's architecture, according to a new imaging study.

Neuroscientists at the USC Brain and Creativity Institute have identified distinct brain regions with competing responses to risk.

Both regions are located in the prefrontal cortex, an area behind the forehead involved in analysis and planning.

By giving volunteers a task that measures risk tolerance and observing their reactions with functional magnetic resonance imaging (fMRI), the researchers found that activity in one region identified risk-averse volunteers, while activity in a different region was greater in those with an appetite for risk.

The study appeared online Oct. 8 in the journal Cerebral Cortex.

"We can see risk as a battle between two forces," said Antoine Bechara, professor of psychology at USC. "There is always a lure of reward. There's always a fear of failure. These are the two forces that are always battling each other."

In his previous research, Bechara had used the same task to measure risk tolerance in brain-damaged patients. He and other researchers showed that the prefrontal cortex is critical for proper risk assessment.

But because brain lesions differ in every patient and affect multiple areas, lesion-based studies usually cannot pinpoint the role of smaller brain regions.

So Bechara's group at the institute decided to repeat the experiment with fMRI.

"We were interested in how normal people perform this task. What's going on in their brain?" asked first author Gui Xue, a postdoctoral research associate at the institute.

Bechara called his group's study the first to frame a person's risk profile in terms of the interaction between two brain regions.

Co-author Zhong-Lin Lu, professor of psychology at USC, said: "What this study has done is essentially localize two separate centers for the fear of risk and the lure of reward."

Contact: Carl Marziali
University of Southern California

Wednesday, September 10, 2008

As Barriers Disappear, Some Gender Gaps Widen

New York Times
September 9, 2008


When men and women take personality tests, some of the old Mars-Venus stereotypes keep reappearing. On average, women are more cooperative, nurturing, cautious and emotionally responsive. Men tend to be more competitive, assertive, reckless and emotionally flat. Clear differences appear in early childhood and never disappear.

What's not clear is the origin of these differences. Evolutionary psychologists contend that these are innate traits inherited from ancient hunters and gatherers. Another school of psychologists asserts that both sexes’ personalities have been shaped by traditional social roles, and that personality differences will shrink as women spend less time nurturing children and more time in jobs outside the home.

To test these hypotheses, a series of research teams have repeatedly analyzed personality tests taken by men and women in more than 60 countries around the world. For evolutionary psychologists, the bad news is that the size of the gender gap in personality varies among cultures. For social-role psychologists, the bad news is that the variation is going in the wrong direction. It looks as if personality differences between men and women are smaller in traditional cultures like India’s or Zimbabwe’s than in the Netherlands or the United States. A husband and a stay-at-home wife in a patriarchal Botswanan clan seem to be more alike than a working couple in Denmark or France. The more Venus and Mars have equal rights and similar jobs, the more their personalities seem to diverge.

These findings are so counterintuitive that some researchers have argued they must be because of cross-cultural problems with the personality tests. But after crunching new data from 40,000 men and women on six continents, David P. Schmitt and his colleagues conclude that the trends are real. Dr. Schmitt, a psychologist at Bradley University in Illinois and the director of the International Sexuality Description Project, suggests that as wealthy modern societies level external barriers between women and men, some ancient internal differences are being revived.

The biggest changes recorded by the researchers involve the personalities of men, not women. Men in traditional agricultural societies and poorer countries seem more cautious and anxious, less assertive and less competitive than men in the most progressive and rich countries of Europe and North America.

To explain these differences, Dr. Schmitt and his collaborators from Austria and Estonia point to the hardships of life in poorer countries. They note that in some other species, environmental stress tends to disproportionately affect the larger sex and mute costly secondary sexual characteristics (like male birds’ displays of plumage). And, they say, there are examples of stress muting biological sex differences in humans. For instance, the average disparity in height between men and women isn’t as pronounced in poor countries as it is in rich countries, because boys’ growth is disproportionately stunted by stresses like malnutrition and disease.

Personality is more complicated than height, of course, and Dr. Schmitt suggests it’s affected by not just the physical but also the social stresses in traditional agricultural societies. These villagers have had to adapt their personalities to rules, hierarchies and gender roles more constraining than those in modern Western countries — or in clans of hunter-gatherers.

“Humanity’s jaunt into monotheism, agriculturally based economies and the monopolization of power and resources by a few men was ‘unnatural’ in many ways,” Dr. Schmitt says, alluding to evidence that hunter-gatherers were relatively egalitarian. “In some ways modern progressive cultures are returning us psychologically to our hunter-gatherer roots,” he argues. “That means high sociopolitical gender equality over all, but with men and women expressing predisposed interests in different domains. Removing the stresses of traditional agricultural societies could allow men’s, and to a lesser extent women’s, more ‘natural’ personality traits to emerge.”

Some critics of this hypothesis question whether the international variations in personality have more to do with the way people in different cultures interpret questions on personality tests. (For more on this debate, go to www.nytimes.com/tierneylab.) The critics would like to see more direct measures of personality traits, and so would Dr. Schmitt. But he notes that there’s already an intriguing trend reported for one trait — competitiveness — based on direct measures of male and female runners.

Competitive running makes a good case study because, to mix athletic metaphors, it has offered a level playing field to women the past two decades in the United States. Similar numbers of males and females run on high school and college teams and in road races. Female runners have been competing for equal shares of prize money and receiving nearly 50 percent more scholarship aid from Division I colleges than their male counterparts, according to the N.C.A.A.

But these social changes have not shrunk a gender gap among runners analyzed by Robert Deaner, a psychologist at Grand Valley State University in Michigan, who classifies runners as relatively fast if they keep close to the pace of the world’s best runners of their own sex. When Dr. Deaner looks at, say, the top 40 finishers of each sex in a race, he typically finds two to four times as many relatively fast male runners as relatively fast female runners.

This large gender gap has persisted for two decades in all kinds of races — high school and college meets, elite and nonelite road races — and it jibes with other studies reporting that male runners train harder and are more motivated by competition, Dr. Deaner says. This enduring “sex difference in competitiveness,” he concludes, “must be considered a genuine failure for the sociocultural conditions hypothesis” that the personality gap will shrink as new roles open for women.

If he and Dr. Schmitt are right, then men and women shouldn’t expect to understand each other much better anytime soon. Things could get confusing if the personality gap widens further as the sexes become equal. But then, maybe it was that allure of the mysterious other that kept Mars and Venus together so long on the savanna.

Wednesday, September 03, 2008

Swedish Researchers Say 40 Percent Of Men Possess Gene Linked To Infidelity Among Voles

Male infidelity may be in genes
Genetic variant keys marital ill
By Shankar Vedantam
The Washington Post
Article Last Updated: 09/02/2008 11:20:52 PM MDT

Men are more likely to be devoted and loyal husbands when they lack a particular variant of a gene that influences brain activity, researchers announced this week — the first time that science has shown a direct link between a man's genes and his aptitude for monogamy.

The finding is striking because it not only links the gene variant — which is present in two of every five men — with the risk of marital discord and divorce, but also appears to predict whether women involved with these men are likely to say their partners are emotionally close and available, or distant and disagreeable. The presence of the gene variant, or allele, also seems predictive of whether men get married or live with women without getting married.

"Men with two copies of the allele had twice the risk of experiencing marital dysfunction, with a threat of divorce during the last year, compared to men carrying one or no copies," said Hasse Walum, a behavioral geneticist at the Karolinska Institute in Stockholm who led the study. "Women married to men with one or two copies of the allele scored lower on average on how satisfied they were with the relationship compared to women married to men with no copies."

The scientists studied men because the hormone being examined is known to play a larger role in their brains than in women's brains.

The finding set off a debate about whether people should conduct genetic tests to find out whether potential mates are bad marriage prospects. Several independent scientists called the discovery remarkable and elegant but disagreed over whether such information ought to be used in making personal decisions about love and marriage.

Walum said that the presence of the allele increased the risk of conjugal discord but that many other factors probably shape marital behavior. But he and other scientists said the study is the latest piece of evidence to show that biology — down to the level of individual genes — can play a powerful role in shaping complex human behavior.

In other words, if a man's culture, religion and family background each have a seat at the conference table that determines his attitudes toward marital fidelity and monogamy, his genes might well sit at the head of the table.

"There are many ways this information can help a man and his wife when they marry," said Helen Fisher, a biological anthropologist at Rutgers University who studies romantic love. "Knowing there are biological weak links can help you overcome them."

Tuesday, September 02, 2008

Why Jamaican Runners did so well in the Olympics: the 'T' Factor

Excerpted from "The Athletic Prowesss of Jamaicans" by William Aiken,M.D., Jamaica Gleaner, November 22, 2006

"I wish to propose a hypothesis that addresses not only the aspect of Jamaica's raw athletic talent, but also encompasses an explanation of seemingly diverse phenomena as our high incidence of prostate cancer (one study found it to be by far the highest in the world at 304 / 100,000 men / year), our high crime rate (murder capital of the world status earlier this year), our high road traffic accident and fatality rate, and our alleged high levels of promiscuity.

What do these seemingly disparate phenomena, characteristic of Jamaican life, have in common? On close examination these phenomena are manifestations of high levels of aggressiveness and drive, high libidos, highly efficient muscles from persons of lean body mass and black ethnicity. On closer scrutiny all of these phenomena are either related to high circulating levels of testosterone or alternatively to high levels of responsiveness of testosterone receptors to circulating testosterone.

It has already been shown that the testosterone receptors of blacks are different genetically to those of whites and this difference confers increased responsiveness to testosterone. I propose that Jamaicans of primarily African descent have even greater testosterone responsiveness than blacks anywhere else.

The middle passage

But why should this be? I believe the answer to this lies in the slave ship routes within the Caribbean and the New World.

First, let us assume that all Africans who survived the trek from the African interior to the West African coast and subsequently the middle passage would have been more or less subject to the same inhumane conditions which would have produced a severe selection pressure that enabled only the fittest slaves to survive the journey.

My hypothesis is that for each incremental increase in the journey travelled, once the slave ships entered the Caribbean, there was a corresponding selection pressure which ensured that only the fittest of the fit slaves survived and furthermore the traits which enabled survival were somehow dependent on high levels of responsiveness to testosterone.

Characteristics such as aggression, determination, drive, strong bones, lean body mass, high surface area to body mass ratio, highly efficient and responsive muscles were probably all important for survival and are testosterone-dependent.

Since Jamaica was one of the last stops to be made by the slave ships it ensured that only the most resilient and fittest of slaves were alive to disembark in Jamaica.

This hypothesis is supported by a number of observations. African-Americans and Afro-Caribbean people are represented far more frequently in sprinting events than persons from Africa. Even more interesting is that as one goes westward within the Caribbean, sprinting prowess becomes more prevalent and reaches its peak by the time Jamaica and Bahamas are reached.

This hypothesis in no way minimises the important contributions of good sport administration, excellent coaching and proper nutrition but rather looks at one aspect of the puzzle in attempting to explain the raw athletic talent that seems to be disproportionately high in Jamaicans."

Dr. William Aiken is the head of Urology at the University Hospital of the West Indies and president of the Jamaica Urological Society; email: yourhealth@gleanerjm.com.

Feminism and Freedom

Thomas Carlyle has ascribed the insights of genius to "cooperation with the tendency of the world."

“It is time to leave the question of the role of women in society up to Mother Nature--a difficult lady to fool. You have only to give women the same opportunities as men, and you will soon find out what is or is not in their nature. What is in women's nature to do they will do, and you won't be able to stop them. But you will also find, and so will they, that what is not in their nature, even if they are given every opportunity, they will not do, and you won't be able to make them do it.”

-Clare Boothe Luce, a conservative feminist who in her heyday in the 1940s was a popular playwright and a member of the U.S. Congress,

We know from common observation that women are markedly more nurturing and empathetic than men. The female tendency to be empathic and caring shows up very early in life. Female infants, for example, show greater distress and concern than male infants over the plight of others; this difference persists into adulthood. Women do not merely say they want to help others; they enter the helping and caring professions in great numbers. Even today, in an era when equal rights feminism is dominant in education, the media, and the women's movement, women continue to be vastly overrepresented in fields like nursing, social work, pediatrics, veterinary medicine, and early childhood education. The great nineteenth-century psychologist William James said that for men "the world is a theater for heroism." That may be an overstatement, but it finds a lot of support in modern social science--and evidence from everyday life. Women are numerically dominant in the helping professions; men prevail in the saving and rescuing vocations such as policemen, firefighters, and soldiers.

-Christine Hoff Sommers
Excerpted from Feminism and Freedom
AEI Online

Monday, July 14, 2008

A New Frontier for Title IX: Science

July 15, 2008
New York Times

Until recently, the impact of Title IX, the law forbidding sexual discrimination in education, has been limited mostly to sports. But now, under pressure from Congress, some federal agencies have quietly picked a new target: science.

The National Science Foundation, NASA and the Department of Energy have set up programs to look for sexual discrimination at universities receiving federal grants. Investigators have been taking inventories of lab space and interviewing faculty members and students in physics and engineering departments at schools like Columbia, the University of Wisconsin, M.I.T. and the University of Maryland.

So far, these Title IX compliance reviews haven’t had much visible impact on campuses beyond inspiring a few complaints from faculty members. (The journal Science quoted Amber Miller, a physicist at Columbia, as calling her interview “a complete waste of time.”) But some critics fear that the process could lead to a quota system that could seriously hurt scientific research and do more harm than good for women.

The members of Congress and women’s groups who have pushed for science to be “Title Nined” say there is evidence that women face discrimination in certain sciences, but the quality of that evidence is disputed. Critics say there is far better research showing that on average, women’s interest in some fields isn’t the same as men’s.

In this debate, neither side doubts that women can excel in all fields of science. In fact, their growing presence in former male bastions of science is a chief argument against the need for federal intervention.

Despite supposed obstacles like “unconscious bias” and a shortage of role models and mentors, women now constitute about half of medical students, 60 percent of biology majors and 70 percent of psychology Ph.D.’s. They earn the majority of doctorates in both the life sciences and the social sciences. They remain a minority in the physical sciences and engineering. Even though their annual share of doctorates in physics has tripled in recent decades, it’s less than 20 percent. Only 10 percent of physics faculty members are women, a ratio that helped prompt an investigation in 2005 by the American Institute of Physics into the possibility of bias.
But the institute found that women with physics degrees go on to doctorates, teaching jobs and tenure at the same rate that men do. The gender gap is a result of earlier decisions. While girls make up nearly half of high school physics students, they’re less likely than boys to take Advanced Placement courses or go on to a college degree in physics.

These numbers don’t surprise two psychologists at Vanderbilt University, David Lubinski and Camilla Persson Benbow, who have been tracking more than 5,000 mathematically gifted students for 35 years.

They found that starting at age 12, the girls tended to be better rounded than the boys: they had relatively strong verbal skills in addition to math, and they showed more interest in “organic” subjects involving people and other living things. Despite of their mathematical prowess, they were less likely than boys to go into physics or engineering.

But whether they grew up to be biologists or sociologists or lawyers, when they were surveyed in their 30s, these women were as content with their careers as their male counterparts. They also made as much money per hour of work. Dr. Lubinski and Dr. Benbow concluded that adolescents’ interests and balance of abilities — not their sex — were the best predictors of whether they would choose an “inorganic” career like physics.

A similar conclusion comes from a new study of the large gender gap in the computer industry by Joshua Rosenbloom and Ronald Ash of the University of Kansas. By administering vocational psychological tests, the researchers found that information technology workers especially enjoyed manipulating objects and machines, whereas workers in other occupations preferred dealing with people.

Once the researchers controlled for that personality variable, the gender gap shrank to statistical insignificance: women who preferred tinkering with inanimate objects were about as likely to go into computer careers as were men with similar personalities. There just happened to be fewer women than men with those preferences.

Now, you might think those preferences would be different if society didn’t discourage girls and women from pursuits like computer science and physics. But if you read “The Sexual Paradox,” Susan Pinker’s book about gender differences, you’ll find just the opposite problem.

Ms. Pinker, a clinical psychologist and columnist for The Globe and Mail in Canada (and sister of Steven Pinker, the Harvard psychologist), argues that the campaign for gender parity infantilizes women by assuming they don’t know what they want. She interviewed women who abandoned successful careers in science and engineering to work in fields like architecture, law and education — and not because they had faced discrimination in science.

Instead, they complained of being pushed so hard to be scientists and engineers that they ended up in jobs they didn’t enjoy. “The irony was that talent in a male-typical pursuit limited their choices,” Ms. Pinker says. “Once they showed aptitude for math or physical science, there was an assumption that they’d pursue it as a career even if they had other interests or aspirations. And because these women went along with the program and were perceived by parents and teachers as torch bearers, it was so much more difficult for them to come to terms with the fact that the work made them unhappy.”

Ms. Pinker says that universities and employers should do a better job helping women combine family responsibilities with careers in fields like physics. But she also points out that female physicists are a distinct minority even in Western European countries that offer day care and generous benefits to women.

“Creating equal opportunities for women does not mean that they’ll choose what men choose in equal numbers,” Ms. Pinker says. “The freedom to act on one’s preferences can create a more exaggerated gender split in some fields.”

Applying Title IX to science was proposed eight years ago by Debra Rolison, a chemist at the Naval Research Laboratory. She argued that withholding federal money from “poorly diversified departments” was essential to “transform the academic culture.” The proposal was initially greeted, in her words, with “near-universal horror.”

Some female scientists protested that they themselves would be marginalized if a quota system revived the old stereotype that women couldn’t compete on even terms in science. But the idea had strong advocates, too, and Congress quietly ordered agencies to begin the Title IX compliance reviews in 2006.

The reviews so far haven’t led to any requirements for gender balance in science departments. But Christina Hoff Sommers, a resident scholar at the American Enterprise Institute who has written extensively about gender wars in academia, predicts that lawyers will work gradually, as they did in sports, to require numerical parity.

“Colleges already practice affirmative action for women in science, but now they’ll be so intimidated by the Title IX legal hammer that they may institute quota systems,” Dr. Sommers said. “In sports, they had to eliminate a lot of male teams to achieve Title IX parity. It’ll be devastating to American science if every male-dominated field has to be calibrated to women’s level of interest.”

Whether or not quotas are ever imposed, some of the most productive science and engineering departments in America are busy filling out new federal paperwork. The agencies that have been cutting financing for Fermilab and the Spirit rover on Mars are paying for investigations of a problem that may not even exist. How is this good for scientists of either sex?

Study Finds Genetic Link to Violence, Delinquency

By Maggie Fox
Health and Science Editor ~ Yahoo News
Mon Jul 14, 2:16 PM ET

Three genes may play a strong role in determining why some young men raised in rough neighborhoods or deprived families become violent criminals, while others do not, U.S. researchers reported on Monday.

One gene called MAOA that played an especially strong role has been shown in other studies to affect antisocial behavior -- and it was disturbingly common, the team at the University of North Carolina reported.

People with a particular variation of the MAOA gene called 2R were very prone to criminal and delinquent behavior, said sociology professor Guang Guo, who led the study.

"I don't want to say it is a crime gene, but 1 percent of people have it and scored very high in violence and delinquency," Guo said in a telephone interview.

His team, which studied only boys, used data from the National Longitudinal Study of Adolescent Health, a U.S. nationally representative sample of about 20,000 adolescents in grades 7 to 12. The young men in the study are interviewed in person regularly, and some give blood samples.

Guo's team constructed a "serious delinquency scale" based on some of the questions the youngsters answered.

"Nonviolent delinquency includes stealing amounts larger or smaller than $50, breaking and entering, and selling drugs," they wrote in the August issue of the American Sociological Review.

"Violent delinquency includes serious physical fighting that resulted in injuries needing medical treatment, use of weapons to get something from someone, involvement in physical fighting between groups, shooting or stabbing someone, deliberately damaging property, and pulling a knife or gun on someone."


They found specific variations in three genes -- the monoamine oxidase A (MAOA) gene, the dopamine transporter 1 (DAT1) gene and the dopamine D2 receptor (DRD2) gene -- were associated with bad behavior, but only when the boys suffered some other stress, such as family issues, low popularity and failing school.

MAOA regulates several message-carrying chemicals called neurotransmitters that are important in aggression, emotion and cognition such as serotonin, dopamine and norepinephrine.

The links were very specific.

The effect of repeating a grade depended on whether a boy had a certain mutation in MAOA called a 2 repeat, they found.

And a certain mutation in DRD2 seemed to set off a young man if he did not have regular meals with his family.

"But if people with the same gene have a parent who has regular meals with them, then the risk is gone," Guo said.

"Having a family meal is probably a proxy for parental involvement," he added. "It suggests that parenting is very important."

He said vulnerable children might benefit from having surrogates of some sort if their parents are unavailable.

"These results, which are among the first that link molecular genetic variants to delinquency, significantly expand our understanding of delinquent and violent behavior, and they highlight the need to simultaneously consider their social and genetic origins," the researchers said.

Guo said it was far too early to explore whether drugs might be developed to protect a young man. He also was unsure if criminals might use a "genetic defense" in court.

"In some courts (the judge might) think they maybe will commit the same crime again and again, and this would make the court less willing to let them out," he said.
(Editing by Will Dunham)

Monday, June 16, 2008

Gay Men and Heterosexual Women Have Similarly Shaped Brains, Research Shows

Lesbians and heterosexual men show same pattern· Findings may throw light on depression and autism

Ian Sample, science correspondent
The Guardian

Tuesday June 17 2008

Striking similarities between the brains of gay men and straight women have been discovered by neuroscientists, offering fresh evidence that sexual orientation is hardwired into our neural circuitry.

Scans reveal homosexual men and heterosexual women have symmetrical brains, with the right and left hemispheres almost exactly the same size. Conversely, lesbians and straight men have asymmetrical brains, with the right hemisphere significantly larger than the left.

Scientists at the prestigious Stockholm Brain Institute in Sweden also found certain brain circuits linked to emotional responses were the same in gay men and straight women.

The findings, published tomorrow in the US journal Proceedings of the National Academy of Sciences, suggest the biological factors that influence sexual orientation - such as exposure to testosterone in the womb - may also shape the brain's anatomy.

The study, led by the neurobiologist Ivanka Savic, builds on previous research that has identified differences in spatial and verbal abilities related to sex and sexual orientation. Tests have found gay men and straight women fare better at certain language tasks, while heterosexual men and lesbians tend to have better spatial awareness.

Savic and her colleague Per Linström took MRI brain scans of 90 volunteers who were divided into four groups of similar ages according to whether they were male, female, heterosexual or homosexual. The scans showed the right side of the brain in heterosexual men was typically 2% larger than the left. Lesbians showed a similar asymmetry, with the right hand side of the brain 1% larger than the left.

Scans on homosexual men and heterosexual women revealed both sides of the brain were the same size.

The results could explain a University of London study earlier this year that found gay men and straight women share a poor sense of direction compared with heterosexual men, and were more likely to navigate using landmarks alone.

The right hand side of the brain dominates spatial capabilities, so may be slightly more developed in heterosexual men and lesbians. An earlier study by the same team found gay men and straight women outperformed lesbians and straight men at tasks designed to test verbal fluency.

Savic's team has yet to confirm whether the differences in brain shape are responsible for sexual orientation, or are a consequence of it. To find out, they have begun another study to investigate brain symmetry in newborn babies, to see if it can be used to predict their future sexual orientation.

"These differences might be laid down during brain development in the womb, or they could happen after birth, though it could very likely be a combination of the two," said Savic.

In another series of tests, Savic and Lindström used a technique called positron emission tomography (PET) to look at brain wiring in a smaller group of volunteers. They found heterosexual women and gay men shared brain circuitry linking a region called the amygdala, which plays a key role in emotional responses, to other parts of the brain.

The research is part of a larger effort to identify differences between the male and female brain, in the hope they will shed light on why some mental disorders affect men and women differently. For example, major depressive disorders are far more common and persistent in women, while autism is around four times more common in boys than girls.

"There's a well known uneven sex distribution in the number of psychiatric disorders and trying to understand sex differences, and differences in orientation, may give you a hint of the mechanism underlying these diseases," said Savic.

Thursday, May 15, 2008

Testosterone and paternal investment

As modern humans moved north into environments with longer winters, women were less able to feed themselves and their children through food gathering. They thus became more dependent on food from their male partners. For men, this greatly increased the cost of having a wife and children, thus making polygyny prohibitively expensive for all but the ablest hunters.

Initially, this situation came about by men and women pushing their respective envelopes of behavioral plasticity. It may not have been the happiest of situations, but circumstances left no other choice.Over time, however, natural selection should have improved things by favoring men who were less predisposed to polygyny and more predisposed to provide for their wives and children.

How? Apparently, by lowering testosterone levels in men once they've entered a pair bond. This has been shown by findings recently presented at this year's annual meeting of the American Association of Physical Anthropologists. According to Shur et al. (2008):

"Numerous studies reveal a negative correlation between testosterone concentration and paternal care in diverse mammals including non human primates and humans. Several researchers suggest that spousal investment accounts for the lower testosterone of married men compared to unmarried men, but findings that the lowest testosterone levels are observed in married men with children implicate paternal care as particularly relevant. Thus testosterone reduction may reflect a facultative shift in male reproductive strategy from intrasexual competition and copulation to care of young.

This hypothesis was tested with wild olive baboons, among whom lactating females form close 'friendships' with their male partners.In contrast to control males, male friends experienced a decrease in testosterone level coinciding with the birth of their female friends'infants. Male friends also maintained a lower basal testosterone level than did control males during the lactation period of their female friends. Testosterone levels in male friends increased gradually corresponding with developing infant independence.

This finding may explain the marked differences in testosterone levels we see in humans, particularly between tropical and non-tropical populations. These levels seem to decrease wherever men compete less keenly for mates (because polygyny is less common) and wherever they invest more in parenting. Lowering the level of testosterone seems to lower the threshold for expression of paternal investment.

If the testosterone level has fallen in some populations because of selection for paternal investment, we should see evidence of such selection elsewhere, e.g., altered spatial distribution of testosterone receptors in the brain, more mental space dedicated to parenting behavior...."

Respecting - And Recognizing - American D.N.A.

By Michael Medved

...[T]wo respected professors of psychiatry have recently come out with challenging books that contend that those who chose to settle this country in every generation possessed crucial common traits that they passed on to their descendents. In “American Mania,” Peter C. Whybrow of U.C.L.A. argues that even in grim epochs of starvation and persecution, only a small minority ever chooses to abandon its native land and to venture across forbidding oceans to pursue the elusive dream of a better life. The tiny percentage making that choice (perhaps only 2%, even in most periods of mass immigration) represents the very essence of a self-selecting group. Compared to the Irish or Germans or Italians or Chinese or Mexicans who remained behind in the “Old Country,” the newcomers to America would naturally display a propensity for risk-taking, for restlessness, for exuberance and self-confidence –traits readily passed down to subsequent generations. Whybrow explained to the New York Times Magazine that immigrants to the United States and their descendents seemed to possess a distinctive makeup of their “dopamine receptor system – the pathway in the brain that figures centrally in boldness and novelty seeking.”

John D. Gartner of Johns Hopkins University Medical School makes a similar case for an American-specific genotype in “The Hypomanic Edge”—celebrating the frenzied energy of American life that’s impressed every visitor since Tocqueville. The United States also benefited from our tradition of limited government, with only intermittent and ineffective efforts to suppress the competitive, entrepreneurial instincts of the populace. Professor Whybrow says: “Here you have the genes and the completely unrestricted marketplace. That’s what gives us our peculiar edge.” In other words, “anything goes capitalism” reflects and sustains the influence of immigrant genetics....

Wednesday, April 09, 2008

Genes, bad parenting keys to violence

From correspondents in London
April 10, 2008 04:00am

WHETHER a criminal teenager turns into a violent adult or grows out of crime, may be related to how low his ears are set or the types of food he was given as a child.

International research shows antisocial behaviour in young adults can be written into their genetic code, and made worse by bad parenting.

Indicators that an antisocial child may turn into a life-long violent criminal can be picked up in kindergarten, according to research summarised in this week's New Scientist magazine.

Of the 535 males and 502 females born in New Zealand in 1972 and 1973 who were signed up at birth to the University of Dunedin's Multidisciplinary Health and Development Study, those who dabbled in crime as a teenager can be divided into two clear groups, Terrie Moffitt from the Institute of Psychiatry in London said.

The more common type took up petty crime in adolescence keen to impress "badass" friends, she said.

But the more problematic type had biological predispositions to behaviour problems, the signs of which could be picked up as young as three years of age.

These children - more often boys - tended to have a low IQ, poor language skills, and were often diagnosed with attention-deficit hyperactivity disorder.

Minor physical anomalies such as low-seated ears or furrowed tongues - possibly a sign of poor neural development or damage - could also be signs.

Combined with bad parenting, poverty or abuse, these children were at greater risk of turning to a life-long criminal career, she said.

The early onset group accounted for only 10 per cent of the Dunedin males, but by the age of 26 they had accrued almost half of the violent convictions for the entire study.

Ms Moffitt's study of the Dunedin children also focused on the activity of an enzyme linked to aggression in both animals and humans.

By itself, the activity of the enzyme had little influence, but if the boys were more predisposed to aggression and had suffered some abuse as children they were three times as likely to be diagnosed with conduct disorder in adolescence and 10 times as likely to have been convicted of a violent crime in adulthood.

A US study has found there is a worrying subset of kids within the early onset group who do not react emotionally at all, scoring high in tests used for diagnosing adult psychopathy.

A study at the University of New Orleans found the 30 per cent of early onset antisocial children who showed these traits were most likely to turn to life-long violence.

Children in this group lack empathy and guilt, are thrill-seeking, fearless and narcissistic, says psychopathy expert James Blair from the National Institute of Mental Health in the United States.

Learning to fear punishment or recognise someone else's fear or sadness is difficult for psychopaths, he said.

"If they want something and punching someone in the face is the way to extract it, they might be more likely to engage in that kind of behaviour," he said.

Mr Blair said there are few signs that these psychopathic traits are caused by external factors like poor parenting or abuse, but they could be triggered by social forces like poverty.

The generally accepted approach to tackling the problem of antisocial and violent children is to intervene as young as possible with improved parenting.

Some experts say better parenting could even begin before birth.

A trial of monthly nurse visits throughout pregnancy and until the child's second birthday, in New York in the late 1970s, has been praised by scientists at the University of Colorado.

By the age of 15, the 315 children involved in the trial had only half of the number of arrests, one fifth the number of convictions, smoked and drank less and were less promiscuous than their untreated contemporaries.

Source: News.com.au

Negligent, attentive mouse mothers show biological differences

Photo: Jeff Miller

In mice, child neglect is a product of both nature and nurture, according to a new study. Writing in the journal PLoS ONE on April 9, researchers from the University of Wisconsin-Madison describe a strain of mice that exhibit unusually high rates of maternal neglect, with approximately one out of every five females failing to care for her offspring.

By comparing the good mothers to their less attentive relatives, the group has found that negligent parenting seems to have both genetic and non-genetic influences, and may be linked to dysregulation of the brain signaling chemical dopamine.

As a possible model for human child neglect, these mice offer a valuable opportunity to investigate the biological and behavioral bases of naturally occurring maternal neglect, say UW-Madison zoology professor Stephen Gammie, who led the study, and co-author psychology professor Anthony Auger.

Good mouse mothers suckle, groom, and protect their pups, while their neglectful sisters may start out trying to care for a litter, but fail to follow through. "There seems to be a switch early on. The neglectful mice may nurse for a day or two after birth, but then the parental care ceases," Gammie says.

To separate the effects of genes and environment, the researchers set up a fostering study, in which pups born to previously nurturing mothers and previously neglectful mothers were switched immediately after birth.

Surprisingly, while nurturing moms attentively cared for foster pups born to other nurturing females, some became more neglectful when given foster pups born to a neglectful mother.

"In some cases the previously nurturing mothers would actively scatter the pups away from the nest, suggesting a negative cue from the pups or a lack of a positive cue," Gammie says. The result suggests that the offspring are somehow able to influence females' behavior and shows that maternal care can be affected by non-genetic factors.

In the fostering study, previously neglectful mothers did successfully raise some of the pups born to previously nurturing mothers, but these surviving pups showed lasting effects, including hyperactivity and low adult body weight. Some females neglected as youngsters were also poor mothers as adults, suggesting some aspects of neglect can be transmitted across generations.

The group also found evidence of genetic factors contributing to neglect. For example, virgin females that exhibited poor self-grooming and hyperactive behavior were at greater risk for becoming neglectful mothers.

To identify possible biological differences, the researchers analyzed brains of neglectful and nurturing mothers shortly after birth. In several brain regions - including some implicated in both maternal behaviors and reward responsiveness - they found higher levels of activity as well as signs of abnormal dopamine signaling in the neglectful mothers.

These patterns suggest that naturally occurring maternal neglect in these mice reflects disrupted reward-seeking behavior, Gammie says. In other words, these females may have the physical capability to take care of their pups, but may lack the proper motivation.

"It's been shown in a number of studies that parental care is a motivated, reward-related behavior," he says. "And it has been suggested by others that some aspects of child neglect in humans could result from a lack of reward of an offspring to the parent."

Though often overshadowed by more visible abuse cases, human child neglect may actually be a more widespread problem. A report published last week by the Centers for Disease Control and Prevention on U.S. children found that, among infants less than a week old, nearly 70 percent of nonfatal mistreatment cases from 2005 to 2006 were instances of neglect.

Child neglect has devastating consequences, Auger says, and the natural occurrence of maternal neglect within this mouse strain offers a powerful opportunity to investigate the biological and behavioral bases of maternal neglect.

Though he cautions that it's too early to know how their findings will translate to humans, for the mice "the difference is quite dramatic in the brain. Dopamine is likely not the only thing being disrupted, but it is an important starting signaling pathway to pursue."

Next, Auger says, "We hope to understand in greater detail the basis of naturally occurring neglect and provide treatment paradigms to these animals to restore natural maternal care of offspring."

Source: University of Wisconsin-Madison

Culture Can Change our Genes


Physician and social scientist, Harvard

I work in a borderland between social science and medicine, and I
therefore often find myself trying to reconcile conflicting facts and
perspectives about human biology and behavior. There are fellow
travelers at this border, of course, heading in both directions, or
just dawdling, but the border is both sparsely populated and
chaotic. The border is also, strangely, well patrolled, and it is
often quite hard to get authorities on both sides to coordinate
activities. Once in a while, however, I find that my passport (never
quite in order, according to officials) has acquired a new visa. For
me, this past year, I acquired the conviction that human evolution
may proceed much faster than I had thought, and that humans
themselves may be responsible.

In short, I have changed my mind about how people come literally to
embody the social world around them. I once thought that we
internalized cultural factors by forming memories, acquiring
language, or bearing emotional and physical marks (of poverty, of
conquest). I thought that this was the limit of the ways in which
our bodies were shaped by our social environment. In particular, I
thought that our genes were historically immutable, and that it was
not possible to imagine a conversation between culture and genetics.
I thought that we as a species evolved over time frames far too long
to be influenced by human actions.

I now think this is wrong, and that the alternative — that we are
evolving in real time, under the pressure of discernable social and
historical forces — is true. Rather than a monologue of genetics, or
a soliloquy of culture, there is a dialectic between genetics and

Evidence has been mounting for a decade. The best example so far is
the evolution of lactose tolerance in adults. The ability of adults
to digest lactose (a sugar in milk) confers evolutionary advantages
only when a stable supply of milk is available, such as after milk-
producing animals (sheep, cattle, goats) have been domesticated. The
advantages are several, ranging from a source of valuable calories to
a source of necessary hydration during times of water shortage or
spoilage. Amazingly, just over the last 3-9 thousand years, there
have been several adaptive mutations in widely separated populations
in Africa and Europe, all conferring the ability to digest lactose
(as shown by Sarah Tishkoff and others). These mutations are
principally seen in populations who are herders, and not in nearby
populations who have retained a hunter/gatherer lifestyle. This trait
is sufficiently advantageous that those with the trait have notably
many more descendants than those without.

A similar story can be told about mutations that have arisen in the
relatively recent historical past that confer advantages in terms of
surviving epidemic diseases such as typhoid. Since these diseases
were made more likely when the density of human settlements increased
and far-flung trade became possible, here we have another example of
how culture may affect our genes.

But this past year, a paper by John Hawks and colleagues in PNAS
functioned like the staccato plunk of a customs agent stamping my
documents and waving me on. The paper showed that the human genome
may be changing at an accelerating rate over the past 80,000 years,
and that this change may be in response not only to population growth
and adaptation to new environments, but also to cultural developments
that have made it possible for humans to sustain such population
growth or survive in such environments.

Our biology and our culture have always been in conversation of
course — just not (I had thought) on the genetic level. For example,
rising socio-economic status with industrial development results in
people becoming taller (a biological effect of a cultural
development) and taller people require architecture to change (a
cultural effect of a biological development). Anyone marveling at
the small size of beds in colonial-era houses knows this firsthand.
Similarly, an epidemic may induce large-scale social changes,
modifying kinship systems or political power. But genetic change
over short time periods? Yes.

Why does this matter? Because it is hard to know where this would
stop. There may be genetic variants that favor survival in cities,
that favor saving for retirement, that favor consumption of alcohol,
or that favor a preference for complicated social networks. There
may be genetic variants (based on altruistic genes that are a part of
our hominid heritage) that favor living in a democratic society,
others that favor living among computers, still others that favor
certain kinds of visual perception (maybe we are all more myopic as a
result of Medieval lens grinders). Modern cultural forms may favor
some traits over others. Maybe even the more complex world we live
in nowadays really is making us smarter.

This has been very difficult for me to accept because, unfortunately,
this also means that it may be the case that particular ways of
living create advantages for some, but not all, members of our
species. Certain groups may acquire (admittedly, over centuries)
certain advantages, and there might be positive or negative feedback
loops between genetics and culture. Maybe some of us really are
better able to cope with modernity than others. The idea that what
we choose to do with our world modifies what kind of offspring we
have is as amazing as it is troubling.

Wednesday, March 26, 2008

Lizards Undergo Rapid Evolution after Introduction to a New Home

In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the South Adriatic Sea, to the neighboring island of Pod Mrcaru. Now, an international team of researchers has shown that introducing these small, green-backed lizards, Podarcis sicula, to a new environment caused them to undergo rapid and large-scale evolutionary changes.

"Striking differences in head size and shape, increased bite strength and the development of new structures in the lizard's digestive tracts were noted after only 36 years, which is an extremely short time scale," says Duncan Irschick, a professor of biology at the University of Massachusetts Amherst. "These physical changes have occurred side-by-side with dramatic changes in population density and social structure." Results of the study were published March 25 in Proceedings of the National Academy of Sciences.

Researchers returned to the islands twice a year for three years, in the spring and summer of 2004, 2005 and 2006. Captured lizards were transported to a field laboratory and measured for snout-vent length, head dimensions and body mass. Tail clips taken for DNA analysis confirmed that the Pod Mrcaru lizards were genetically identical to the source population on Pod Kopiste.

Observed changes in head morphology were caused by adaptation to a different food source. According to Irschick, lizards on the barren island of Pod Kopiste were well-suited to catching mobile prey, feasting mainly on insects. Life on Pod Mrcaru, where they had never lived before, offered them an abundant supply of plant foods, including the leaves and stems from native shrubs. Analysis of the stomach contents of lizards on Pod Mrcaru showed that their diet included up to two-thirds plants, depending on the season, a large increase over the population of Pod Kopiste.

"As a result, individuals on Pod Mrcaru have heads that are longer, wider and taller than those on Pod Kopiste, which translates into a big increase in bite force," says Irschick. "Because plants are tough and fibrous, high bite forces allow the lizards to crop smaller pieces from plants, which can help them break down the indigestible cell walls."

Examination of the lizard's digestive tracts revealed something even more surprising. Eating more plants caused the development of new structures called cecal valves, designed to slow the passage of food by creating fermentation chambers in the gut, where microbes can break down the difficult to digest portion of plants. Cecal valves, which were found in hatchlings, juveniles and adults on Pod Mrcaru, have never been reported for this species, including the source population on Pod Kopiste.

"These structures actually occur in less than 1 percent of all known species of scaled reptiles," says Irschick. "Our data shows that evolution of novel structures can occur on extremely short time scales. Cecal valve evolution probably went hand-in-hand with a novel association between the lizards on Pod Mrcaru and microorganisms called nematodes that break down cellulose, which were found in their hindguts."

Change in diet also affected the population density and social structure of the Pod Mrcaru population. Because plants provide a larger and more predictable food supply, there were more lizards in a given area on Pod Mrcaru. Food was obtained through browsing rather than the active pursuit of prey, and the lizards had given up defending territories.

"What is unique about this finding is that rapid evolution can affect not only the structure and function of a species, but also influence behavioral ecology and natural history," says Irschick.

Source: University of Massachusetts Amherst

Wednesday, March 19, 2008

The bioecological model

An email sent to Kristin Jacobson, Assistant Professor, University of Chicago Medical School

Dear Prof. Jacobson,

I was just leafing through my University of Chicago Magazine this evening when I came across the article summarizing your new grant. I have to say I was amazed. Though the author tiptoed around the area under investigation, you are entering some very choppy waters. The attempt to identify the genetic and biological contributions to anti social behavior and cognition is normally considered taboo, since it inevitably ventures into racial variables. Though I am familiar with some work reported in press releases and abstracts of journals, as you can see from my weblog, most researchers, considering the downside, tend to avoid such studies, even with the best of intentions.

I can't help be reminded of the unfortunate lesson of Chicago's Dr. Bruce Lahn, with whom you undoubtedly have discussed your research interests. As was noted several years ago in the Wall Street Journal: The university's patent office is also having second thoughts. Its director, Alan Thomas, says his office is dropping a patent application filed last year that would cover using Dr. Lahn's work as a DNA-based intelligence test. "We really don't want to end up on the front page...for doing eugenics," Mr. Thomas says. Lahn himself has backed away from the research that brought him so much notoreity and made Univeristy officials "nervous". As the Journal reported Lahn saying about the neurogenetics: "It's getting too controversial." Won't Dean Madera and Media Relations Director John Easton, or their successors, be equally concerned about what you might turn up? Lawrence Summers was hounded out of the presidency of Harvard for just injecting some off the cuff and off the record speculation about neurological gender differences that flow from the data.

I commend you for your courage, since I do believe with you that empirical evidence about the interplay of nature and nurture should inform our public policy decisions.


Tom Merle
M.A. '74

Teenagers behaving badly
Univerity of Chicago Magazine, Mar/April '08


They’re getting high off cold meds, posting lewd photos on MySpace, and developing online gambling addictions. The sins may be new, but problem behavior has long been a rite of passage for U.S. teens. In fact, says behavioral geneticist Kristen Jacobson, troublemaking is so common for Americans between ages 14 and 18 that “it’s almost normative.” Yet individual differences abound. Why do some youths make relatively harmless crank calls while others wield knives and bully classmates? Why do some emerge from adolescence as well-adjusted adults while others sink into a cycle of delinquent behavior? Jacobson, an assistant professor of psychiatry, wants to understand the divergence. With a $1.5 million National Institutes of Health New Innovator Award she won this past September, she’ll study how environmental and genetic influences interact to shape adolescent conduct, including nonviolent delinquency, aggression, and substance abuse.

When delinquency persists past adolescence, Jacobson says, genes may be partly to blame.
“People may be acting out for genetic reasons, but they may be acting out for environmental reasons as well,” says Jacobson. Known as the “bioecological model,” her chosen approach sees individual development as a set of interactions between genes and environmental factors such as family, school, and community. Much of Jacobson’s research on teens has focused on twin studies, and she is associate director of the psychiatry department’s twin-studies program. By comparing identical twins, who share all of their DNA, with fraternal twins, who share only half, geneticists can better pinpoint which behaviors may be genetically linked.

Jacobson describes many of the environmental influences she studies as “grandmother science,” or things a typical grandmother might warn her grandchild about. Peer pressure is one example. “Kids who hang out with other kids who do bad things tend to get in trouble,” she says. In fact, most problem behavior, both aggression and nonviolent delinquency, such as lying to parents and stealing, drops off as teens grow up and leave high school.

Yet some adolescents exhibit more lasting problems. In research conducted in 2003, Jacobson analyzed twin-studies data to identify two pathways of antisocial conduct: adolescent-limited and life-course persistent. Each is characterized by a different degree of heritability, or genetic influence. The first group, which makes up roughly 50–75 percent of troubled teens, describes those whose acting out, influenced mainly by environmental factors, tapers off after adolescence.

Children whose difficulties continue, on the other hand, make up less than ten percent of the population and exhibit higher genetic influence. They often act out earlier in life and score higher on early-childhood tests that measure maternal depression, maternal life stress, low socioeconomic status, single parenthood, home environment, and parental treatment.

As genetic technology improves and more human-development researchers seek out the individual genes that influence behavior, Jacobson continues to stress the importance of environmental variables, which may even alter how genes express themselves. A 2005 study in the Proceedings of the National Academy of Sciences, for example, found variation in identical twins’ DNA methylation levels, a driver of gene expression. Because both siblings have the same gene set, says Jacobson, whose NIH study builds on these findings, such a divergence may result from environmental influences—the level of maternal care in infancy is one example—that cause twins’ genes to express themselves differently.

If the way a parent treats a child can change the body’s biology, Jacobson reasons, so might other environmental influences. Recent functional magnetic resonance imaging (fMRI) studies, for example, link early-life family adversity with decreased activity in the amygdala, the part of the brain related to emotion regulation and believed to play a role in developing aggressive behavior.

Understanding how deviance develops on both genetic and environmental levels could offer new ideas on how to help at-risk teens. Researchers have long observed that children from low socioeconomic environments, a group over-represented by racial and ethnic minorities, show the worst developmental outcomes. Furthermore, the influence of genes on those outcomes may be different from other populations. As a graduate student at Pennsylvania State University, Jacobson coauthored a 1999 paper in Child Development finding that genetic influence on verbal IQ varied depending on parents’ education levels. For children from a highly educated family, genetic influence was greater than for those with less education. In other words, says Jacobson, environmental influences played a larger role on verbal IQ for the disadvantaged. [this does not follow]

Over the next five years her NIH study will investigate the environmental, psychosocial, biological, and genetic risk components of delinquency across socioeconomic and racial groups. The multidisciplinary project—one of the only large-scale genetic studies of adolescent delinquency to look at ethnicity and socioeconomic status beyond Caucasians—will use in-school surveys, interviews, computer-based tests of traits like impulsivity, and fMRI to parse the effects of nature and nurture....

Jacobson emphasizes that her project, an attempt to cull data at several levels, is more exploratory than hypothesis-driven. Thus while it would be premature for her to speculate on what intervention programs might best help at-risk teens, her work should shed light on why some kids struggle while others thrive. For teens whose bad behavior—not to mention whose parents and teachers—cries out for real-world solutions, Jacobson is laying critical groundwork.

Saturday, March 15, 2008

"...the biological pressures that whisper within men."

Do you Want a Man.... or a Worm?

Los Angeles Times
Among mammals, expecting monogamy tends to run against the grain of nature.
By David P. Barash
March 12, 2008
As an evolutionary biologist, I look at New York Gov. Eliot Spitzer's now-public sexual indiscretions and feel justified in saying, "I told you so."

One of the most startling discoveries of the last 15 years has been the extent of sexual infidelity (scientists call it "extra-pair copulations" or EPCs) among animals long thought to be monogamous. It's clear that social monogamy -- physical association and child rearing between a male and a female -- and sexual monogamy are very different things. The former is common; the latter is rare.

At one point in the movie "Heartburn," Nora Ephron's barely fictionalized account of her marriage to reporter Carl Bernstein, the heroine tearfully tells her father about her husband's infidelities, only to be advised, "You want monogamy? Marry a swan." Yet thanks to DNA evidence, we know now that even those famously loyal swans aren't sexually monogamous.

One species that is, and, significantly, perhaps the only one that could be reliably designated as such, is Diplozöon paradoxum, a parasitic worm that inhabits the intestines of fish. Among these animals, male and female pair up while adolescents; their bodies literally fuse together, whereupon they remain sexually faithful until death does not them part.

One of the most important insights of modern evolutionary biology has been an enhanced understanding of male-female differences, deriving especially from the production of sperm versus eggs. Because sperm are produced in vast numbers, with little if any required parental follow-through, males of most species are aggressive sexual adventurers, inclined to engage in sex with multiple partners when they can. Males who succeed in doing so leave more descendants.

A story is told in New Zealand about the early 19th century visit of an Episcopal bishop to an isolated Maori village. As everyone was about to retire after an evening of high-spirited feasting and dancing, the village headman -- wanting to show sincere hospitality to his honored guest -- called out, "A woman for the bishop." Seeing a scowl of disapproval on the prelate's face, the host roared even louder, "Two women for the bishop!"

On balance, the Maori headman had an acute understanding of men. He also reflected a powerful cross-cultural universal: Around the world, high-ranking men have long enjoyed sexual access to comparatively large numbers of women, typically young and attractive. Moreover, women have by and large found such men appealing beyond what may be predicted from their immediate physical traits. "Power," wrote Henry Kissinger, "is the ultimate aphrodisiac."

Power-as-pheromone is pretty much the default among mammals. Elk, elephant seal, baboon or chimpanzee, in a wide array of species, females eagerly mate with dominant males while disdaining subordinates. And they do so, more or less, in harems.

Not surprisingly, before the homogenization of cultures that resulted from Western colonialism, more than 85% of human societies unabashedly favored polygamy. In such societies, men who accumulate power, wealth and status gain additional wives and consorts. In avowedly monogamous cultures, successful males accumulate a wife and often additional girlfriends. Even if, thanks to birth control technology, they do not actually reproduce as a result (and thus enhance their evolutionary "fitness"), they are responding to the biological pressures that whisper within men.

Part of being successful, moreover, is a tendency to feel entitled and often to be uninhibited -- in part because one outcome of our species-wide polygamous history is that successful men have been those who took risks, which paid off. The losers were mostly found among the unsuccessful bachelors who, by definition, did not contribute very much to succeeding generations of men, or to their inclinations.

All of which contributes to the apparent sex appeal of such less-than-stunning physical specimens as Kissinger, Woody Allen and Bill Clinton, not to mention the persistence of sex scandals among the popular and powerful across the political and ideological spectrum, including Thomas Jefferson, JFK, Hugh Grant, Newt Gingrich, Larry Craig and a long list, receding almost to the infinite past as well as likely into the indefinite future. For men at the top -- rock stars, successful athletes, politicians, wealthy CEOs, the jet-set glitterati -- such opportunities are exceedingly numerous, not so much because they have insatiable sex drives but because they are dominant males in a biologically randy species.

Some readers may bridle at this characterization of Homo sapiens as EPC-inclined, but the evidence is overwhelming. That doesn't justify adultery, by either sex, especially because human beings -- even those burdened by a Y chromosome and suffering from testosterone poisoning -- are presumed capable of exercising control over their impulses. Especially if, via wedding vows, they have promised to do so. After all, "doing what comes naturally" is what nonhuman animals do. People, most of us like to think, have the unique capacity to act contrary to their biologically given inclinations. Maybe, in fact, it is what makes us human.

But even a smidgen of evolutionary insight suggests that maleness plus money plus political power isn't likely to add up to the kind of sexual restraint that the public expects. A concluding word, therefore, to the outraged voters of New York state: You want monogamy? Elect a swan. Or better yet, a Diplozöon paradoxum.

David P. Barash, an evolutionary biologist, is professor of psychology at the University of Washington.

Impulsive Aggressive Behavior

Nature or nurture - why do some of us see red?

University of Manchester researchers are investigating why some people remain calm in the face of life's niggles, while others 'flip' with little provocation.

Recent studies using new brain-imaging technology have discovered that a change in the brain's neurochemical activity may be related to increased impulsive aggression (when someone unexpectedly reacts violently with little provocation, as opposed to someone deliberately 'looking for trouble'). Now psychologist Angela Rylands wants to deploy the University's world-leading HRRT PET brain scanner, based at its Wolfson Molecular Imaging Centre (WMIC), as part of a project to find out more.

Angela said: "Positron emission tomography (PET) scanning has revealed that a deficit in brain serotonin neurotransmission may leave some people more prone to aggression and impulse control disorders. I want to establish to what extent such behaviours are rooted at a molecular level and how much does learning from the environment around us also play a part."

One of her case studies, 39-year-old former professional bodyguard turned retail manager Carl Hayes, is available for interview. Carl is taking part in order to find out why he loses his temper so easily (he once set light to £800 in a row with his ex-wife).

Angela is looking for other males aged 18 or over, who do not use illegal drugs, and who feel they may be impulsively aggressive to have their brains scanned, to develop the team's understanding of the processes at work. Genetic samples will also be taken to enable them to investigate any interesting polymorphisms (genetic markers which occur in different forms from person to person), as previous research has implicated specific polymorphisms in aggressive behaviour.

Angela will then carry out psychological assessments of participants' previous exposure to aggression and neuropsychological tests to assess their aggressive capacity.

"It's well known that the prefrontal brain regions are associated with normal social and emotional behaviour, and that people with damage to these areas are more impulsive and aggressive," Angela continued. "We now want to see whether subtle deficits in the brain's serotonin system can explain differing levels of aggression in people who don't have brain damage. Our first theory is that higher capacity for impulsive aggression will be found in those with the lowest levels of brain serotonin. The second is that a combination of our genetic makeup and a harsh or abusive childhood may lead to the brain serotonin system not developing normally.

"The areas of serotonin neurotransmission that we are interested in are in the brain regions associated with inhibitory control. Of course people need to take responsibility for their own behaviour, but it could be that some people have difficulties controlling aggression because of impaired regulation of negative emotions or social behaviour by the serotonin system in their brains.

"The genetic samples we take and our assessments of people's exposure to aggression in their childhoods may uncover the factors that adversely influence the developing serotonin system and lead to a dysfunctional system in the mature adult.

"If we can get to the root of impulsive aggressive behaviour - be it nature, nurture or a combination of the two - it could help us to identify how we can break the cycle of impulsive and aggressive behaviour and intervene with future generations at risk from losing control."

She added: "This work may prevent future generations suffering the consequences of impulsive aggression.

"Aggression that occurs as a consequence of poor impulse control presents a burden for society. Each year over half a million people worldwide die from interpersonal violence. The financial burden of violent crime adds to this, incurring expenditures for the criminal justice system, for the incarceration of offenders and to local victims. Socioeconomic costs and public health issues persist, as a consequence of aggressive behaviour.

"The underpinnings of aggression should be identified to enable advancement towards preventative measures."

Participants will visit the WMIC for a screening session, followed by a scan if appropriate. They will then undergo psychological assessments of their previous exposure to aggression, and neuropsychological tests to assess their aggressive capacity. Volunteers will be reimbursed for their time and travel expenses.

Source: University of Manchester

Sunday, March 09, 2008

Hormones, Genes and the Corner Office

The New York Times

March 9, 2008



Men, Women, and the Real Gender Gap.

By Susan Pinker.

340 pp. Scribner. $26.

Why do girls on average lead boys for all their years in the classroom, only to fall behind in the workplace? Do girls grow up and lose their edge, while boys mature and gain theirs?

Ten years ago, no one would have thought to ask. The assumption that boys dominated at school as well as at work, while girls were silenced or ignored, seemed beyond dispute. But in her new book, “The Sexual Paradox,” a ringing salvo in the sex-difference wars, Susan Pinker stacks up the evidence of boys’ classroom woes and girls’ triumphs. “In the United States, boys are three times as likely to be placed in special education classes, twice as likely to repeat a grade and a third more likely to drop out of high school,” she writes. Tests of 15-year-olds in 30 European countries show girls far outstripping boys in reading and writing and holding their own in math. Boys are overrepresented in the top 1 percent of math achievers, but there are also more of them at the bottom. A 2006 economics study showed universities practicing affirmative action for men so that superior female applicants wouldn’t swamp them. “If you were to predict the future on the basis of school achievement alone,” Pinker writes, “the world would be a matriarchy.”

And yet, of course, it is not. Once they move from school to work, men on average earn more money and run more shows. They particularly dominate in national government, the corporate boardroom and the science laboratory. Meanwhile, women are more likely to leave the labor force and to end up with lower pay and less authority if they come back.

Pinker, a psychologist and a columnist at The Globe and Mail in Canada, is careful to remind her readers that statistics say nothing about the choices women and men make individually. Nor does she entirely discount the effect of sex discrimination or culture in shaping women’s choices. But she thinks these forces play only a bit part. To support this, Pinker quotes a female Ivy League law professor: “I am very skeptical of the notion that society discourages talented women from becoming scientists,” the professor writes. “My experience, at least from the educational phase of my life, is that the very opposite is true.” If women aren’t racing to the upper echelons of science, government and the corporate world despite decades of efforts to woo them, Pinker argues, then it must be because they are wired to resist the demands at the top of those fields.

Thus, Pinker parks herself firmly among “difference” feminists. Women’s brains aren’t inferior, she argues, but they vary considerably from men’s, and this is the primary explanation for the workplace gender divide. Women care more about intrinsic rewards, they have broader interests, they are more service-oriented and they are better at gauging the effect they have on others. They are “wired for empathy.” These aren’t learned traits; they’re the result of genes and hormones. Beginning in utero, men are generally exposed to higher levels of testosterone, driving them to be more competitive, assertive, vengeful and daring. Women, meanwhile, get a regular dose of oxytocin, which helps them read people’s emotions, “the truest social enabler.” Then there’s prolactin, which, along with oxytocin, surges during pregnancy, breast-feeding and caretaking. Together, the hormones produce such a high that mother rats choose their newborns over cocaine.

Many of the scientific claims are familiar from previous books that pump up findings on sex difference, like “The Female Brain,” by the neurologist Louann Brizendine. Pinker goes even further by drawing a straight line from those blissed-out rats to human mothers who dial back at work. Because of their biological makeup, she argues, most women want to limit the amount of time they spend at work and to find “inherent meaning” there, as opposed to domination. “Both conflict with making lots of money and rising through the ranks,” she points out.

Pinker is surely right to contest what she calls the “vanilla male model” of success — “that women should want what men want and be heartily encouraged to choose it 50 percent of the time.” Or that when employers say jump, employees should always say how high. Even as they work fewer hours for less status and less money, on average, more women report that they are satisfied with their careers. Maybe men might well think the same if more of them felt they could cut back. But Pinker’s difference feminism doesn’t really allow for that possibility. She is a believer: “The puzzle is why the idea of sex differences continues to be so controversial,” she writes.

In her zeal, Pinker veers to the onesided. She doesn’t acknowledge that some of the research cited in her footnotes is either highly questionable as social science (Louise Story’s 2005 article in The New York Times, for instance, about her survey of Ivy League women’s aspirations) or has never been replicated — like the findings from Simon Baron-Cohen’s laboratory that newborn girls showed more interest in looking at human faces, while newborn boys preferred mechanical mobiles. Pinker omits the work of scientists who have shown that sex-based brain differences pale in comparison to similarities. We shouldn’t wish the role of sex differences away because they’re at odds with feminist dogma. But that doesn’t mean we should settle for the reductionist version of the relevant science, even if the complexity doesn’t make for as neat a package between hard covers.

Pinker also doesn’t acknowledge that some scientists wouldn’t accept the premise behind her chapters about male fragility. She cites men with Asperger’s syndrome and attention deficit disorder as examples of what she calls the “extreme male brain.” These men are train wrecks in school but then get on track in adulthood, when they can focus singlemindedly on their chosen fields. Pinker argues that their experience helps explain the general male lag at school and jump ahead at work. It’s true that men are more likely than women to suffer from Asperger’s and from some forms of A.D.D. But do their particular outsize talents and deficits really shed light on the workings of the average man’s brain? That question is hardly settled, and Pinker seems a bit glib when she fails to say as much.

Pinker also skips past an answer to the book’s central question that may have more explanatory power than her other arguments, even if it’s more prosaic and familiar to many a parent. Boys lag dramatically behind girls in terms of psychological development and physical resilience and then start to catch up as teenagers, as a long-running and wellknown study Pinker cites documented. Maybe after a few years as girls’ developmental equals, boys are ready to compete in the work force — and then zoom ahead as cultural norms and discrimination push women back. After all, why would girls’ hard-wired predilection against competition stay on ice while they blithely sweep all the academic honors and then kick in only at work?

Despite such unanswered questions, Pinker deserves credit for hacking away at the vanilla male model. She is right to point out that “grueling hours do not always translate into productivity” and to seethe at employers for ratcheting up their demands “even while extolling the virtues of gender balance.” And she is also right to call on schools to give the troubles of boys a fair share of attention. Pinker may not convey all the complexity that goes into making many men’s and women’s lives different, but she has a good prescription for helping more of us be our best selves.

Emily Bazelon is a senior editor at Slate.