Saturday, November 26, 2011
After watching videos of adults cradling and striking balloons, male but not female 6-to-9-month-olds began to hit balloons more often. This suggests that males have an innate fascination with "propulsive movement," researchers say.
After getting acquainted with a toy balloon, 45 children—too young to label themselves by gender—watched split-screen video clips: On one side, a man or woman cradled a balloon; on the other, the same man or woman hit the balloon.
Boys tended to watch the people striking balloons more than girls did. After watching, they batted their own balloons more than before, while girls didn't change behavior.
There were no sex differences in how children handled the balloons before the videos started and no evidence that the parents of boys had promoted this play style.
If an innate fascination with propulsive motion exists, it may explain why boys gravitate to toys that move, such as trucks, without parental encouragement, researchers said.
"Male More Than Female Infants Imitate Propulsive Motion," Joyce F. Benenson, Robert Tennyson and Richard W. Wrangham, Cognition (November)
Tuesday, October 25, 2011
Friday, October 07, 2011
Wednesday, August 10, 2011
Criminal Minds Are Different From Yours, Brain Scans Reveal
by Clara Moskowitz, LiveScience Senior Writer
Date: 04 March 2011http://www.livescience.com/13083-criminals-brain-neuroscience-ethics.html
The latest neuroscience research is presenting intriguing evidence that the brains of certain kinds of criminals are different from those of the rest of the population.
While these findings could improve our understanding of criminal behavior, they also raise moral quandaries about whether and how society should use this knowledge to combat crime.
The criminal mind
In one recent study, scientists examined 21 people with antisocial personality disorder – a condition that characterizes many convicted criminals. Those with the disorder "typically have no regard for right and wrong. They may often violate the law and the rights of others," according to the Mayo Clinic.
Brain scans of the antisocial people, compared with a control group of individuals without any mental disorders, showed on average an 18-percent reduction in the volume of the brain's middle frontal gyrus, and a 9 percent reduction in the volume of the orbital frontal gyrus – two sections in the brain's frontal lobe.
Another brain study, published in the September 2009 Archives of General Psychiatry, compared 27 psychopaths — people with severe antisocial personality disorder — to 32 non-psychopaths. In the psychopaths, the researchers observed deformations in another part of the brain called the amygdala, with the psychopaths showing a thinning of the outer layer of that region called the cortex and, on average, an 18-percent volume reduction in this part of brain.
"The amygdala is the seat of emotion. Psychopaths lack emotion. They lack empathy, remorse, guilt," said research team member Adrian Raine, chair of the Department of Criminology at the University of Pennsylvania, at the annual meeting of the American Association for the Advancement of Science in Washington, D.C., last month.
In addition to brain differences, people who end up beingconvicted for crimes often show behavioral differences compared with the rest of the population. One long-term study that Raine participated in followed 1,795 children born in two towns from ages 3 to 23. The study measured many aspects of these individuals' growth and development, and found that 137 became criminal offenders.
One test on the participants at age 3 measured their response to fear – called fear conditioning – by associating a stimulus, such as a tone, with a punishment like an electric shock, and then measuring people's involuntary physical responses through the skin upon hearing the tone.
In this case, the researchers found a distinct lack of fear conditioning in the 3-year-olds who would later become criminals. These findings were published in the January 2010 issue of the American Journal of Psychiatry.
Neurological base of crime
Overall, these studies and many more like them paint a picture of significant biological differences between people who commit serious crimes and people who do not. While not all people with antisocial personality disorder — or even all psychopaths — end up breaking the law, and not all criminals meet the criteria for these disorders, there is a marked correlation.
"There is a neuroscience basis in part to the cause of crime," Raine said.
What's more, as the study of 3-year-olds and other research have shown, many of thesebrain differences can be measured early on in life, long before a person might develop into actual psychopathic tendencies or commit a crime.
Criminologist Nathalie Fontaine of Indiana University studies the tendency toward being callous and unemotional (CU) in children between 7 and 12 years old. Children with these traits have been shown to have a higher risk of becoming psychopaths as adults.
"We're not suggesting that some children are psychopaths, but CU traits can be used to identify a subgroup of children who are at risk," Fontaine said.
Yet her research showed that these traits aren't fixed, and can change in children as they grow. So if psychologists identify children with these risk factors early on, it may not be too late.
"We can still help them," Fontaine said. "We can implement intervention to support and help children and their families, and we should."
Neuroscientists' understanding of the plasticity, or flexibility, of the brain called neurogenesis supports the idea that many of these brain differences are not fixed. [10 Things You Didn't Know About the Brain]
"Brain research is showing us that neurogenesis can occur even into adulthood," said psychologist Patricia Brennan of Emory University in Atlanta. "Biology isn’t destiny. There are many, many places you can intervene along that developmental pathway to change what's happening in these children."
Furthermore, criminal behavior is certainly not a fixed behavior.
Psychologist Dustin Pardini of the University of Pittsburgh Medical Center found that about four out of five kids who are delinquents as children do not continue to offend in adulthood.
Pardini has been researching the potential brain differences between people with a past criminal record who have stopped committing crimes, and those who continue criminal behavior. While both groups showed brain differences compared with non-criminals in the study, Pardini and his colleagues uncovered few brain differences between chronic offenders and so-called remitting offenders.
"Both groups showed similar results," Pardini said. "None of these brain regions distinguish chronic and remitting offenders."
Yet even the idea of intervening to help children at risk of becoming criminals is ethically fraught.
"Do we put children in compulsory treatment when we've uncovered the risk factors?" asked Raine. "Well, who decides that? Will the state mandate compulsory residential treatment?"
What if surgical treatment methods are advanced, and there is an option to operate on children or adults with these brain risk factors? Many experts are extremely hesitant to advocate such an invasive and risky brain intervention — especially in children and in individuals who have not yet committed any crime.
Yet psychologists say such solutions are not the only way to intervene.
"You don’t have to do direct brain surgery to change the way the brain functions," Brennan said. "You can do social interventions to change that."
Fontaine's studies, for example, suggest that kids who display callous and unemotional traits don't respond as well to traditional parenting and punishment methods such as time-outs. Instead of punishing bad behavior, programs that emphasize rewarding good behavior with positive reinforcement seem to work better.
Raine and his colleagues are also testing whether children who take supplemental pills of omega-3 fatty acids — also known as fish oil — can show improvement. Because this nutrient is thought to be used in cell growth, neuroscientists suspect it can help brain cells grow larger, increase the size of axons (the part of neurons that conducts electrical impulses), and regulate brain cell function.
"We are brain scanning children before and after treatment with omega-3," Raine said. "We are studying kids to see if it can reduce aggressive behavior and improve impaired brain areas. It's a biological treatment, but it's a relatively benign treatment that most people would accept."
'Slippery slope to Armageddon'
The field of neurocriminology also raises other philosophical quandaries, such as the question of whether revealing the role of brain abnormalities in crime reduces a person's responsibility for his or her own actions.
"Psychopaths know right and wrong cognitively, but don't have a feeling for what's right and wrong," Raine said. "Did they ask to have an amygdala that wasn't as well functioning as other individuals'? Should we be punishing psychopaths as harshly as we do?"
Because the brain of a psychopath is compromised, Raine said, one could argue that they don't have full responsibility for their actions. That — in effect — it's not their fault.
In fact, that reasoning has been argued in a court of law. Raine recounted a case he consulted on, of a man named Herbert Weinstein who had killed his wife. Brain scanssubsequently revealed a large cyst in the frontal cortex of Weinstein's brain, showing that his cognitive abilities were significantly compromised.
The scans were used to strike a plea bargain in which Weinstein's sentence was reduced to only 11 years in prison.
"Imaging was used to reduce his culpability, to reduce his responsibility," Raine said. "Yet is that not a slippery slope to Armageddon where there's no responsibility in society?"
Wednesday, June 22, 2011
Genetic Basis for Crime: A New Look
Published: June 19, 2011
It was less than 20 years ago that the National Institutes of Health abruptly withdrew funds for a conference on genetics and crime after outraged complaints that the idea smacked of eugenics. The president of the Association of Black Psychologists at the time declared that such research was in itself “a blatant form of stereotyping and racism.”
The turnabout will be evident on Monday at the annualNational Institute of Justice conference in Arlington, Va. On the opening day criminologists from around the country can attend a panel on creating databases for information about DNA and “new genetic markers” that forensic scientists are discovering.
“Throughout the past 30 or 40 years most criminologists couldn’t say the word ‘genetics’ without spitting,” Terrie E. Moffitt, a behavioral scientist at Duke University, said. “Today the most compelling modern theories of crime and violence weave social and biological themes together.”
Researchers estimate that at least 100 studies have shown that genes play a role in crimes. “Very good methodological advances have meant that a wide range of genetic work is being done,” said John H. Laub, the director of the justice institute, who won the Stockholm Prize in Criminology last week. He and others take pains to emphasize, however, that genes are ruled by the environment, which can either mute or aggravate violent impulses. Many people with the same genetic tendency for aggressiveness will never throw a punch, while others without it could be career criminals.
The subject still raises thorny ethical and policy questions. Should a genetic predisposition influence sentencing? Could genetic tests be used to tailor rehabilitation programs to individual criminals? Should adults or children with a biological marker for violence be identified?
Everyone in the field agrees there is no “crime gene.” What most researchers are looking for are inherited traits that are linked to aggression and antisocial behaviors, which may in turn lead to violent crime. Don’t expect anyone to discover how someone’s DNA might identify the next Bernard L. Madoff. ...
One gene that has been linked to violence regulates the production of the monoamine oxidase A enzyme, which controls the amount of serotonin in the brain. People with a version of the gene that produces less of the enzyme tend to be significantly more impulsive and aggressive, but, as Ms. Moffitt and her colleague (and husband) Avshalom Caspi discovered, the effect of the gene is triggered by stressful experiences.
Steven Pinker, a professor of psychology at Harvard whose forthcoming book, “The Better Angels of Our Nature,” argues that humans have become less violent over the millenniums, suggests that the way to think about genetics and crime is to start with human nature and then look at what causes the switch for a particular trait to be flipped on or off.
“It is not a claim about how John and Bill differ, but about how every male is the same,” he said. Understanding the genetics of violence can “tell you what aspect of the environment you should look at.”
He mentioned one of the biggest risk factors leading to crime: remaining single instead of getting married, a link uncovered by Mr. Laub and Robert J. Sampson, a Harvard sociologist who was a co-winner of the Stockholm Prize. Marriage may serve as a switch that directs male energies toward investing in a family rather than competing with other males, Mr. Pinker said.
Kevin Beaver, an associate professor at Florida State University’s College of Criminology and Criminal Justice, said genetics may account for, say, half of a person’s aggressive behavior, but that 50 percent comprises hundreds or thousands of genes that express themselves differently depending on the environment.
He has tried to measure which circumstances — having delinquent friends, living in a disadvantaged neighborhood — influence whether a predisposition to violence surfaces. After studying twins and siblings, he came up with an astonishing result: In boys not exposed to the risk factors, genetics played no role in any of their violent behavior. The positive environment had prevented the genetic switches — to use Mr. Pinker’s word — that affect aggression from being turned on. In boys with eight or more risk factors, however, genes explained 80 percent of their violence. Their switches had been flipped.
A rash of new research has focused on self-control as well as callousness and a lack of empathy, traits regularly implicated in the decision to commit a crime. Like other personality traits, these are believed to have environmental and genetic components, although the degree of heritability is debated.
In findings from a long-term study of 1,000 babies born in 1972 in a New Zealand town, Ms. Moffitt and her colleagues recently reported that the less self-control a child displayed at 3 years of age, the more likely he or she was to commit a crime more than 30 years later. Forty-three percent of the children who scored in the lowest fifth on self-control were later convicted of a crime, she said, versus 13 percent of those who scored in the highest fifth.
But a predisposition is not destiny. “Knowing something is inherited does not IN ANY WAY tell us anything about whether changing the environment will improve it,” Ms. Moffitt wrote in an e-mail. “For example, self-control is a lot like height, it varies widely in the human population, and it is highly heritable, but if an effective intervention such as better nutrition is applied to the whole population, then everyone gets taller than the last generation.”
Criminologists and sociologists have been much more skittish about genetic causes of crime than psychologists. In 2008 a survey conducted by John Paul Wright, who heads graduate programs at the University of Cincinnati’s School of Criminal Justice, discovered that “not a single study on the biology-crime link has been published in dissertation form in the last 20 years” from a criminal justice Ph.D. program, aside from two dissertations he had personally overseen (one of which was Mr. Beaver’s). He also noted that the top four journals in the field had scarcely published any biological research in the past two decades.
Mr. Wright said he now thinks “in criminology the tide is turning, especially among younger scholars.”
But recent work has tended to air outside the main criminology forums. Mr. Beaver, for example, published a paper in Biological Psychiatry in February that concluded that adoptees whose biological parents had broken the law “were significantly more likely to be arrested, sentenced to probation, incarcerated, and arrested multiple times when compared with adoptees whose biological parents had not been arrested.”
At the American Association for the Advancement of Science’s meeting in February,Adrian Raine, chairman of the criminology department at the University of Pennsylvania and a pioneer in the field, presented a paper showing how variations in the parts of a toddler’s brain that regulate emotions — believed to be a product of genes and environment — turned out to be a good predictor of criminal behavior later in life.
Mr. Sampson, who planned to attend the opening day of the justice institute conference, said that “sociology has nothing to fear from genetic research,” but he maintained that the most interesting questions about crime, like why some communities have a higher crime rate than others, are not traceable at all to genetics. “The more sophisticated the genetic research, the more it will show the importance of social context,” he said.