Links for Keyword: Aggression

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by Virginia Morell As any dog owner knows, dogs pay close attention to each other's growls—and with good reason. A new study reveals that dogs can tell another canine's size simply by listening to its growl. The size information is so accurate that a dog hearing a growl can match the sound to a photograph of the growler—a complex cognitive talent previously seen only in primates. In a previous study, Péter Pongrácz, an ethologist at Eötvös Loránd University in Hungary, and colleagues showed that dogs use a specific growl ("this bone is mine") when guarding a tasty bone. The growl always causes a listening dog to stop in its tracks. In their new study, the scientists tested the responses of dogs seated next to their owners, so that the animals felt comfortable in the lab. Twenty-four of the 96 dogs were shown images of two dogs projected onto a screen in front of them (see picture). One image showed a small dog less than 52 centimeters tall; the other image was of the same dog but projected as being taller than 60 cm (a 30% increase in size). The other dogs were shown control images, either of large and small triangles or of the silhouettes of large and small cats. The researchers then played recorded food-guarding growls—from either a large or a small dog—on a speaker placed between the two projected images. The scientists filmed the dogs, recording where the canines looked as they listened to the growls. © 2010 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Our Divided Brain
Link ID: 14788 - Posted: 12.16.2010

by Debora MacKenzie It's been called the "warrior gene" – a mutation that seems to make people more aggressive. Now researchers report that people with this gene may not be aggressive, just better at spotting their own interests. Previous research has found that people with MAOA-L, a gene that controls signalling chemicals in the brain, can be more aggressive. But there is enormous controversy about this, as the gene's effects seem to vary with people's backgrounds. Cary Frydman and colleagues at the California Institute of Technology in Pasadena have now found that people with MAOA-L "just make better choices", says Frydman. "This isn't the same as aggression." Variants of the gene MAOA produce less or more of an enzyme that degrades several signalling chemicals, known as neurotransmitters. People with MAOA-L, which results in less of the enzyme, sometimes show more aggression or impulsivity – but not always. To try to dissect these differences, Frydman gave 83 male volunteers 140 hypothetical choices. With 3 minutes for each choice, the men had to decide whether they preferred a sure thing, say being given $2, or a risky option, for example a 50:50 chance of gaining $10 or losing $5. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 14: Attention and Consciousness
Link ID: 14755 - Posted: 12.09.2010

By Emily Anthes In the wake of several tragedies that have made bullying a high-profile issue, it’s becoming clear that harassment by one’s peers is something more than just a rite of passage. Bullied kids are more likely to be depressed, anxious, and suicidal. They struggle in school — when they decide to show up at all. They are more likely to carry weapons, get in fights, and use drugs. But when it comes to the actual harm bullying does, the picture grows murkier. The psychological torment that victims feel is real. But perhaps because many of us have experienced this sort of schoolyard cruelty and lived to tell the tale, peer harassment is still commonly written off as a “soft” form of abuse — one that leaves no obvious injuries and that most victims simply get over. It’s easy to imagine that, painful as bullying can be, all it hurts is our feelings. A new wave of research into bullying’s effects, however, is now suggesting something more than that — that in fact, bullying can leave an indelible imprint on a teen’s brain at a time when it is still growing and developing. Being ostracized by one’s peers, it seems, can throw adolescent hormones even further out of whack, lead to reduced connectivity in the brain, and even sabotage the growth of new neurons. These neurological scars, it turns out, closely resemble those borne by children who are physically and sexually abused in early childhood. Neuroscientists now know that the human brain continues to grow and change long after the first few years of life. By revealing the internal physiological damage that bullying can do, researchers are recasting it not as merely an unfortunate rite of passage but as a serious form of childhood trauma. © 2010 NY Times Co.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 14739 - Posted: 12.04.2010

By Susan Milius Not to reopen any emotional scars from Thanksgiving dinner, but an unusual study of an animal social network suggests that ending up as the butt of unfriendly interactions could be in part inherited. The study, in yellow-bellied marmots, gives the first look beyond people at what facets of social relationships might have genetic components, says coauthor Daniel Blumstein of UCLA. It’s receiving incoming social attention, particularly in grouchy interactions, that showed a small but intriguing genetic influence, Blumstein says. Aspects of initiating interactions in a network, whether to dish out snubs or snuggles, showed no evidence of heritability, according to the paper posted online November 29 in the Proceedings of the National Academy of Sciences. “I am completely blown away by this paper,” says James Fowler, professor of medical genetics and political science at the University of California, San Diego. In human networks, he and his colleagues have found the marmotlike pattern of heritability in aspects of received social ties but not in initiated ones. Fowler had suspected that the asymmetry in people came from a quirk of limiting the number of friends in the study. Marmots didn’t have that limitation though, he says, “so the idea that there may be something systematic here between species is extremely interesting.” Marmots don’t have Facebook yet, but animals living among clusters of burrows in Colorado do interact enough for observers to plot networks with each marmot as a node. An exchange might be friendly, such as a marmot grooming a neighbor or settling down tranquilly nearby. Or a social interaction might go sour, with one marmot nipping or chasing another. © Society for Science & the Public 2000 - 2010

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 14716 - Posted: 11.30.2010

By SINDYA N. BHANOO The human tendency to form close bonds with people other than kin may have primal roots. Researchers from Germany report in the journal Current Biology that male macaques exhibit a social bonding behavior similar to human friendship. A macaque in Thailand. Scientists say males of the species develop bonds like human friendship. Macaque monkeys live in groups of 50 to 60, but “every male in the group has a few other males he interacts with more than others,” said Oliver Schülke, the study’s lead author and an evolutionary biologist at the University of Göttingen. Dr. Schülke and his colleagues studied male Assamese macaques in Thailand over a period of five years and monitored their behavior. Macaques that spent a lot of time within 1.5 meters of each other were considered friends, since it is easy to attack another macaque at this distance. Males that groomed each other’s bodies frequently and for excessive periods of time were also considered friends. Often, they groomed areas that an individual could groom himself. “The grooming seems to work to foster these bonds,” Dr. Schülke said. “The hygiene aspect was only one part of it.” The bonds can lead to the forming of coalitions, where a group of males might fight another male to improve rank and social status, the researchers found. Copyright 2010 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 8: Hormones and Sex
Link ID: 14703 - Posted: 11.23.2010

WHAT makes people psychopaths is not an idle question. Prisons are packed with them. So, according to some, are boardrooms. The combination of a propensity for impulsive risk-taking with a lack of guilt and shame (the two main characteristics of psychopathy) may lead, according to circumstances, to a criminal career or a business one. That has provoked a debate about whether the phenomenon is an aberration, or whether natural selection favours it, at least when it is rare in a population. The boardroom, after all, is a desirable place to be—and before the invention of prisons, even crime might often have paid. To shed some light on this question Elsa Ermer and Kent Kiehl of the University of New Mexico, Albuquerque, decided to probe psychopaths’ moral sensibilities and their attitude to risk a little further. Their results do not prove that psychopathy is adaptive, but they do suggest that it depends on specific mechanisms (or, rather, a specific lack of them). Such specificity is often the result of evolution. Past work has established that psychopaths have normal levels of intelligence (they are only rarely Hannibal Lecter-like geniuses). Nor does their lack of guilt and shame seem to spring from a deficient grasp of right and wrong. Ask a psychopath what he is supposed to do in a particular situation, and he can usually give you what non-psychopaths would regard as the correct answer. It is just that he does not seem bound to act on that knowledge. © The Economist Newspaper Limited 2010.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 14685 - Posted: 11.16.2010

By Dave Lee BBC World Service Young offenders are more likely to have suffered a brain injury compared with the rest of society, a study suggests. A survey of 197 young male offenders found about half reported having had a childhood brain injury - three times higher than in non-offenders. Multiple head injuries were linked with carrying out more violent crimes, says the University of Exeter team. Better assessment of injuries could help prevent re-offending, they add. The researchers asked 197 offenders aged 11 to 19 years about their past medical history, convicted crimes, mental health and drug use. They considered the effects of traumatic brain injury alongside other factors such as deprivation and lack of life opportunities to determine if a childhood brain injury contributed to future acts of criminal behaviour. The study, published in the journal Neuropsychological Rehabilitation, found that while a brain injury alone is unlikely to increase a child's chances of criminal activity, it could play a factor in those already susceptible to crime, and may increase the chance of repeat offences. "The associations between brain injuries and crime are very problematic," explained Huw Williams, associate professor of clinical neuropsychology at the University of Exeter, on Radio 4's All in the Mind. "It may not be causal in the sense of increasing the chances of crime, but it may well be a factor in terms of re-offending." BBC © MMX

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Our Divided Brain
Link ID: 14654 - Posted: 11.11.2010

Repeated viewing of violent scenes in films, television or video games could make teenagers behave more aggressively, US research suggests. The National Institutes of Health study of 22 boys aged 14 to 17 found that showing dozens of violent clips appeared to blunt brain responses. Dr Jordan Grafman said it might make aggression feel more "acceptable". However, a UK expert said the reasons behind violence were too complex to be explained by laboratory research. The effect of violent imagery on young people has been debated from the early days of television, and, more recently, that debate has expanded to include video games. Various studies have suggested that exposure appears to have an effect on the way that the brain processes emotional responses, yet it is unclear whether this can have a direct impact on behaviour. The US study, published in the journal Social Cognitive & Affective Neuroscience, involved 60 violent scenes from videos being collated, mostly involving street brawling and fist fights. The violence was ranked "low", "mild" or "moderate", and there were no "extreme" scenes. BBC © MMX

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 14567 - Posted: 10.19.2010

By NOAH SNYDER-MACKLER In baboons, a new mother will rarely find herself alone. She will be hounded constantly by other, higher-ranking females who want to look, touch and sometimes steal the infant. But female geladas do not usually show much interest in others’ babies. A newborn gelada never leaves its mother’s chest in the first month, and it spends a majority of its time attached to her until it is about six months old. Mama geladas are extremely protective of their infants, and with good reason. Infanticide appears to be prevalent, especially following a change in dominant male (known as a “takeover”). Male infanticide — the killing of infants by males — is the most common form of infanticide in primates. It has been argued that this is beneficial for newly dominant males because the females will come into estrus sooner, meaning they can produce the new dominant male’s offspring sooner, rather than wait until the former dominant male’s offspring are weaned. There are only a few observed cases of male infanticide in geladas, but our project has found plenty of evidence suggesting that it is common in our study population. I have observed the protectiveness of new gelada mothers. Even though I am not a newly dominant male, nor do I pose a threat, if a curious infant gets too close to me while I am doing behavioral observations, the mother will sprint over, grab her infant and threaten me by flashing her bright pink eyelids. This is when I need to back away. It’s the same response a female will give to another gelada if she perceives that her child is unsafe. Copyright 2010 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 14531 - Posted: 10.07.2010

People who are aggressive may be at higher risk for heart attack or stroke, a new study suggests. The study of 5,614 Italians in Sardinia found that those who scored high for antagonistic traits like competitiveness and aggression on a standard personality test had more thickening of their neck arteries compared with those who were more agreeable. The thickness of this carotid artery is considered a risk factor for heart attack and stroke, researchers said in Monday's online issue of the journal Hypertension: Journal of the American Heart Association. "People who tend to be competitive and more willing to fight for their own self-interest have thicker arterial walls, which is a risk factor for cardiovascular disease," Angelina Sutin, the study's lead author and a postdoctoral fellow with the U.S. National Institute on Aging in Baltimore, Md., said in a news release. "Agreeable people tend to be trusting, straightforward and show concern for others while people who score high on antagonism tend to be distrustful, skeptical and at the extreme, cynical, manipulative, self-centered, arrogant and quick to express anger," she added. When researchers followed up with study participants three years after the initial tests, they found they found the link between artery thickening and antagonism had persisted. © CBC 2010

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 14368 - Posted: 08.17.2010

by Kristen Minogue "Free-range" chickens are the gold standard for consumers interested in humanely raised livestock. But for most chickens, the wide-open spaces of a free-range poultry farm aren't nearly as idyllic as they sound. The birds often peck at each other's feathers, causing painful scars, bleeding, and even death. Now, researchers have developed a mathematical model that may help farmers stop the pecking before it starts. It's unclear why chickens like to bite the feathers off their neighbors. According to bird-welfare researcher Bas Rodenburg of Wageningen University in the Netherlands, the best explanation is that they've evolved to peck for food in the wild, and this need is not satisfied on the farm. "Instead of pecking at the floor, for instance, they start pecking at each other's feathers," Rodenburg says. Right now, the only way for free-range farmers to prevent the behavior is beak trimming, a euphemism for cutting off the sharp tip of a bird's beak with a hot blade or directing infrared rays into its inner tissue until the tip falls off a few weeks later. To find a better solution, a team of zoologists and engineers studied video recordings of more than 300,000 hens living on free-range farms in the United Kingdom. The researchers applied a mathematical technique called optical flow modeling, which has been used to study traffic patterns and human crowds, to track how the chickens moved in large groups. The process involved analyzing multiple snapshots of the same 50 to 100 hens taken at different times to find patterns of movement that correlate with chicken-on-chicken violence. © 2010 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 14316 - Posted: 08.03.2010

By Steve Connor, Science Editor Aggressive teenagers with severe behavioural problems may have developed a biological abnormality in their brain, causing them to be aggressive and anti-social, a study has found. Scientists believe they have discovered the first hard evidence showing that conduct disorder in adolescents has a biological basis connected with brain chemistry, rather than being the result of the desire in teenagers to ape their badly-behaved peers. The findings suggest that it may be possible to diagnose a predisposition to conduct disorder in early childhood so that child psychologists could intervene before the behaviour starts to deteriorate. Conduct disorder affects five per cent of teenagers and costs society millions of pounds in terms of remedial education. "Detecting conduct disorder in adolescence may be too late to do anything about it. Early identification of a biological abnormality may be a route to take in terms of early intervention," said Andy Calder of the Medical Research Council's Cognition and Brain Sciences Unit in Cambridge, where the study was carried out. "These are pretty severe kids. They are frequently excluded from school over and over again. Some of them will go into young offenders institutions, so they are not just badly behaved kids," Dr Calder said. "Psychiatrists in the past have not really considered conduct disorder as a medical condition. This is research that's saying that actually it has a biological basis and this is soomething we should consider as a medical issue," he said. ©independent.co.uk

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 14235 - Posted: 07.06.2010

by Barbara Bradley Hagerty Kent Kiehl has studied hundreds of psychopaths. Kiehl is one of the world's leading investigators of psychopathy and a professor at the University of New Mexico. He says he can often see it in their eyes: There's an intensity in their stare, as if they're trying to pick up signals on how to respond. But the eyes are not an element of psychopathy, just a clue. Officially, Kiehl scores their pathology on the Hare Psychopathy Checklist, which measures traits such as the inability to feel empathy or remorse, pathological lying, or impulsivity. "The scores range from zero to 40," Kiehl explains in his sunny office overlooking a golf course. "The average person in the community, a male, will score about 4 or 5. Your average inmate will score about 22. An individual with psychopathy is typically described as 30 or above. Brian scored 38.5 basically. He was in the 99th percentile." "Brian" is Brian Dugan, a man who is serving two life sentences for rape and murder in Chicago. Last July, Dugan pleaded guilty to raping and murdering 10-year-old Jeanine Nicarico in 1983, and he was put on trial to determine whether he should be executed. Kiehl was hired by the defense to do a psychiatric evaluation. On screen, Dugan is dressed in an orange jumpsuit. He seems calm, even normal — until he lifts his hands to take a sip of water and you see the handcuffs. Dugan is smart — his IQ is over 140 — but he admits he has always had shallow emotions. He tells Kiehl that in his quarter century in prison, he believes he's developed a sense of remorse. Copyright 2010 NPR

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 14227 - Posted: 07.03.2010

By Dara Greenwood If your children are like 99 percent of boys and 94 percent of girls, they play video games. And, if they are like 50 percent of boys and 14 percent of girls, they prefer games with “mature” – read: violent -- themes, such as Grand Theft Auto, an urban dystopia of gun fights, car chases, pole dancers and prostitutes, where blood splatters realistically on the “camera lens.” Should you worry whether such a game will warp your children’s minds? A new paper by Cheryl Olson, a public health specialist at Harvard, suggests the answer may be: au contraire. Olson surveyed children’s reported motivations for video game playing and found that their top rated choices were to have fun, compete well with others, and to be challenged. She then elaborates on the psychological benefits such play might afford, describing how video games facilitate self-expression, role play, creative problem-solving, cognitive mastery, positive social interactions and leadership. Sounds more utopian than dystopian, right? If only it were that simple. As laudable as it is to debunk negative stereotypes about non-violent game play, it is less laudable to gloss over the negative effects of violent video games. Olson’s rosy spin on violent video games positions her on one side of a heated academic debate with staggering stakes in policy and industry. (See recent salvos here, here and here.) One contingent warns that violent games reduce empathy and effective anger management skills, and promote aggression. The other contingent rebuts that such research plays into “moral panic,” exaggerates the negative impact and ignores the positive effects of violent game play. Given the sheer popularity of violent video games, their psychological impact is an urgent issue for society, and for the millions of parents whose children dive into virtual worlds for hours every day. Let’s take a closer look at the research in question. © 2010 Scientific American,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 14196 - Posted: 06.24.2010

Boys who have a so-called "warrior gene" are more likely to join gangs and also more likely to be among the most violent members and to use weapons, a new study finds. "While gangs typically have been regarded as a sociological phenomenon, our investigation shows that variants of a specific MAOA gene, known as a 'low-activity 3-repeat allele,' play a significant role," said biosocial criminologist Kevin M. Beaver of Florida State University. In 2006, the controversial warrior gene was implicated in the violence of the indigenous Maori people in New Zealand, a claim that Maori leaders dismissed. Story continues below ↓advertisement | your ad here But it's no surprise that genes would be involved in aggression. Aggression is a primal emotion like many others, experts say, and like cooperation, it is part of human nature, something that's passed down genetically. And almost all mammals are aggressive in some way or another, said Craig Kennedy, professor of special education and pediatrics at Vanderbilt University in Tennessee, whose research last year suggested that humans crave violence just like they do sex, food or drugs. "Previous research has linked low-activity MAOA variants to a wide range of antisocial, even violent, behavior, but our study confirms that these variants can predict gang membership," says Beaver, the Florida State researcher. "Moreover, we found that variants of this gene could distinguish gang members who were markedly more likely to behave violently and use weapons from members who were less likely to do either." © 2009 LiveScience.com.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 12927 - Posted: 06.24.2010

by Sunita Reed You may have seen robotic fish, robotic dogs, and even robotic roaches. But you’ve probably never seen a robotic lizard that does four-legged pushups. Its creator is evolutionary ecologist Terry Ord. Ord’s interest in lizards and other animals began as a child growing up in Australia, where his family spent weekends and holidays on their property in Australia’s bush country. “Amongst the rock outcrops around the house, lizards defended territories with elaborate performances of pushups and other displays,” Ord recalls. “The spectacle evidentially had a lasting impression because I would devote my PhD research to deciphering what exactly it was they were saying to each other.” As a researcher, Ord spent weeks at a time observing the male yellow-chinned anole lizard. He noticed that it defended its territory against other males with two types of displays. One is the subtle headbob. The other display is done with the flap of skin under its chin called a dewlap. When extended, it looks like an inflated bright yellow balloon. These two actions comprise the information-rich message that means, “I’m tough, so back off!” But sometimes the lizards would do exaggerated four-legged pushups before they gave this regular message. Was it just another way of flexing their muscles or was it an alert signal that the mostly silent lizards used to get their neighbor’s attention before “talking”? Ord suspected the latter was the case, and decided that the best way to talk to a lizardwas to be a lizard. Ord was at University of California at Davis and worked with Judy Stamps on this project. He now works at Harvard as well. ©2008 ScienCentral

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 12363 - Posted: 06.24.2010

By HENRY FOUNTAIN Crayfish may be small, but they aren’t stupid. After losing a fight they can remember who beat them, and may use that information to steer clear of another fight against the same opponent. Australian researchers studied fights between males of an aggressive species of freshwater crayfish, Cherax dispar. Like most crayfish, C. dispar fights by locking claws with its opponent and holding on until one creature gives up and slinks away. The crayfish with the stronger claws almost always wins a first fight and, in subsequent fights with the same crayfish, it keeps winning, The loser often slinks away without even fighting. The researchers, Frank Seebacher of the University of Sydney and Robbie S. Wilson of the University of Queensland, wanted to see whether in those subsequent fights the loser just blindly leaped into the fray again or recognized that it was up against a superior opponent. In their experiments, described in Biology Letters, they disabled the claws of the winner of the first fight by supergluing them shut and let the two crayfish go at each other a half-hour later and 24 hours later. Even with its claws disabled, the winner of the first fight kept winning, indicating that the loser somehow remembered that the winner was stronger. Copyright 2007 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 10524 - Posted: 06.24.2010

By JOHN SCHWARTZ and BENEDICT CAREY The video testament that Cho Seung-Hui mailed to NBC during the intermission in his killing spree offers a compelling peek into the troubles that shaped a gunman, experts in forensic psychology say. The clips suggest a person with holes in his soul, who lacked features like the emotional control and empathy for others that keep a lid on the violent impulses anyone might have. But can grainy, YouTube-ish video snippets offer real insight into the nature of Mr. Cho’s mental illness? A solid diagnosis requires time and access to the patient, whose history can be as important as his actions; and most people with mental illness are far more likely to harm themselves than others. There is a universe of possible labels, and the exercise can be an empty one, said Robert Hare, an expert in violent behavior who has been a consultant to the F.B.I. “Diagnoses are ill advised if they are made too quickly,” said Dr. Hare, who created one of the most authoritative models for detecting psychopathy. “After-the-fact explanations of this sort can go in about a thousand different directions.” Experts who have watched the videos say that while the picture may yet change, they did see sentiments and thought that hint at Mr. Cho’s mental landscape. Their opinions coalesce around a handful of conditions with names like “psychotic depression” and “avoidant personality disorder” and “schizophrenia-paranoid type.” Copyright 2007 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 10200 - Posted: 06.24.2010

By NICHOLAS WADE On an animal-breeding farm in Siberia are cages housing two colonies of rats. In one colony, the rats have been bred for tameness in the hope of mimicking the mysterious process by which Neolithic farmers first domesticated an animal still kept today. When a visitor enters the room where the tame rats are kept, they poke their snouts through the bars to be petted. The other colony of rats has been bred from exactly the same stock, but for aggressiveness instead. These animals are ferocious. When a visitor appears, the rats hurl themselves screaming toward their bars. “Imagine the most evil supervillain and the nicest, sweetest cartoon animal, and that’s what these two strains of rat are like,” said Tecumseh Fitch, an animal behavior expert at the University of St. Andrews in Scotland who several years ago visited the rats at the farm, about six miles from Akademgorodok, near the Siberian city of Novosibirsk. Frank Albert, a graduate student at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, is working with both the tame and the hyperaggressive Siberian strains in the hope of understanding the genetic basis of their behavioral differences. “The ferocious rats cannot be handled,” Mr. Albert said. “They will not tolerate it. They go totally crazy if you try to pick them up.” Copyright 2006 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory, Learning, and Development
Link ID: 9174 - Posted: 06.24.2010

Janelle Weaver Pigeons wearing miniature backpacks containing tracking devices have revealed that the birds rapidly shift direction during flight in response to cues from the leading members of their group. "It is the first study demonstrating hierarchical decision-making in a group of free-flying birds," says Tams Vicsek, a biophysicist at Eötvös Lornd University in Budapest who led the study, which is published today in Nature1. The discovery became possible only recently with the introduction of Global Positioning System (GPS) devices that can collect data at a high rate: five times per second. Vicsek's team strapped lightweight GPS devices to individual pigeons and tracked flocks of up to 10 birds during free flights lasting around 12 minutes and 15-kilometre homing flights. In total, the GPS logged 32 hours of data and captured 15 group flights. The researchers couldn't pinpoint individuals' exact positions within a flock, but were able to accurately compare birds' directions of motion. Within flocks, the authors looked first at the behaviour of pairs of birds. For each possible pairing, the team identified a leader — the bird that changed direction first — and a follower, which copied the leader's motion. Followers reacted very quickly, within a fraction of a second. Next, the scientists constructed a network of relationships among birds in the group during each flight. They uncovered a robust pecking order: birds higher up the ranks had more influence over the group's movements, and each individual's level of influence was consistent across specific free and homing flights. © 2010 Nature Publishing Group,

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 13949 - Posted: 06.24.2010