Showing posts from 2007

human evolution is speeding up

Are Humans Evolving Faster?

Researchers discovered genetic evidence that human evolution is speeding up - and has not halted or proceeded at a constant rate, as had been thought - indicating that humans on different continents are becoming increasingly different.
"We used a new genomic technology to show that humans are evolving rapidly, and that the pace of change has accelerated a lot in the last 40,000 years, especially since the end of the Ice Age roughly 10,000 years ago," says research team leader Henry Harpending, a distinguished professor of anthropology at the University of Utah.

Harpending says there are provocative implications from the study, published online Monday, Dec. 10 in the journal Proceedings of the National Academy of Sciences:

-- "We aren't the same as people even 1,000 or 2,000 years ago," he says, which may explain, for example, part of the difference between Viking invaders and their peaceful Swedish descendants. "The dogma has been t…

Child Studies May Ease Fears on Misbehavior

November 12, 2007

By BENEDICT CAREY Educators and psychologists have long feared that children entering school with behavior problems were doomed to fall behind in the upper grades. But two new studies suggest that those fears are exaggerated. One concluded that kindergartners who are identified as troubled do as well academically as their peers in elementary school. The other found that children with attention deficit disorders suffer primarily from a delay in brain development, not from a deficit or flaw. Experts say the findings of the two studies, being published Tuesday in separate journals, could change the way scientists, teachers and parents understand and manage children who are disruptive or emotionally withdrawn in the early years of school. The studies might even prompt a reassessment of the possible causes of disruptive behavior in some children. “I think these may become landmark findings, forcing us to ask whether these acting-out kinds of problems are secondary to the in…

Taming Baby Rage: Why Are Some Kids So Angry?

New research indicates babies are born with violent tendencies that most learn to control

It is not the cartoons that make your kids smack playmates or violently grab their toys but, rather, a lack of social skills, according to new research. "It's a natural behavior and it's surprising that the idea that children and adolescents learn aggression from the media is still relevant," says Richard Tremblay, a professor of pediatrics, psychiatry and psychology at the University of Montreal, who has spent more than two decades tracking 35,000 Canadian children (from age five months through their 20s) in search of the roots of physical aggression. "Clearly youth were violent before television appeared." Tremblay's previous results have suggested that children on average reach a peak of violent behavior (biting, scratching, screaming, hitting…) around 18 months Image: © ISTOCKPHOTO/TYLER STALMAN FAILURE TO UNLEARN: A Canadian researcher suggests t…

The Culture of Males and Females

August 20, 2007

New York Times

Is There Anything Good About Men? And Other Tricky Questions

By John Tierney

What percentage of your ancestors were men?

No, it’s not 50 percent, as I’ll explain shortly. But first let me credit the
source, Roy F. Baumeister, who answered that question – and a lot of other ones
– in an address on Friday at the annual convention of the American Psychological
Association in San Francisco. I recommend reading the whole speech: "Is There
Anything Good About Men?"

As you might expect, he did find something good to say about men, but the
speech wasn’t an apologia for the gender, or a whine about the abuse heaped on
men. Rather, it was a shrewd and provocative look at the motivational
differences between men and women – and at some of the topics (like the gender
imbalance on science faculties) that got Larry Summers in so much trouble at
Harvard. Dr. Baumeister, a prominent social psychologist who teaches at Florida
State University, began by asking gen…

More research points to rapid evolution

Time changes modern human's face

By Rebecca Morelle
BBC News science reporter
Researchers have found that the shape of the human skull has changed significantly over the past 650 years. Modern people possess less prominent features but higher foreheads than our medieval ancestors. Writing in the British Dental Journal, the team took careful measurements of groups of skulls spanning across 30 generations. The scientists said the differences between past and present skull shapes were "striking". Plague victims The team used radiographic films of skulls to record extensive measurements taken by a computer.They looked at 30 skulls dating from the mid-14th Century. They had come from the unlucky victims of the plague. The skulls had been excavated from plague pits in the 1980s in London. Another 54 skulls examined by the team were recovered from the wreck of the Mary Rose which sank off the south coast of England in 1545. All the skulls were compared with 31 recent …

Division of genders really is color coded

By Leigh DaytonAugust 21, 2007 02:00am
IT'S official. Blue is the most popular colour and women really do prefer pink, and reddish shades of blue like lilac and purple. And the preference isn't just a result of social stereotypes, pushing pink on girls and blue on boys. It's innate and occurs across cultures, claim British researchers who studied the colour preferences of 208 young adults: 171 Britons and 37 mainland Chinese. "Although we expected to find sex differences, we were surprised at how robust they were, given the simplicity of ourtest," said visual neuroscientist Anya Hurlbert of Newcastle University at Newcastle upon Tyne. Along with psychologist Yazhu Ling, Professor Hurlbert asked volunteers to select, as quickly as possible, their preferred colour from each of a series of paired, coloured rectangles. They reported yesterday in the journal Current Biology that the most popular colour by far was blue. "On top of that, females have a prefe…

Temperamental differences by race

Excerpted from: Solving The African IQ Conundrum : "Winning Personality" Masks Low Scores
By J. Philippe Rushton
August 12, 2004

Over a century ago, Sir Francis Galton initiated research into individual and race differences in intelligence and temperament. He was the first to propose the study of human twins and of selective breeding in animals to disentangle the effects of heredity and environment. And it was Galton—who spent several years exploring in what is now Namibia as a young man—who first contrasted the talkative impulsivity of Africans with the taciturn reserve of American Indians, and the placidity of the Chinese.

Galton further noted that these temperament differences persisted irrespective of climate (from the frozen north through the torrid equator), and religion, language, or political system (whether self-ruled or governed by the Spanish, Portuguese, English or French).

Anticipating later studies of transracial adoptio…

Evolution Occurs in the Blink of an Eye

By Jeanna Bryner, LiveScience Staff Writer

A population of butterflies has evolved in a flash on a South Pacific
island to fend off a deadly parasite.

The proportion of male Blue Moon butterflies dropped to a precarious 1
percent as the parasite targeted males. Then, within the span of a mere 10
generations, the males evolved an immunity that allowed their population
share to soar to nearly 40 percent-all in less than a year.

"We usually think of natural selection as acting slowly, over hundreds or
thousands of years," said study team member Gregory Hurst, an evolutionary
geneticist at the University College London. "But the example in this study
happened in a blink of the eye, in terms of evolutionary time."

The scientists think the males developed genes that hold a male-killing
microbial parasite, called Wolbachia, at bay.

The results, detailed in the July 13 issue of the journal Science,
illustrate the power of positive natural selection on "suppressor"…

Study finds wives have greater power in marriage problem-solving behavior

Men may still have more power in the workplace, but apparently women really are "the boss" at home. That's according to a new study by a team of Iowa State University researchers.
The study of 72 married couples from Iowa found that wives, on average, exhibit greater situational power -- in the form of domineering and dominant behaviors -- than their husbands during problem-solving discussions, regardless of who raised the topic. All of the couples in the sample were relatively happy in their marriages, with none in counseling at the time of the study.

Associate Professor of Psychology David Vogel and Assistant Professor of Human Development and Family Studies Megan Murphy led the research. The ISU research team also included Associate Professor of Human Development and Family Studies Ronald Werner-Wilson, Professor of Psychology Carolyn Cutrona -- who is director of the Institute for Social and Behavioral Research at Iowa State -- and Joann Seeman, a graduate …

Humans Have Spread Globally, and Evolved Locally

The New York Times
June 26, 2007


Historians often assume that they need pay no attention to human evolution because the process ground to a halt in the distant past. That assumption is looking less and less secure in light of new findings based on decoding human DNA.

People have continued to evolve since leaving the ancestral homeland in northeastern Africa some 50,000 years ago, both through the random process known as genetic drift and through natural selection. The genome bears many fingerprints in places where natural selection has recently remolded the human clay, researchers have found, as people in the various continents adapted to new diseases, climates, diets and, perhaps, behavioral demands.

A striking feature of many of these changes is that they are local. The genes under selective pressure found in one continent-based population or race are mostly different from those that occur in the others.These genes so far make up a small fraction of all human genes.

A not…

Being Treated As Oldest Linked to IQ

(AP) -- Children at the top of the pecking order - either by birth or because their older siblings died - score higher on IQ tests than their younger brothers or sisters. The question of whether firstborn and only children are really smarter than those who come along later has been hotly debated for more than a century. Norwegian researchers now report that it isn't a matter of being born first, but growing up the senior child, that seems to result in the higher IQ scores.
Petter Kristensen and Tor Bjerkedal report their findings in Friday's issue of the journal Science.

It's a matter of what they call social rank in the family - the highest scores were racked by the senior child - the first born or, if the first born had died in infancy, the next oldest.

Kristensen, of Norway's National Institute of Occupational Health, and Bjerkedal, of the Norwegian Armed Forces Medical Services, studied the IQ test results of 241,310 Norwegians drafted into the armed force…

Brains Reflect Sex Differences

Science Daily — When male primates tussle and females develop their social skills it leaves a permanent mark – on their brains. According to research published in the online open access journal BMC Biology, brain structures have developed due to different pressures on males and females to keep up with social or competitive demands.

An international research team consisting of Patrik Lindenfors, Charles Nunn and Robert Barton examined data on primate brain structures in relation to traits important for male competition, such as greater body mass and larger canine teeth. The researchers also took into account the typical group size of each sex for individual primate species in order to assess sex-specific sociality - the tendency to associate with others and form social groups. The researchers then studied the differences between 21 primate species, which included chimpanzees, gorillas, and rhesus monkeys, using statistical techniques that incorporate evolutionary processes.

The authors f…

Addict brain 'designed for drugs'

Physical differences in the brain may increase the chances of a person choosing to take drugs, say Cambridge University scientists.

A study of rats showed variations in brain structure pre-dated their first exposure to narcotics, and made them more likely to opt for cocaine.

Writing in Science, the team say genes may affect these differences in humans.

Treatments to reduce their effect may be found - but a test of vulnerability to drugs is unlikely, they add.

Up to 500,000 people are currently addicted to Class A drugs such as cocaine, heroin and amphetamines, according to government figures.

One of the most important questions in the science of addiction surrounds the origin of differences noticed in the brains of human drug users.

While these differences are thought to be important in the way humans respond to drugs, it is difficult to prove whether they are a part of the natural brain chemistry of that individual, or have developed as a result of taking the drugs themselves.

To unr…

Shyness and Genes

A related study on resilience and genes posted on on this weblog May 7th (see also the Dec. 2nd post on antisocial behavior) turns this relationship on its head. It too notes that a genetic predisposition to certain behavior--in this earlier report, the ability to tough it out in the face of adverse circumstances--is triggered or not by environmental influences. In recent years, biological science has proposed a new paradigm. The latest research shows that resilience can best be understood as an interplay between particular genes and environment — GxE, in the lingo of the field. Researchers are discovering that a particular variation of a gene can help promote resilience in the people who have it, acting as a buffer against the ruinous effects of adversity. In the absence of an adverse environment, however, the gene doesn't express itself in this way. It drops out of the psychological picture. "We now have well-replicated findings showing that genes play a major role in influ…

Changes in Latitude ~ Changes in Attitude

From Steve Sailer:

Why is Respectable Opinon so sure that there isn't the slightest kernel of truth in Afrocentrist rantings about African Sun People and European Ice People? I'm not saying that Dr. Lionel Jeffries knows anything about biochemistry, but I am saying that there seems to be some sort of correlation between gloomy, cold weather and gloomy, cold personalities, just like there is between sunny, warm weather and sunny, warm personalities. And that if the chemical at work is not melanin, it's worth finding out what it is.

Personally, I don't know whether being tanned keeps me happy (as "melanin science" would suggest), but getting tanned sure lifts my mood for at least a few hours. What is the biochemical mechanism behind this?

Further, there seems to be a very rough but real relationship between latitude and attitude, with hotter climes correlating with hotter moods. This is a consistent theme through most literature at least since Shakespeare, w…