By Felicity Muth If you grew up with brothers or sisters you will know that competition is a key part of childhood. Personally, I experienced competition for food resources (the last bar of chocolate), parental investment (attention) and other more unusual resources (the best colour of lego pieces). As we age, we continue competing, although what we compete for changes. We compete in sports, for partners and for jobs. Like humans, pretty much all other animals will compete in one way or another. Even if they live a solitary life they may be still competing indirectly with others. But, like humans, animals need to choose which battles are worth fighting, and how much effort to put into it. One obvious way of deciding when to bother competing with another is the absolute worth of the thing you’re fighting over. If you and a stranger stumbled across some money in the street, you might fight vigorously for a $100 note, but more half-heartedly for $5 (this is of course an example using some very money-driven and aggressive individuals). However, how much value an individual puts on an item’s worth is going to be somewhat subjective. If you’re poor and starving, you might invest more into fighting for $5 than someone who is not. Thus, most competitions will contain both objective and subjective aspects: the intrinsic worth of an object (large food items are better than small), and the individual’s state when they’re assessing that item. © 2013 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 18225 - Posted: 06.04.2013

By CARL ZIMMER Imagine a wolf catching a Frisbee a dozen times in a row, or leading police officers to a stash of cocaine, or just sleeping peacefully next to you on your couch. It’s a stretch, to say the least. Dogs may have evolved from wolves, but the minds of the two canines are profoundly different. Dog brains, as I wrote last month in The New York Times, have become exquisitely tuned to our own. Scientists are now zeroing in on some of the genes that were crucial to the rewiring of dog brains. Their results are fascinating, and not only because they can help us understand how dogs turned into man’s best friend. They may also teach us something about the evolution of our own brains: Some of the genes that evolved in dogs are the same ones that evolved in us. To trace the change in dog brains, scientists have first had to work out how dog breeds are related to one another, and how they’re all related to wolves. Ya-Ping Zhang, a geneticist at the Chinese Academy of Sciences, has led an international network of scientists who have compared pieces of DNA from different canines. They’ve come to the conclusion that wolves started their transformation into dogs in East Asia. Those early dogs then spread to other parts of the world. Many of the breeds we’re most familiar with, like German shepherds and golden retrievers, emerged only in the past few centuries. © 2013 The New York Times Company

Related chapters from BN: 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: 18166 - Posted: 05.18.2013

By ADRIAN RAINE In studying brain scans of criminals, researchers are discovering tell-tale signs of violent tendencies. WSJ's Jason Bellini speaks with Professor Adrian Raine about his latest discoveries. The scientific study of crime got its start on a cold, gray November morning in 1871, on the east coast of Italy. Cesare Lombroso, a psychiatrist and prison doctor at an asylum for the criminally insane, was performing a routine autopsy on an infamous Calabrian brigand named Giuseppe Villella. Lombroso found an unusual indentation at the base of Villella's skull. From this singular observation, he would go on to become the founding father of modern criminology. Lombroso's controversial theory had two key points: that crime originated in large measure from deformities of the brain and that criminals were an evolutionary throwback to more primitive species. Criminals, he believed, could be identified on the basis of physical characteristics, such as a large jaw and a sloping forehead. Based on his measurements of such traits, Lombroso created an evolutionary hierarchy, with Northern Italians and Jews at the top and Southern Italians (like Villella), along with Bolivians and Peruvians, at the bottom. These beliefs, based partly on pseudoscientific phrenological theories about the shape and size of the human head, flourished throughout Europe in the late 19th and early 20th centuries. Lombroso was Jewish and a celebrated intellectual in his day, but the theory he spawned turned out to be socially and scientifically disastrous, not least by encouraging early-20th-century ideas about which human beings were and were not fit to reproduce—or to live at all. ©2013 Dow Jones & Company, Inc.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 18111 - Posted: 05.04.2013

Regina Nuzzo In a twist that evokes the dystopian science fiction of writer Philip K. Dick, neuroscientists have found a way to predict whether convicted felons are likely to commit crimes again from looking at their brain scans. Convicts showing low activity in a brain region associated with decision-making and action are more likely to be arrested again, and sooner. Kent Kiehl, a neuroscientist at the non-profit Mind Research Network in Albuquerque, New Mexico, and his collaborators studied a group of 96 male prisoners just before their release. The researchers used functional magnetic resonance imaging (fMRI) to scan the prisoners’ brains during computer tasks in which subjects had to make quick decisions and inhibit impulsive reactions. The scans focused on activity in a section of the anterior cingulate cortex (ACC), a small region in the front of the brain involved in motor control and executive functioning. The researchers then followed the ex-convicts for four years to see how they fared. Among the subjects of the study, men who had lower ACC activity during the quick-decision tasks were more likely to be arrested again after getting out of prison, even after the researchers accounted for other risk factors such as age, drug and alcohol abuse and psychopathic traits. Men who were in the lower half of the ACC activity ranking had a 2.6-fold higher rate of rearrest for all crimes and a 4.3-fold higher rate for nonviolent crimes. The results are published today in the Proceedings of the National Academy of Sciences1. © 2013 Nature Publishing Group

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 2: Functional Neuroanatomy: The Cells and Structure of the Nervous System
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 1: Cells and Structures: The Anatomy of the Nervous System
Link ID: 17950 - Posted: 03.26.2013

Changing the channel on what TV children watch could improve their behaviour, but watching too much regular programming may have harmful long-term consequences, new research suggests. In Monday's issue of the journal Pediatrics, researchers reported that preschoolers spent less time watching violent programming when they were randomly assigned to participate in a program that encouraged aggression-filled shows to be replaced with educational or empathy-building viewing compared with a control group. Muppets Bert, left, and Ernie, from the children's program Sesame Street, were created to teach preschoolers that people can be good friends with those who are very different from themselves, which builds empathy. "We demonstrated that an intervention to modify the viewing habits of preschool-aged children can significantly enhance their overall social and emotional competence and that low-income boys may derive the greatest benefit," Dr. Dimitri Christakis of Seattle Children's Research Institute and his co-authors concluded. "Although television is frequently implicated as a cause of many problems in children, our research indicates that it may also be part of the solution." There was no difference in total viewing time between the 820 families involved in the study. The educational or "prosocial" programs included Sesame Street, Dora the Explorer and Super Why. A second category of shows also promoted co-operative problem-solving and non-violent conflict resolution but inconsistently, such as on Mickey Mouse Clubhouse. © CBC 2013

Related chapters from BN: 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 4: Development of the Brain
Link ID: 17815 - Posted: 02.18.2013

By BENEDICT CAREY The young men who opened fire at Columbine High School, at the movie theater in Aurora, Colo., and in other massacres had this in common: they were video gamers who seemed to be acting out some dark digital fantasy. It was as if all that exposure to computerized violence gave them the idea to go on a rampage — or at least fueled their urges. Social scientists have been studying and debating the effects of media violence on behavior since the 1950s, and video games in particular since the 1980s. The issue is especially relevant today, because the games are more realistic and bloodier than ever, and because most American boys play them at some point. Girls play at lower rates and are significantly less likely to play violent games. A burst of new research has begun to clarify what can and cannot be said about the effects of violent gaming. Playing the games can and does stir hostile urges and mildly aggressive behavior in the short term. Moreover, youngsters who develop a gaming habit can become slightly more aggressive — as measured by clashes with peers, for instance — at least over a period of a year or two. Yet it is not at all clear whether, over longer periods, such a habit increases the likelihood that a person will commit a violent crime, like murder, rape, or assault, much less a Newtown-like massacre. (Such calculated rampages are too rare to study in any rigorous way, researchers agree.) “I don’t know that a psychological study can ever answer that question definitively,” said Michael R. Ward, an economist at the University of Texas, Arlington. “We are left to glean what we can from the data and research on video game use that we have.” © 2013 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17795 - Posted: 02.13.2013

US President Barack Obama waded directly into scientific politics yesterday when he announced a series of measures addressing gun violence in the wake of the 14 December shooting in a primary school in Newtown, Connecticut, that left 26 people dead — 20 of them children. Of the 23 actions he took under presidential authority on 16 January, Obama chose to highlight just a few in remarks he delivered at the White House. One of them was a presidential memorandum directing the Centers for Disease Control and Prevention (CDC) and other public-health service agencies to “conduct or sponsor research into the causes of gun violence and the ways to prevent it”. An accompanying White House document added: The CDC will start immediately by assessing existing strategies for preventing gun violence and identifying the most pressing research questions, with the greatest potential public health impact. And the Administration is calling on Congress to provide $10 million for the CDC to conduct further research, including investigating the relationship between video games, media images, and violence. The presidential move is a direct challenge to gun-rights proponents in Congress, who since 1996 have used prohibitions written into funding bills to muzzle CDC research on gun violence, as Nature noted in an August 2012 editorial (see ‘Who calls the shots?’). Congress also last year began forbidding the National Institutes of Health (NIH) to spend any money, “in whole or in part, to advocate or promote gun control.” © 2013 Nature Publishing Group

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17695 - Posted: 01.19.2013

by Sara Reardon In the dark expanses of the Sonoran desert in the US, a terrifying creature stalks the night, searching for fresh meat. Anything will do: crickets, rodents, tarantulas – the nastier the better. Even the poisonous scorpion cannot escape the savage monster's little pink paws. It fights bravely, stinging its attacker on the nose. To no avail. The mouse ignores the painful venom and cruelly breaks the scorpion's tail by pummelling it into the ground, then bites its head and feasts on its flesh. Throwing its head back, the murderous animal howls at the moon. No, it's not the mythical Chupacabra. It's the southern grasshopper mouse (Onychomys torridus), the only carnivorous mouse in North America. Its unique biology and resistance to scorpion venom may one day help researchers treat human pain disorders. But for now, it's just after blood. Natural born killer From the day they are born, grasshopper mice are natural killers. Even pups born and raised in captivity quickly figure out how to take down prey much larger than themselves. They appear to learn some of their aggression from their fathers: pups raised with two parents are more likely to bully other mice and attack insects more viciously than those raised by single mothers (Behavioral Biology, DOI: 10.1016/S0091-6773(77)91933-2) © Copyright Reed Business Information Ltd.

Related chapters from BN: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 17670 - Posted: 01.12.2013

Fighting may have shaped the evolution of the human hand, according to a new study by a US team. The University of Utah researchers used instruments to measure the forces and acceleration when martial artists hit a punch bag. They found that the structure of the fist provides support that increases the ability of the knuckles to transmit "punching" force. Details have been published in the Journal of Experimental Biology. "We asked the question: 'can you strike harder with a fist than with an open palm?'," co-author David Carrier told BBC News. "We were surprised because the fist strikes were not more forceful than the strikes with the palm. In terms of the work on the bag there is really no difference." Of course, the surface that strikes the target with a fist is smaller, so there is more stress from a fist strike. "The force per area is higher in a fist strike and that is what causes localised tissue damage," said Prof Carrier. BBC © 2012

Related chapters from BN: 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: 17629 - Posted: 12.22.2012

By Kate Shaw Early one morning I caught sight of Morpheus, silhouetted against a pink African dawn. Her long, sloping neck was stretched out as she loped away from me, disappearing over a hill. I followed her to a nearby plain and was met with the unmistakable sound of a group of hyenas squabbling over a carcass. Morpheus entered the fray, first lunging at a smaller male on her right. A moment later, she looked up briefly, her nose and mouth covered in blood, then turned and snapped at a hyena feeding nearby. I’m intimately acquainted with Morpheus and these other hyenas because they have been studied for more than twenty years by various members of the lab where I did my Ph.D. research; I’ve staked these hyenas out at dens for hours on end and followed them as they raced across open plains. From watching these animals, we’ve learned about hyenas’ social system, their physiology, and the conservation challenges they face. But to me, it’s the aggression that is the most fascinating thing about hyenas. It’s rule-based and constrained by specific social norms, but at the same time, it’s incredibly primal and ruthless. Studying aggression has helped us understand what makes hyenas tick, offering us a glimpse into the evolutionary pressures that have made them one of the most unusual and misunderstood species in the animal kingdom. For more than 1000 years, people believed that hyenas were hermaphrodites, since female hyenas have long, fully-erectile pseudopenises that mimic male genitalia. Seeing a hyena play the role of mom while sporting what looks like a penis would bewilder even an astute naturalist. Not only do female hyenas look like males, they are also the more aggressive and socially dominant sex, exhibiting aggression more than three times more often than male hyenas do. © 2012 Scientific American

Related chapters from BN: 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: 17560 - Posted: 12.01.2012

By Caroline Parkinson Health editor, BBC News website The brains of teenage girls with behavioural disorders are different to those of their peers, UK researchers have found. The Journal of Child Psychology and Psychiatry study of 40 girls revealed differences in the structure of areas linked to empathy and emotions. Previous work has found similar results in boys. Experts suggest it may be possible to use scans to spot problems early, then offer social or psychological help. An estimated five in every 100 teenagers in the UK are classed as having a conduct disorder. It is a psychiatric condition which leads people to behave in aggressive and anti-social ways, and which can increase the risk of mental and physical health problems in adulthood. Rates have risen significantly among adolescent girls in recent years, while levels in males have remained about the same. In this study, funded by the Wellcome Trust and Medical Research Council, UK and Italian researchers conducted brain scans of 22 teenage girls who had conduct disorder and compared them with scans of 20 who did not. BBC © 2012

Related chapters from BN: 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: 17402 - Posted: 10.22.2012

Young people who sustain brain injuries are more likely to commit crimes and end up in prison, research suggests. The University of Exeter study says such injuries can lead maturing brains to "misfire", affecting judgement and the ability to control impulses. It calls for greater monitoring and treatment to prevent later problems. The findings echo a separate report by the Children's Commissioner for England on the impact of injuries on maturing brains and the social consequences. In the report, Repairing Shattered Lives, Professor Huw Williams from the University of Exeter's Centre for Clinical Neuropsychology Research, describes traumatic brain injury as a "silent epidemic". It is said to occur most frequently among children and young people who have fallen over or been playing sport, as well as those involved in fights or road accidents. The consequences can include loss of memory, with the report citing international research which indicates the level of brain injuries among offenders is much higher than in the general population. A survey of 200 adult male prisoners in Britain found 60% claimed to have suffered a head injury, it notes. The report acknowledges there may be underlying risk factors for brain injury and offending behaviour but says improving treatment and introducing screening for young offenders would deliver significant benefits in terms of reducing crime and saving public money. BBC © 2012

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Lateralization
Link ID: 17398 - Posted: 10.20.2012

By Jason G. Goldman When my brother and I were young, we were very careful to share the last bit of dessert equally. It’s not that we were particularly magnanimous. In their wisdom, my parents instituted a rule in our house: one of us would divide the snack in half, and the other would select his half. “You cut, I choose” was a common phrase in the Goldman household throughout the 1990s. The rule ensured that we’d each be as equitable as possible when in the role of divider. The kitchen ruler was retrieved on more than one occasion. If I thought I could have gotten away with scarfing down the last cookie without him noticing, I’m sure I would have done it. And I would not have been sorry. Imagine, however, what would have happened if my brother had decided to keep the entire last cookie for himself and run into the living room with it. Here’s one way he might have kept me from snatching my fair share of the snack: find a decent hiding spot, and if I got too close, he could run back into the kitchen. Once back in the kitchen, if I got too close to him, he could have gotten up and run back to the living room. This is called a “stimulus-response rule.” Eventually, being the bright child that I was, I would have caught onto the pattern and found a way to block his path from one room to the other, increasing the chance of getting some of the dessert. Here’s a better method that my brother could use to protect his treat: keep his eyes on me the entire time, always moving away from me so that the distance between us was, on average, fixed. If I go right, he goes left. If I move towards him, he backs up. Short of backing him into a corner, my efforts would be futile. That’s because instead of using a small set of predictable actions, my brother could call upon a wider range of behaviors. Its much harder for a thief to learn how you protect your food if your behaviors are variable than if they are predictable. This is called a “cybernetic rule.” © 2012 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17337 - Posted: 10.06.2012

By Melinda Wenner Moyer Read any Web forum, and you'll agree: people are meaner online than in “real life.” Psychologists have largely blamed this disinhibition on anonymity and invisibility: when you're online, no one knows who you are or what you look like. A new study in Computers in Human Behavior, however, suggests that above and beyond anything else, we're nasty on the Internet because we don't make eye contact with our compatriots. Researchers at the University of Haifa in Israel asked 71 pairs of college students who did not know one another to debate an issue over Instant Messenger and try to come up with an agreeable solution. The pairs, seated in different rooms, chatted in various conditions: some were asked to share personal, identifying details; others could see side views of their partner's body through webcams; and others were asked to maintain near-constant eye contact with the aid of close-up cameras attached to the top of their computer. Far more than anonymity or invisibility, whether or not the subjects had to look into their partner's eyes predicted how mean they were. When their eyes were hidden, participants were twice as likely to be hostile. Even if the subjects were both unrecognizable (with only their eyes on screen) and anonymous, they rarely made threats if they maintained eye contact. Although no one knows exactly why eye contact is so crucial, lead author and behavioral scientist Noam Lapidot-Lefler, now at the Max Stern Yezreel Valley College in Israel, notes that seeing a partner's eyes “helps you understand the other person's feelings, the signals that the person is trying to send you,” which fosters empathy and communication. © 2012 Scientific American,

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17266 - Posted: 09.17.2012

Jeannine Stamatakis psychologist John Watson, the founder of behaviorism, once said, “Give me a dozen healthy infants, well formed, and my own specified world to bring them up in, and I'll guarantee to take any one at random and train him to become any type of specialist I might select.” If we take Watson's logic one step further, it may be possible to mold someone into a psychopath. Psychopathy, also called sociopathy, is defined by a lack of empathy, deceitfulness and complete selfishness. Current thinking is that although certain genes may predispose people toward psychopathy, their environment seems to provide the ultimate catalyst. Thus, a person who possesses the particular genes associated with this malady and is brought up in an abusive or neglectful household will be at a higher risk of exhibiting the traits associated with this disorder. Severe trauma to specific regions of the brain can cause a person to undergo marked personality changes, such as in the famous case of Phineas Gage. While working as a railroad construction foreman in Vermont in 1848, he survived an accident in which a large iron rod was driven through his head, damaging much of his brain's left frontal lobe. Although he did not become a sociopath, the reported effects on his personality and behavior were so profound that friends saw him as “no longer Gage.” An incident two decades ago supports the idea that brain trauma can lead to psychopathic behaviors. In 1991 convicted sex offender Phillip Garrido kidnapped 11-year-old Jaycee Dugard and kept her as a prisoner in his home for 18 years. Experts believe that Garrido experienced severe brain damage after a serious motorcycle accident as a teenager, which was compounded by intense drug use. Garrido's father said that his son had been a “good boy” as a child but that he had changed radically after the accident and had become unstable. © 2012 Scientific American,

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 15: Language and Lateralization
Link ID: 17222 - Posted: 09.07.2012

By Bruce Bower A callous, manipulative psychopath convicted of a brutal crime can count on a long prison stint. But a judge may issue a slightly shorter sentence if presented with a biological explanation for the criminal’s psychopathic personality. Supplying judges with scientific evidence about suspected brain deficits in psychopathy led to a reduction in prison sentences from about 14 years to 13 years, researchers report in the Aug. 17 Science. The results come from a nationwide, online survey of state judges given a hypothetical scenario about a psychopath convicted of what lawyers call aggravated battery. Judges taking the survey tended to view psychopathic criminals as dangerous, whether or not scientific evidence was introduced, say psychologist Lisa Aspinwall, lawyer Teneille Brown and philosopher James Tabery, all of the University of Utah in Salt Lake City. A hypothetical psychopath in the new study got sent to the slammer for longer than the average nine-year sentence given to non-psychopaths found guilty of aggravated battery in real courts. Aspinwall and her colleagues informed judges that clinicians use psychopathy — which is not an official psychiatric diagnosis — to refer to individuals who are impulsive, emotionally shallow, outwardly charming, lacking in empathy or remorse, chronic liars and callous manipulators (SN: 12/9/06, p. 379). Judges were told that psychopathy is incurable. © Society for Science & the Public 2000 - 2012

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17178 - Posted: 08.18.2012

By Winnie Yu If you want to keep your cool, you might want to pass up those greasy wings and gooey dessert. A new study from the University of California, San Diego, suggests that people whose diets are higher in trans fats are more prone to aggression. Trans fats, or hydrogenated oils, have made the news in recent years because studies have strongly linked them to heart disease and cancer, and some locales have passed laws restricting their use. They are still common, however, in restaurant food and many grocery items. Beatrice Golomb, a physician and associate professor of medicine at U.C. San Diego, wondered if trans fats might affect behavior, after noting how they interact with a type of healthy fat. Past studies found that docosahexaenoic acid—or DHA, a long-chain omega-3 fatty acid—has a calming, antidepressant effect. Trans fats disrupt the chemical process that leads to the conversion of fatty acids into DHA, which led Golomb to suspect that trans fats might be linked to aggression. Her study, which was published in March in PLoS ONE, involved 1,018 men and women older than 20 who filled out a food questionnaire and several other surveys that measure impatience, irritability and aggression. Even after considering other influences, Golomb's team found a strong link between the intake of trans fats and aggression. “Trans-fatty acids were a more consistent predictor of aggression than some traditional risk factors such as age, male sex, education and smoking,” Golomb says. The findings were consistent across both sexes and across all ages, ethnicities and socioeconomic groups. © 2012 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 17110 - Posted: 08.01.2012

by Amy West Many deep-sea squid dispel an ink cloud to flee a predator, but one species goes a step farther: It ensures a getaway by counterattacking and then ditching the tips of its arms. These detached bits can continue to twitch and emit bioluminescent light—likely providing a vital distraction. By catching this strange maneuver on camera, scientists have established Octopoteuthis deletron as the only known squid to drop portions of its arms in self-defense, much as lizards drop their tails before escaping. O. deletron inhabits depths of 500 to 600 meters. Little is known about the biology of these gelatinous deep-dwellers, but recently they have begun to yield their secrets—including some bizarre mating behavior—thanks to powerful video cameras mounted on robotic submersibles operated by researchers at Monterey Bay Aquarium Research Institute (MBARI) in Moss Landing, California. Viewing some of this footage, Stephanie Bush, a postdoctoral fellow at the University of Rhode Island, Kingston, noticed many individuals with arms of different lengths, and suspected that these cephalopods lost their arms during an attack. To investigate, Bush collaborated with researchers at MBARI. With a bit of luck, the team found squid off the coast of California, and tried poking them with the control arm of the submersible. The creatures attacked the vehicle but never held on, perhaps because they couldn't grip its smooth metal surface, Bush says. Eventually, the researchers resorted to attaching the bottle-brush they used to wash their laboratory glassware to the submersible. When they nudged the next squid they encountered, the squid attacked the brush and immediately left behind parts of two arms. Fortunately the team caught the action with a high-resolution camera (see video). As the scientists erupted into cheers in the control room, Bush says she wondered why she hadn't tried this earlier. © 2010 American Association for the Advancement of Science

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 17105 - Posted: 07.30.2012

by Sarah C. P. Williams To escape a hungry wolf, a sheep doesn't have to outrun the wolf, just the other sheep in its flock. Many researchers think that such selfish behavior, not cooperation for the benefit of the whole crowd, shapes the movements of groups of animals. But the decades-old "selfish herd theory" has been hard to back up with data. Now, a detailed analysis of how a flock of sheep moves to avoid a sheepdog has found that the theory holds true. Each sheep heads to safety in the center of the flock, rather than running directly away from the dog. "It's really difficult to measure 2D spatial information on large animals in the wild," says biologist Theodore Stankowich of the University of Massachusetts, Amherst, who was not involved in the new work. "They've taken advantage of a unique opportunity to work with the sheep to answer these types of questions in a controlled environment." Studies on seals, crabs, and pigeons have shown that those animals seem to herd for selfish reasons, but the data have often been crude. Biologist Andrew King and colleagues at the Royal Veterinary College of the University of London attached GPS backpacks to 46 sheep and to a trained Australian Kelpie dog. When they released the dog to herd the sheep, they recorded the location of each animal every second. Then, they analyzed the data to determine what factors influenced each sheep's path. The movements of the sheep, the researchers reveal today online in Current Biology, could be best predicted by the center of the flock. Rather than run in a line away from the dog, scatter in all directions, or follow their nearest neighbors, the sheep all hurried toward the flock's center. The sheep began to converge when the dog was 70 meters away. Even as the flock as a whole moved, each sheep continuously competed to be as near the middle as possible. © 2010 American Association for the Advancement of Science.

Related chapters from BN: 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: 17079 - Posted: 07.24.2012

By Larry Greenemeier Shortly after moviegoers had settled in to watch a midnight premier of The Dark Night Rises on Friday morning, a heavily armed gunman entered the Aurora, Colo., theater through an emergency exit and opened fire. In just a few minutes the assailant shot more than 60 children and adults—killing at least a dozen—before police arrested him outside the theater. This massacre was the only latest in a string of eerily similar incidents in recent years involving the mass murder of civilians, spectators and bystanders by an individual with a firearm and a frightening lack of regard over its use. In April 2007 32 people were shot to death and 17 injured on the campus of Virginia Polytechnic Institute and State University in Blacksburg, Va., by a former student. In January 2011, former U.S. Rep. Gabrielle Giffords was shot in the head by an assailant who killed six people during an attack outside a Tucson supermarket. Just a few months ago a gunman killed seven people at Oikos University in Oakland, Calif. In each of these and other similar cases, the lone assailant who was either captured or found dead at the scene of the crime matched a particular profile—a disgruntled loner with grievances against societal institutions and who displayed an abhorrent inability or unwillingness to exercise control over violent impulses. Following the attempted assassination of Giffords, Scientific American spoke with Marco Iacoboni, a University of California, Los Angeles, professor of psychiatry and biobehavioral sciences and director of the school’s Transcranial Magnetic Stimulation Laboratory, about why some individuals act on their violent thoughts whereas others do not. Although details about the life of University of Colorado neuroscience Ph.D. student James Holmes, arrested for the Aurora shootings, are still being uncovered, several of Iacoboni’s observations about accused Giffords gunman Jared Lee Loughner seem apt to shed some light on the violence that recent took place Friday morning. © 2012 Scientific American,

Related chapters from BN: 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 Higher Cognition
Link ID: 17072 - Posted: 07.21.2012