Links for Keyword: Aggression

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by Bethany Brookshire When a laboratory mouse and a house mouse come nose to nose for the first time, each one is encountering something it has never seen before. They are both Mus musculus. But the wild mouse is facing a larger, fatter, calmer and less aggressive version of itself that’s the result of brother-to-sister inbreeding for generations, resulting in mice that are almost completely genetically identical. Laboratory mice are incredibly valuable tools for research into diseases from Alzheimer’s to Zellweger syndrome. Scientists have a deep understanding of lab mouse DNA, and can use that knowledge to study how specific genes may control certain behaviors and underlie disease. But with all the inbreeding comes some traits that, while desirable in a lab mouse, may not reflect the behavior of an animal in the wild. So for some questions, and some behaviors, scientists might need something a bit wilder. A new study takes lab mice back to their roots and along the way uncovers a new gene function. Lea Chalfin and colleagues at the Weizmann Institute of Science in Rohovot, Israel, bred laboratory mice with wild mice for 10 generations. The result was a mouse with wild mouse genes and wild mouse behavior — with a few important lab mouse genes mixed in. The technique allows scientists to place specific mutations in a wild mouse. The results have interesting implications for studying the mouse species, and might provide some new ways to study human disease as well. Chalfin and her colleagues were especially interested in behaviors linked to female aggression. © Society for Science & the Public 2000 - 2013

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: 19980 - Posted: 08.20.2014

By NATALIE ANGIER SOUTH LUANGWA NATIONAL PARK, ZAMBIA — We saw the impala first, a young buck with a proud set of ridged and twisted horns, like helical rebar, bounding across the open plain at full, desperate gallop. But why? A moment later somebody in our vehicle gasped, and the answer became clear. Rising up behind the antelope, as though conjured on movie cue from the aubergine glow of the late afternoon, were six African wild dogs, running in single file. They moved with military grace and precision, their steps synchronized, their radio-dish ears cocked forward, their long, puppet-stick legs barely skimming the ground. Still, the impala had such a jump on them that the dogs couldn’t possibly catch up — could they? We gunned the engine and followed. The pace quickened. The dogs’ discipline held steady. They were closing the gap and oh, no, did I really want to watch the kill? To my embarrassed relief, the violence was taken off-screen, when prey and predators suddenly dashed up a hill and into obscuring bushes. By the time we reached the site, the dogs were well into their communal feast, their dark muzzles glazed with bright red blood, their white-tipped tails wagging in furious joy. “They are the most enthusiastic animals,” said Rosie Woodroffe of the Institute of Zoology in London, who has studied wild dogs for the last 20 years. “Other predators may be bigger and fiercer, but I would argue that there is nothing so enthusiastic as a wild dog,” she said. “They live the life domestic dogs wish they could live.” In 1997, while devising an action plan to help save the wild dog species, Lycaon pictus, Dr. Woodroffe felt anything but exuberant. Wild dogs were considered among the most endangered of Africa’s mammals; Dr. Woodroffe had yet to see one in the wild, and she feared she never would. © 2014 The New York Times Company

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: 19941 - Posted: 08.12.2014

From David Beckham’s infamous kick at France '98 to Luis Suárez chomping Giorgio Chiellini's shoulder in Brazil last week, the history of the World Cup is littered with moments of impulsive aggression that appear to defy all rational explanation. The story of human impulsivity stretches back deep into our evolutionary past. By nature, we are all prone to making quick, rash decisions that may lead to regret, and in some cases a four-month ban from international football. Impulsivity is actually a survival mechanism and was essential in the African savanna where our species evolved around a million and a half years ago. For our ancestors, the ability to make split-second decisions could make the difference between life and death. All of us have deep primal instincts but over the several hundred million years of evolution separating our reptilian ancestors from the first mammals, and eventually primates, the cognitive ability to exercise self-restraint has increased. While most living things make this decision purely as a trade-off between risk and reward, only humans can decide to exercise self-restraint on the basis of how they think they will be perceived by others – an ability that emerged some time in the past 100,000 years or so. “We evolved to be very social animals, living in large groups, and so we have developed inhibitory mechanisms in the more recently evolved parts of the prefrontal cortex,” explains Michael Price of the School of Social Sciences at the University of Brunel. “This is the social centre of the brain. Our big reason not to be impulsive is because of your reputation and how other people are going to judge you and perhaps ostracise you as we saw with Beckham in the aftermath of France ’98.” © 2014 Guardian News and Media Limited

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: 19784 - Posted: 07.03.2014

By Jonathan Webb Science reporter, BBC News A new theory suggests that our male ancestors evolved beefy facial features as a defence against fist fights. The bones most commonly broken in human punch-ups also gained the most strength in early "hominin" evolution. They are also the bones that show most divergence between males and females. The paper, in the journal Biological Reviews, argues that the reinforcements evolved amid fighting over females and resources, suggesting that violence drove key evolutionary changes. For many years, this extra strength was seen as an adaptation to a tough diet including nuts, seeds and grasses. But more recent findings, examining the wear pattern and carbon isotopes in australopith teeth, have cast some doubt on this "feeding hypothesis". "In fact, [the australopith] boisei, the 'nutcracker man', was probably eating fruit," said Prof David Carrier, the new theory's lead author and an evolutionary biologist at the University of Utah. Masculine armour Instead of diet, Prof Carrier and his co-author, physician Dr Michael Morgan, propose that violent competition demanded the development of these facial fortifications: what they call the "protective buttressing hypothesis". In support of their proposal, Carrier and Morgan offer data from modern humans fighting. Several studies from hospital emergency wards, including one from the Bristol Royal Infirmary, show that faces are particularly vulnerable to violent injuries. BBC © 2014

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: 19710 - Posted: 06.09.2014

Bullying casts a long shadow. Children who are bullied are more prone to depression and suicidal tendencies even when they grow up; they're also more likely to get sick and have headaches and stomach troubles, researchers have discovered. A new study may have found the underlying cause: A specific indicator of illness, called C-reactive protein (CRP), is higher than normal in bullying victims, even when they get older. In contrast, the bullies, by the same gauge, seem to be healthier. The researchers focused on CRP because it's a common, easily tested marker of inflammation, the runaway immune system activity that's a feature of many chronic illnesses including cardiovascular disease, diabetes, chronic pain, and depression, explains lead author William Copeland, a psychologist and epidemiologist at Duke University Medical Center in Durham, North Carolina. To link inflammation to bullying, the researchers asked 1420 youngsters between the ages of 9 and 16 whether, and how often, they had been bullied or had bullied others. Interviewers asked participants whether they felt more teased, bullied, or treated meanly by siblings, friends, and peers than other children—and whether they had upset or hurt other people on purpose, tried to get others in trouble, or forced people to do something by threatening or hurting them. The researchers took finger stick blood tests at each assessment. Interviews took place once a year until the participants turned 16, and again when they were 19 and 21. The children interviewed were participants in the larger Great Smoky Mountains Study, in which some 12,000 children in North Carolina were assessed to track the development of psychiatric conditions. In the short term, the effect of bullying on the victims was immediate. CRP levels increased along with the number of reported bullying instances, and more than doubled in those who said they'd been bullied three times or more in the previous year, compared with kids who had never been bullied. No change was seen in bullies, or in kids who hadn't been involved with bullying one way or the other, the researchers report online today in the Proceedings of the National Academy of Sciences. © 2014 American Association for the Advancement of Science.

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: 19610 - Posted: 05.13.2014

by Colin Barras PICTURE the scene: a weak leader is struggling to hold onto power as ambitious upstarts plot to take over. As tensions rise, the community splits and the killing begins. The war will last for years. No, this isn't the storyline of an HBO fantasy drama, but real events involving chimps in Tanzania's Gombe Stream National Park. A look at the social fragmentation that led to a four-year war in the 1970s now reveals similarities between the ways chimpanzee and human societies break down. Jane Goodall has been studying the chimpanzees of Gombe for over 50 years. During the early 1970s the group appeared to split in two, and friendliness was replaced by fighting. So extreme and sustained was the aggression that Goodall dubbed it a war. Joseph Feldblum at Duke University in Durham, North Carolina, and colleagues have re-examined Goodall's field notes from the chimp feeding station she established at Gombe to work out what led to the conflict. In the past, researchers have estimated the strength of social ties based on the amount of time two chimps spent together at the station. But the notes are so detailed that Feldblum could get a better idea of each chimp's social ties, for instance, by considering if the chimps arrived at the same time and from the same direction. His team then plugged this data into software that can describe the chimps' social network. They did this for several periods between 1968 and 1972, revealing when the nature of the network changed. © Copyright Reed Business Information Ltd.

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: 19591 - Posted: 05.10.2014

By JAMES GORMAN Males’ aggression toward each other is an old story throughout the animal kingdom. It’s not that females aren’t aggressive, but in many species, male-on-male battles are more common. Take fruit flies. “The males are more aggressive than females,” said David J. Anderson, a California Institute of Technology neuroscientist who knows their tussles well. Dr. Anderson runs a kind of fight club for fruit flies in his lab at Caltech, with the goal of understanding the deep evolutionary roots of very fundamental behaviors. Dr. Anderson, Kenta Asahina and a group of their colleagues recently identified one gene and a tiny group of neurons, sometimes as few as three, present only in the brains of male fruit flies, that can control aggression. The gene is also found in mammals, and has also been associated with aggression in some mammalian species, perhaps even in humans, although that is not clear. The discovery, reported in the journal Cell last month, does not tell the whole story of fly aggression. Some fighting is inextricably linked to food and mating, while the mechanism the scientists found is not. But it is a striking indication of how brain structure and chemistry work together, as well as a reminder that as different as humans and flies are, they are not always very far apart. The painstaking process of discovery, recounted step by step in the paper, gives a glimpse of modern brain research and the lengths to which scientists must go if they want to get down to the level of how neurons control behavior. “They did a huge amount of experiments,” said Ulrike Heberlein at the Janelia Farm research campus of the Howard Hughes Medical Institute. Dr. Heberlein also studies fly behavior and recently demonstrated another human-fly connection, showing that jilted male flies will turn to drink. © 2014 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: 19203 - Posted: 02.04.2014

|By Meredith Knight When most of us imagine someone in pain, we feel uncomfortable and want to help. Psychopaths do not: a callousness toward others' suffering is the central feature of a psychopathic personality. Now an imaging study finds that psychopathic inmates have deficits in a key empathy circuit in the brain, pointing to a potential therapeutic target. Jean Decety, a psychologist at the University of Chicago, and his colleagues used functional MRI to scan the brains of 121 male prison inmates while they looked at photos of a painful moment, such as a foot stepping on a nail or a finger being smashed in a drawer. The inmates were instructed to imagine the scenario happening to themselves or to another person, a perspective-switching technique that easily elicits empathy in most people. Inmates who scored the highest on a standard psychopathy test showed a normal response in pain perception and brain centers for emotion when imagining the pain for themselves. Yet when asked to imagine the scenario happening to others, their brains did not show typical connectivity between the amygdala, an area important for fear and emotional processing, and the ventromedial prefrontal cortex, a region vital for emotion regulation, empathy and morality. Some results even indicated that pleasure regions might have become active instead. The brain areas that are undercommunicating in psychopathy “are key for experiencing empathetic concern and caring for one another, which is what empathy is all about and what individuals who score high on psychopathy do not have,” Decety says. © 2014 Scientific American

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 19162 - Posted: 01.25.2014

Tim Phillips, GlobalPost As we begin 2014, we still haven’t engaged in a conversation about gun control that brings both sides together. Polls indicate a country more or less divided over how to prevent another school shooting. And while legislation has been proposed to reign in the gun lobby, sales of guns have soared. This debate is not a new one in the United States, and while it intensifies with each tragic mass shooting, the conversation rarely advances. Frustration sets in as each new action causes the other side to dig in their heels even further. We wonder: Is there another way to frame this issue? For the last 20 years I have led an international organization that works in war torn countries to negotiate an end to conflict. In places like Northern Ireland, El Salvador, South Africa and the Balkans, groups once driven to violence to defend their beliefs have put down their weapons, sat down at a table, overcome their differences and negotiated. Moving beyond conflict is, indeed, possible. One dynamic I have observed present in all successful negotiations — which is missing from our current debate over gun control — is a recognition of the role of sacred values. Social scientists define sacred values as a set of values or principles that individuals and communities hold dear to their idea of right and wrong, that define who they are and help guide their daily lives. We first came to see the critical role played by sacred values in the 1990s in dealing with the bloody conflict in Northern Ireland in which thousands of people were killed. No one used the term sacred values back then, but we could see clearly that one of the reasons negotiations to end sectarian conflict between Catholics and Protestants in Ireland were failing was because they were not recognizing or respecting the deep differences in values, cultures and identities that each side held. © 2014 Salon Media Group, Inc.

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 19119 - Posted: 01.11.2014

By MICHAEL LUO and MIKE McINTIRE Last April, workers at Middlesex Hospital in Connecticut called the police to report that a psychiatric patient named Mark Russo had threatened to shoot his mother if officers tried to take the 18 rifles and shotguns he kept at her house. Mr. Russo, who was off his medication for paranoid schizophrenia, also talked about the recent elementary school massacre in Newtown and told a nurse that he “could take a chair and kill you or bash your head in between the eyes,” court records show. The police seized the firearms, as well as seven high-capacity magazines, but Mr. Russo, 55, was eventually allowed to return to the trailer in Middletown where he lives alone. In an interview there recently, he denied that he had schizophrenia but said he was taking his medication now — though only “the smallest dose,” because he is forced to. His hospitalization, he explained, stemmed from a misunderstanding: Seeking a message from God on whether to dissociate himself from his family, he had stabbed a basketball and waited for it to reinflate itself. When it did, he told relatives they would not be seeing him again, prompting them to call the police. As for his guns, Mr. Russo is scheduled to get them back in the spring, as mandated by Connecticut law. “I don’t think they ever should have been taken out of my house,” he said. “I plan to get all my guns and ammo and knives back in April.” The Russo case highlights a central, unresolved issue in the debate over balancing public safety and the Second Amendment right to bear arms: just how powerless law enforcement can be when it comes to keeping firearms out of the hands of people who are mentally ill. Connecticut’s law giving the police broad leeway to seize and hold guns for up to a year is actually relatively strict. Most states simply adhere to the federal standard, banning gun possession only after someone is involuntarily committed to a psychiatric facility or designated as mentally ill or incompetent after a court proceeding or other formal legal process. Relatively few with mental health issues, even serious ones, reach this point. © 2013 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 19064 - Posted: 12.23.2013

By Greg Miller John McCluskey killed a vacationing couple in eastern New Mexico in 2010, set their camper trailer on fire with their bodies inside, and took off with their truck. In sentencing hearings held after his conviction, McCluskey’s lawyers argued that he should be spared the death penalty because abnormalities in his brain had made him impulsive and unable to control his behavior. Last week, a jury declared it had been unable to reach the unanimous decision required to sentence him to death. It’s not known if the brain scans and other scientific evidence played a role in McCluskey escaping the death penalty. And it’s not the first time such evidence has been introduced when the death penalty was on the line. In fact, neuroscience is making increasingly regular courtroom appearances. “It’s amazing the extent to which judges, attorneys, and juries are taking this in stride,” said Owen Jones, a legal scholar at Vanderbilt University who observed a few hours of testimony in McCluskey’s case. “Just a few generations ago, this was beyond the realm of science fiction,” Jones said. But now, “you watch the jurors and they reflect no outward manifestation of what an extraordinary thing it is to look inside another person’s brain.” ‘It’s amazing the extent to which judges, attorneys, and juries are taking this in stride.’ Nita Farahany, a bioethicist at Duke University has been tracking the rise of legal cases involving neuroscience evidence in the U.S. The number of judicial opinions mentioning neuroscience evidence tripled between 2005 and 2011, from roughly 100 to more than 300. “It’s more prevalent than my numbers show,” Farahany said. That’s because most cases involving neuroscience evidence do not result in a written judicial opinion, and those that don’t are exceedingly difficult to find. © 2013 Condé Nast.

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: 19045 - Posted: 12.17.2013

by Chelsea Whyte For chameleons, war paint isn't just an accessory, it is a battle flag. The brightness of the colours these lizards display and how rapidly they change are good indicators of which animal will win in a fight. Chameleons are famous for changing colour to hide from predators by blending into their surroundings, but they also use colour for social communication. One of the most diversely coloured species is the veiled chameleon (Chamaeleo calyptratus), which lives in parts of Saudi Arabia and Yemen. "At their brightest, they have vertical yellow stripes, blue-green bellies, black speckles that provide contrast and make their stripes stand out, and orange around the corner of their mouths," says Russell Ligon, a behavioural ecologist at Arizona State University in Tempe. To see if individual variations in these colours and patterns influenced the outcome of a fight, Ligon and his colleague Kevin McGraw staged a round-robin tournament in which 10 male veiled chameleons were pitted against each other. Using a high-speed camera, they were able to capture the brightness and colour changes from 28 points on each animal, taking into account how the colours would look to a chameleon's eye – which sees both visible and ultraviolet light. They found that males with the brightest side stripes were more likely to instigate a fight, whereas those with brighter heads that changed colour most rapidly were more likely to win. This suggests that different colours and patterns may signal different aspects of competitive behaviour – how motivated the chameleon is versus its strength. © Copyright Reed Business Information Ltd.

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: 19023 - Posted: 12.11.2013

By JAMES GORMAN Sometimes the scientists who study animal behavior solve puzzles and other times they uncover new ones. The war between mockingbirds and cowbirds is a case in point. Cowbirds are brood parasites, meaning they lay their eggs in the nests of other bird species, thus unloading the messy and demanding business of chick-rearing. They also peck holes in the eggs of the host birds, destroying as many as they can. Mockingbirds are a favorite target of this plan, and it seems to make perfect sense for them to viciously attack cowbirds when they catch them in the nest. But when Ros Gloag, then a doctoral student at Oxford, and her colleagues in Argentina looked closely at the war between chalk-browed mockingbirds and shiny cowbirds, they found something unexpected, as they reported in the November issue of Animal Behaviour. They stationed small video cameras near the nests of 40 pairs of chalk-browed mockingbirds. Over two breeding seasons they recorded more than 200 attacks on intruding cowbirds. They were surprised to find that these attacks, which their videos show to be quite vicious, did not stop the cowbirds from laying eggs. The cowbirds would hunker down and let the much large mockingbirds deliver hammer blows to the head, but in matter of seconds they would lay an egg and flee. How could such a failed strategy persist in evolution? © 2013 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: 19014 - Posted: 12.10.2013

Philip Ball Some animals, like some people, are more aggressive than others: it is just the way they are. But research suggests that for birds at least, it is not always easy to tell which is which. Some birds are inclined to give out exaggerated signs of their aggressiveness, others to underplay it. It is rather like the menacing biker who turns out to be a pussycat, or the geek who will break a bottle over your head. But the analogy with humans goes only so far, because many birds announce their aggression about mating and territory not by appearance but through song and gesture. For example, behavioural ecologist Michael Beecher and his colleagues at the University of Washington in Seattle have observed how the song sparrow (Melospiza melodia) indicates its intention to attack a dummy bird (see video above) or a loudspeaker playing bird songs by either vocalizing distinctive ‘soft songs’ or waving its wings (see video below), both of which are perceived as threatening1. Violent tendencies Both aggressive signalling and the ensuing violent behaviour vary from one bird to another, in a way that correlates with other personality traits such as boldness2. But these attributes also vary for a single individual at different times: birds can have particularly grouchy or placid days. Nonetheless, the degree of aggression implied by the precursory signals generally reflects the actual behaviour, in what evolutionary biologists call an honest signal. But it's not always honest. Earlier this year, Beecher's team showed1 that there is some variability in aggressive signalling that does not match behaviour: a bird might act stroppy but not follow through with an attack. © 2013 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: 19002 - Posted: 12.05.2013

One afternoon in October 2005, neuroscientist James Fallon was looking at brain scans of serial killers. As part of a research project at UC Irvine, he was sifting through thousands of PET scans to find anatomical patterns in the brain that correlated with psychopathic tendencies in the real world. “I was looking at many scans, scans of murderers mixed in with schizophrenics, depressives and other, normal brains,” he says. “Out of serendipity, I was also doing a study on Alzheimer’s and as part of that, had brain scans from me and everyone in my family right on my desk.” “I got to the bottom of the stack, and saw this scan that was obviously pathological,” he says, noting that it showed low activity in certain areas of the frontal and temporal lobes linked to empathy, morality and self-control. Knowing that it belonged to a member of his family, Fallon checked his lab’s PET machine for an error (it was working perfectly fine) and then decided he simply had to break the blinding that prevented him from knowing whose brain was pictured. When he looked up the code, he was greeted by an unsettling revelation: the psychopathic brain pictured in the scan was his own. Many of us would hide this discovery and never tell a soul, out of fear or embarrassment of being labeled a psychopath. Perhaps because boldness and disinhibition are noted psychopathic tendencies, Fallon has gone all in towards the opposite direction, telling the world about his finding in a TED Talk, an NPR interview and now a new book published last month, The Psychopath Inside. In it, Fallon seeks to reconcile how he—a happily married family man—could demonstrate the same anatomical patterns that marked the minds of serial killers. “I’ve never killed anybody, or raped anyone,” he says. “So the first thing I thought was that maybe my hypothesis was wrong, and that these brain areas are not reflective of psychopathy or murderous behavior.”

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: 18964 - Posted: 11.25.2013

By JOHN TIERNEY How aggressive is the human female? When the anthropologist Sarah B. Hrdy surveyed the research literature three decades ago, she concluded that “the competitive component in the nature of women remains anecdotal, intuitively sensed, but not confirmed by science.” Science has come a long way since then, as Dr. Hrdy notes in her introduction to a recent issue of Philosophical Transactions of the Royal Society devoted entirely to the topic of female aggression. She credits the “stunning” amount of new evidence partly to better research techniques and partly to the entry of so many women into scientific fields once dominated by men. The existence of female competition may seem obvious to anyone who has been in a high-school cafeteria or a singles bar, but analyzing it has been difficult because it tends be more subtle and indirect (and a lot less violent) than the male variety. Now that researchers have been looking more closely, they say that this “intrasexual competition” is the most important factor explaining the pressures that young women feel to meet standards of sexual conduct and physical appearance. The old doubts about female competitiveness derived partly from an evolutionary analysis of the reproductive odds in ancient polygynous societies in which some men were left single because dominant males had multiple wives. So men had to compete to have a chance of reproducing, whereas virtually all women were assured of it. But even in those societies, women were not passive trophies for victorious males. They had their own incentives to compete with one another for more desirable partners and more resources for their children. And now that most people live in monogamous societies, most women face the same odds as men. In fact, they face tougher odds in some places, like the many college campuses with more women than men. © 2013 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: 18940 - Posted: 11.19.2013

By DAVID P. BARASH WAR is in the air. Sad to say, there’s nothing new about this. Nor is there anything new about the claim that war has always been with us, and always will be. What is new, it seems, is the degree to which this claim is wrapped in the apparent acquiescence of science, especially the findings of evolutionary biology with respect to a war-prone “human nature.” This year, an article in The National Interest titled “What Our Primate Relatives Say About War” answered the question “Why war?” with “Because we are human.” In recent years, a piece in New Scientist asserted that warfare has “played an integral part in our evolution” and an article in the journal Science claimed that “death in warfare is so common in hunter-gatherer societies that it was an important evolutionary pressure on early Homo sapiens.” The emerging popular consensus about our biological predisposition to warfare is troubling. It is not just scientifically weak; it is also morally unfortunate, as it fosters an unjustifiably limited vision of human potential. Although there is considerable reason to think that at least some of our hominin ancestors engaged in warlike activities, there is also comparable evidence that others did not. While it is plausible that Homo sapiens owed much of its rapid brain evolution to natural selection’s favoring individuals that were smart enough to defeat their human rivals in violent competition, it is also plausible that we became highly intelligent because selection favored those of our ancestors who were especially adroit at communicating and cooperating. Conflict avoidance, reconciliation and cooperative problem solving could also have been altogether “biological” and positively selected for. © 2013 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: 18718 - Posted: 09.30.2013

by Megan Gannon, Live Science Deep in the cloud forests of Central America, two species of singing mice put on a high-pitched opera to mark their territory and stave off clashes, researchers discovered. Alston's singing mouse (Scotinomys teguina) and the Chiriqui singing mouse (S. xerampelinus) have overlapping lifestyles in the cloud forests of Costa Rica and Panama. But the tawny cousins seem to establish geographic boundaries so they can avoid competing with each other. "A long-standing question in biology is why some animals are found in particular places and not others," study researcher Bret Pasch, a postdoctoral fellow at the the University of Texas at Austin, said in a statement. "What factors govern the distribution of species across space?" As it turns out, a little communication between individuals affects the spread of both species as a whole. Both species of singing mice produce vocalizations that are barely audible to humans. As video footage of the mouse-y opera from the foggy forest floor shows, the creatures throw their heads back and belt out songs in the form of rapidly repeated notes, known as trills. The Alston's mouse in the clip even looks likes it's taking a bow after its solo. © 2013 Discovery Communications, LLC

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: 18712 - Posted: 09.28.2013

By John Horgan Once again, antidepressants have been linked to an episode of horrific violence. The New York Times reports that Aaron Alexis, who allegedly shot 12 people to death at a Navy facility in Washington, D.C., earlier this week, received a prescription for the antidepressant trazodone in August. When I first researched antidepressants almost 20 years ago, I encountered claims that they sometimes triggered violent episodes—for example, a 1989 incident in which a Kentucky man taking fluoxetine (brand name Prozac) shot to death eight co-workers and then himself. I dismissed the claims, reasoning that, because people prescribed psychiatric drugs are disturbed to begin with, it is not surprising that a tiny fraction hurt themselves and/or others. By 2004, however, in part because of lawsuits that forced pharmaceutical companies to disclose data on adverse effects, the FDA ordered antidepressant manufacturers to include a warning that antidepressants “increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of major depressive disorder (MDD) and other psychiatric disorders.” Alexis, who was 34, was reportedly seeking treatment for insomnia when he received his prescription for trazodone. Originally marketed as an antidepressant after its approval by the FDA in 1981, trazodone is also prescribed for anxiety and insomnia. Trazodone was a precursor of the extremely popular selective serotonin reuptake inhibitors (SSRIs); like the SSRIs, trazodone boosts levels of the neurotransmitter serotonin. © 2013 Scientific American

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 18682 - Posted: 09.21.2013

By JIM DWYER Here are law students on a Tuesday morning in 2013, hearing that researchers hope over the next decade or so to map the wiring of the human brain, seeing how individual cells link to bigger circuits. A decade is a sprint, less time than since 9/11, to use one benchmark. The scientists want to lift the hood and get a look at the human mind. The students, in a seminar at Fordham University School of Law taught by Prof. Deborah W. Denno, wonder what that will mean for the law. Over and over, they put questions to a guest speaker, Joshua R. Sanes, director of the Center for Brain Science at Harvard, about the implications for society if and when brain science can identify with confidence a propensity for violence, or for lying. He bats it right back at them. “You tell me,” Dr. Sanes said. “It’s a huge issue. I wish I had something smart to say.” Last year, President Obama announced that the federal government would create a Brain Initiative to speed up the development of tools that can track how the brain works and how it breaks. It is not hard to imagine the benefits, beginning with more carefully targeted treatments for people afflicted with psychiatric ailments. “There has not been a brand new type of drug for antidepression or autism or schizophrenia, bipolar disorder or O.C.D. in something like 25 years,” Dr. Sanes said. “This is where we have to make a long-term investment and come up with some new types of help because what we are doing isn’t working.” Work on animals has shown in broad strokes how information gets into the head and processed, but current imaging tools cannot keep up with the brain’s processing speed, or are not powerful enough to follow the molecular transactions involved in passing information and creating thought. © 2013 The New York Times Company

Related chapters from BP7e: Chapter 15: Emotions, Aggression, and Stress; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 18666 - Posted: 09.18.2013