By Virginia Morell Infanticide—the killing of offspring—is generally rare among birds. And when it happens, it’s usually because of outsiders that want the nesting site or territory. But what happens among birds, such as the greater ani (Crotophaga major, pictured), which have a more socialist approach to nesting? Two to four pairs of the Central and South American cuckoos (which are usually unrelated) build a single nest, and then work together to raise their chicks, which generally hatch at the same time. Intriguingly, the adults cannot recognize either their own eggs or chicks, so they care for all of them. To find out why—and if the simultaneous hatching protects the chicks from infanticide—a scientist analyzed data on nestling mortality gathered at 104 communal greater ani nests from 2006 to 2015. Of the 741 nestlings, 321 (43%) fledged and 420 (57%) died. Most of the deaths (78.5%) were due to predation. But another 13.8%, or 58 nestlings, died from infanticide, the scientist reports online today in Evolution. The remaining 32 (7.7%) died from starvation. At most of the nests, the chicks hatched within 1 day of each other. Those that first emerged from their eggs were the most likely to be dispatched by one of the nest founders, not an outsider. Chicks that hatched last were also unlucky; weaker than their older and larger nest-mates, they weren’t able to compete for food and starved. Those two pressures—infanticide and food competition—end up favoring the chicks in the middle and those that hatch on the same day, the researcher reports. © 2016 American Association for the Advancement of Science

Related chapters from BN: Chapter 6: Evolution of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 22435 - Posted: 07.14.2016

By Gary Stix Bullies often like being bullies—and an entire line of research links aggressive behaviors to brain areas tied to sensations of reward—sites deep below the organ’s surface with names like the ventromedial hypothalamus and the extended amygdala. One lingering puzzle is what precedes the aggressive act. What makes a person—or, in this case, a mouse—lash out? A new study, published June 29 in Nature, shows that the thought of being the aggressor simply feels good to certain animals. I had a fascinating talk this week with Scott Russo from the Icahn School of Medicine at Mount Sinai, the paper’s senior author, who described the significance of these findings. What did your study find? We discovered a brain circuit—connecting the basal forebrain and lateral habenula—that appears to control the motivation of a male mouse to be aggressive and subordinate another male mouse. The significance of these findings is that the circuit seems to be telling an animal that subordinating, or “bullying,” another animal is a rewarding behavior. To test this, we adapted a conditioned place preference protocol—often used to measure the rewarding properties of addictive drugs, whereby mice were allowed to attack an intruder mouse within one of two environmental contexts: When asked which of the two environmental contexts they preferred, aggressive mice chose the environment in which they were allowed to attack the intruder mouse over the environment in which they had no access to the intruder mouse. Interestingly, the basal forebrain and lateral habenula have been previously shown to support conditioned place preference to drugs of abuse, such as nicotine and cocaine, suggesting that similar neural processes mediate rewarding aspects of aggression and addictive substances. © 2016 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 22380 - Posted: 06.30.2016

By Perri Klass, M.D. In the 1990s, in my first month in practice as a pediatrician, I asked the mother of a 4-year-old about discipline and she told me that her son was often out of line and wild, and spanking was the only thing that worked, though she was sure I was going to tell her not to, just as her previous pediatrician had done. Around the same time, my colleague in the same clinic walked into an exam room to find a cranky toddler who was acting out, and a frustrated father who was taking off his belt and threatening punishment. In each case, and in many others, we had to decide how to talk to the parents, and whether to bring up the issue of child abuse — which is definitely an issue when a child is being struck, or threatened, with a belt. Corporal punishment, also known as “physical discipline,” has become illegal in recent decades in many countries, starting with Sweden in 1979. The United States is not one of those countries, and pediatricians regularly find ourselves talking with parents about why hitting children is a bad idea. The American Academy of Pediatrics officially recommends against physical discipline, saying that evidence shows it is ineffective and puts children at risk for abuse; pediatricians are mandated reporters, responsible for notifying the authorities if we think there is a possibility of abuse, though the boundaries are not clearly defined by law. But many parents continue to spank, even when they don’t think it does much good. In a recent report by the nonprofit organization Zero to Three of a national sample of 2,200 parents of children birth to age 5, parents were asked which discipline strategies they used a few times a week or more. Twenty-six percent said they “pop or swat” their child, 21 percent spank, and 17 percent reported hitting with an object like a belt or a wooden spoon. (Parents could respond that they used more than one strategy.) Zero to Three reported that even those who used these strategies frequently did not rate them as effective, and 30 percent agreed with the statement, “I spank even though I don’t feel O.K. about it.” © 2016 The New York Times Company

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: 22362 - Posted: 06.27.2016

Ian Sample Science editor Brain scans have highlighted “striking” differences between the brains of young men with antisocial behavioural problems and those of their better-behaved peers. The structural changes, seen as variations in the thickness of the brain’s cortex or outer layer of neural tissue, may result from abnormal development in early life, scientists at Cambridge University claim. But while the images show how the two groups of brains differ on average, the scans cannot be used to identify individuals with behavioural issues, nor pinpoint specific developmental glitches that underpin antisocial behaviour. Led by Luca Passamonti, a neurologist at Cambridge, the researchers scanned the brains of 58 young men aged 16 to 21 who had been diagnosed with conduct disorder, defined by persistent problems that ranged from aggressive and destructive behaviour, to lying and stealing, carrying weapons or staying out all night. When compared with brain scans from 25 healthy men of the same age, the scientists noticed clear differences. Those diagnosed with conduct disorder before the age of 10 had similar variations in the thickness of the brain’s cortex. “It may be that problems they experience in childhood affect and delay the way the cortex is developing,” said Passamonti. But the brains of men diagnosed with behavioural problems in adolescence differed in another way. Scans on them showed fewer similarities in cortical thickness than were seen in the healthy men. That, Passamonti speculates, may arise when normal brain maturation, such as the “pruning” of neurons and the connections between them, goes awry. © 2016 Guardian News and Media Limited

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: 22329 - Posted: 06.16.2016

By JAMES GORMAN This summer’s science horror blockbuster is a remake: Return of the Leaping Electric Eel! If you have any kind of phobia of slimy, snakelike creatures that can rise from the water and use their bodies like Tasers, this story — and the accompanying video — may not be for you. The original tale (there was, alas, no video) dates to 1800 when the great explorer Alexander von Humboldt was in South America and enlisted local fishermen to catch some of these eels for the new (at the time) study of electricity. He wrote that the men herded horses and mules into a shallow pond and let the eels attack by pressing themselves against the horses. The horses and mules tried to escape, but the fishermen kept them in the water until the eels used up their power. Two horses died, probably from falling and drowning. Or so Humboldt said. Though the story was widely retold, no other report of this kind of fishing-with-horses phenomenon surfaced for more than 200 years, according to Kenneth Catania, a scientist with a passion for studying the eel species in question, electrophorus electricus. In 2014, he reported on how the eels freeze their prey. They use rapid pulses of more than 600 volts generated by modified muscle cells and sent through the water. These volleys of shocks cause the muscles of prey to tense at once, stopping all movement. The eels’ bodies function like Tasers, Dr. Catania wrote. But they can also project high-voltage pulses in the water in isolated couplets rather than full volleys for a different effect. The pairs of shocks don’t freeze the prey, but cause their bodies to twitch. That movement reveals the prey’s location, and then the eels send out a rapid volley to immobilize then swallow it. Dr. Catania noticed another kind of behavior, however. He was using a metal-handled net — wearing rubber gloves — while working with eels in an aquarium, and the eels would fling themselves up the handle of the net, pressing themselves to the metal and generating rapid electric shocks. © 2016 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 22295 - Posted: 06.07.2016

Philip Ball James Frazer’s classic anthropological study The Golden Bough1 contains a harrowing chapter on human sacrifice in rituals of crop fertility and harvest among historical cultures around the world. Frazer describes sacrificial victims being crushed under huge toppling stones, slow-roasted over fires and dismembered alive. Frazer’s methods of analysis wouldn't all pass muster among anthropologists today (his work was first published in 1890), but it is hard not to conclude from his descriptions that what industrialized societies today would regard as the most extreme psychopathy has in the past been seen as normal — and indeed sacred — behaviour. In almost all societies, killing within a tribe or clan has been strongly taboo; exemption is granted only to those with great authority. Anthropologists have suspected that ritual human sacrifice serves to cement power structures — that is, it signifies who sits at the top of the social hierarchy. The idea makes intuitive sense, but until now there has been no clear evidence to support it. In a study published in Nature2, Joseph Watts, a specialist in cultural evolution at the University of Auckland in New Zealand, and his colleagues have analysed 93 traditional cultures in Austronesia (the region that loosely embraces the many small and island states in the Pacific and Indonesia) as they were before they were influenced by colonization and major world religions (generally in the late 19th and early 20th centuries). © 2016 Nature Publishing Group

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: 22070 - Posted: 04.05.2016

Brendan Maher It took less than a minute of playing League of Legends for a homophobic slur to pop up on my screen. Actually, I hadn't even started playing. It was my first attempt to join what many agree to be the world's leading online game, and I was slow to pick a character. The messages started to pour in. “Pick one, kidd,” one nudged. Then, “Choose FA GO TT.” It was an unusual spelling, and the spaces may have been added to ease the word past the game's default vulgarity filter, but the message was clear. Online gamers have a reputation for hostility. In a largely consequence-free environment inhabited mostly by anonymous and competitive young men, the antics can be downright nasty. Players harass one another for not performing well and can cheat, sabotage games and do any number of things to intentionally ruin the experience for others — a practice that gamers refer to as griefing. Racist, sexist and homophobic language is rampant; aggressors often threaten violence or urge a player to commit suicide; and from time to time, the vitriol spills beyond the confines of the game. In the notorious 'gamergate' controversy that erupted in late 2014, several women involved in the gaming industry were subjected to a campaign of harassment, including invasions of privacy and threats of death and rape. League of Legends has 67 million players and grossed an estimated US$1.25 billion in revenue last year. But it also has a reputation for toxic in-game behaviour, which its parent company, Riot Games in Los Angeles, California, sees as an obstacle to attracting and retaining players. © 2016 Nature Publishing Group

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory and Learning
Link ID: 22048 - Posted: 03.30.2016

Rich Stanton In 1976, the driving simulation Death Race was removed from an Illinois amusement park. There had, according to a news story at the time, been complaints that it encouraged players to run over pedestrians to score points. Through a series of subsequent newspaper reports, the US National Safety Council labelled the game “gross” and motoring groups demanded its removal from distribution. The first moral panic over video game violence had begun. This January, a group of four scholars published a paper analysing the links between playing violent video games at a young age and aggressive behaviour in later life. The titles mentioned in the report are around 15-years-old – one of several troubling ambiguities to be found in the research. Nevertheless, the quality and quantity of the data make this an uncommonly valuable study. Given that game violence remains a favoured bogeyman for politicians, press and pressure groups, it should be shocking that such a robust study of the phenomenon is rare. But it is, and it’s important to ask why. A history of violence With the arrival of Pong in 1973, video games became a commercial reality, but now, in 2016, they are still on the rocky path to mass acceptance that all new media must traverse. The truth is that the big targets of moral concern – Doom, Grand Theft Auto, Call of Duty – are undeniably about killing and they are undeniably popular among male teenagers. An industry report estimates that 80% of the audience for the Call of Duty series is male, and 21% is aged 10-14. Going by the 18 rating on the last three entries, that means at least a fifth of the game’s vast audience shouldn’t be playing. © 2016 Guardian News and Media Limited

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: 21970 - Posted: 03.09.2016

By Diana Kwon All of us have snapped at some point. A stranger cuts in line or a distracted driver nearly hits us and we lose our cool in a sudden fit of rage. As mass shootings continue to make headlines, it is becoming increasingly important to understand the brain circuits that underlie these flashes of emotion. R. Douglas Fields, a neuroscientist at the University of Maryland, College Park, and the National Institutes of Health, explores this very issue in his new book Why We Snap: Understanding the Rage Circuit in Your Brain (Dutton, 2016; 408 pages). After his own experience of sudden rage Fields began studying the topic and uncovered nine specific triggers, which he summarizes using the mnemonic “LIFEMORTS”: Life or limb (defending yourself against attackers); Insult; Family (protecting loved ones); Environment (protecting your territory); Mate; Order in society (responding to social injustice); Resources (gaining and safeguarding possessions); Tribe (defending your group); Stopped (escaping restraint or imprisonment). You mention in the introduction that you were compelled to write Why We Snap after a personal “snapping” incident in Barcelona: When a pickpocket snatched your wallet, you pinned him to the ground and grabbed it back. What was it like to try to understand that moment while writing and researching this book? Being pickpocketed was the inspiration for the book, but I also had the realization that this is an enormous problem that seems to be overlooked. © 2016 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 21963 - Posted: 03.07.2016

Greg Miller The crime was brutal. On November 4, 1989, after a night of heavy drinking, David Scott Detrich and a male coworker picked up a woman walking along the side of the road in Tucson, Arizona. After scoring some cocaine, the trio went back to her place, where, according to court documents, Detrich slit the woman’s throat and stabbed her 40 times. Later, the two men dumped her body in the desert. A jury convicted Detrich of kidnapping and first-degree murder in 1995, and a judge sentenced him to death. Detrich is still on death row today as the appeals process drags on, but in 2010, his lawyers achieved a victory of sorts. They claimed that Detrich had received “ineffective assistance of counsel” at his trial, because his original legal team had failed to present evidence of neuropsychological abnormalities and brain damage that might have swayed the court to give him a lesser sentence. A federal appeals court agreed. The ruling said, in effect, that Detrich had been denied his Constitutional right to a fair trial because his lawyers hadn’t called an expert witness to talk about his brain. That judicial opinion is just one of nearly 1,600 examined in a recent study documenting the expanding use of brain science in the criminal-justice system. The study, by Nita Farahany at Duke University, found that the number of judicial opinions that mention neuroscientific evidence more than doubled between 2005 and 2012. “There are good reasons to believe that the increase in published opinions involving neurobiology are just the tip of the iceberg,” says Owen Jones, a law professor at Vanderbilt who directs the MacArthur Foundation Research Network on Law and Neuroscience.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 21946 - Posted: 03.02.2016

by Helen Thompson Octopus emotions may run skin deep, researchers report January 28 in Current Biology. Changes in octopus skin color primarily function as camouflage, though some evidence points to other purposes. Biologists from Australia and the United States spied on shallow-water octopuses (Octopus tetricus, also known as the gloomy octopus) feeding in Jervis Bay, Australia. Sifting through 52 hours of footage, they saw that the animals adopted a darker hue, stood tall and spread their arms and web when being aggressive or intimidating. Other members of the same species either responded in kind and fought or turned a pale color before swimming away. Skin color changes appear to serve as a form of communication in these conflicts — the first evidence of such an octopus communication system at play in the wild, the researchers assert. The work also challenges the stereotype that octopuses are solitary and antisocial. In Jervis Bay, Australia, a gloomy octopus (Octopus tetricus) displays aggressive behaviors: dark skin color, elevated mantle and spread web. Another octopus approaches and reacts by changing its skin to a pale color before swimming away to avoid conflict. © Society for Science & the Public 2000 - 2016

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 21836 - Posted: 01.30.2016

By Zoe Kleinman Technology reporter, BBC News More than 200 academics have signed an open letter criticising controversial new research suggesting a link between violent video games and aggression. The findings were released by the American Psychological Association. It set up a taskforce that reviewed hundreds of studies and papers published between 2005 and 2013. The American Psychological Association concluded while there was "no single risk factor" to blame for aggression, violent video games did contribute. "The research demonstrates a consistent relation between violent video game use and increases in aggressive behaviour, aggressive cognitions and aggressive affect, and decreases in pro-social behaviour, empathy and sensitivity to aggression," said the report. "It is the accumulation of risk factors that tends to lead to aggressive or violent behaviour. The research reviewed here demonstrates that violent video game use is one such risk factor." However, a large group of academics said they felt the methodology of the research was deeply flawed as a significant part of material included in the study had not been subjected to peer review. "I fully acknowledge that exposure to repeated violence may have short-term effects - you would be a fool to deny that - but the long-term consequences of crime and actual violent behaviour, there is just no evidence linking violent video games with that," Dr Mark Coulson, associate professor of psychology at Middlesex University and one of the signatories of the letter told the BBC. "If you play three hours of Call of Duty you might feel a little bit pumped, but you are not going to go out and mug someone." © 2015 BBC

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress; Chapter 13: Memory and Learning
Link ID: 21310 - Posted: 08.19.2015

John von Radowitz , Press Association Psychologists have confirmed that playing violent video games is linked to aggressive and callous behaviour. A review of almost a decade of studies found that exposure to violent video games was a "risk factor" for increased aggression. But the same team of experts said there was insufficient evidence to conclude that the influence of games such as Call Of Duty and Grand Theft Auto led to criminal acts. The findings have prompted a call for more parental control over violent scenes in video games from the American Psychological Association (APA). The original version of Doom, released in 1993, was widely controversial for its unprecedented levels of graphic violence A report from the APA task force on violent media concludes: "The research demonstrates a consistent relation between violent video game use and increases in aggressive behaviour, aggressive cognitions and aggressive affect, and decreases in pro-social behaviour, empathy and sensitivity to aggression." The report said no single influence led a person to act aggressively or violently. Rather, it was an "accumulation of risk factors" that resulted in such behaviour. It added: "The research reviewed here demonstrates that violent video game use is one such risk factor." The APA has urged game creators to increase levels of parental control over the amount of violence video games contain.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 21301 - Posted: 08.17.2015

By Claire Asher City folk have a reputation for being less friendly than their rural counterparts, and the same appears to be true for garden birds. Urban song sparrows (Melospiza melodia, pictured) are more aggressive toward their neighbors than are sparrows out in the country, researchers report this month in Behavioral Ecology. But whereras the temperament of human city-dwellers is often attributed to the sheer density of people, this isn’t the case for sparrows. The team measured birds’ responses to recordings of another male’s song, noting how often males approached or attacked the speakers, and found that aggression depended not on the density of sparrows, but on the availability of food in the environment. Counterintuitively, male sparrows responded more aggressively in the city, where there tends to be more food, and rural birds became more aggressive when provided with food supplements. The authors explain that the sparrows defend food-rich, high-quality territories more aggressively, but it isn’t clear whether this is an offensive or a defensive strategy; city birds may be more aggressive because a territory with more food is more valuable to them, or because their abundant resources attract more thieves. © 2015 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: 21221 - Posted: 07.28.2015

By Greg Toppo On the morning of August 12, 2013, nearly eight months after 20-year-old Adam Lanza shot his way into Sandy Hook Elementary School in Newtown, Conn., and killed 26 people, Michael Mudry, an investigator with the Connecticut State Police, drove to nearby Danbury to try to solve a little mystery. Police had found a Garmin GPS unit in Lanza's house, and its records showed that the gunman had driven to the same spot nine times in April, May and June 2012, arriving around midnight each time and staying for hours. The GPS readout took Mudry to the vast parking lot of a suburban shopping center, about 14 miles west of Lanza's home. Workers at a movie theater there immediately recognized Lanza from a photograph. He was at the theater constantly, they told Mudry, but never to see movies. He came to the lobby to play an arcade game, the same one, over and over again, sometimes for eight to 10 hours a night. Witnesses said he would whip himself into a frenzy, and on occasion the theater manager had to unplug the game to get him to leave. Police had been scouring Lanza's home since the shootings, and on his computer hard drive they found information on weapons magazine capacities, images of Columbine killers Eric Harris and Dylan Klebold, copies of the violent movies Bloody Wednesday and Rampage, and a list of ingredients for TNT. And like many teenaged boys, Lanza owned the typical first-person shooter, fighting and action games: Call of Duty, Dead or Alive, Grand Theft Auto. © 2015 Scientific American,

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 21068 - Posted: 06.18.2015

Tina Hesman Saey COLD SPRING HARBOR, N.Y. — Taming animals makes an impression on their DNA. Domesticated animals tend to have genetic variants that affect similar biological processes, such as brain and facial development and fur coloration. Alex Cagan of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, reported the results May 6 at the Biology of Genomes conference. Cagan and colleagues examined DNA in Norway rats (Rattus norvegicus) that had been bred for 70 generations to be either tame or aggressive toward humans. Docility was associated with genetic changes in 1,880 genes in the rats. American minks (Neovison vison) bred for tameness over 15 generations had tameness-associated variants in 525 genes, including 82 that were also changed in the rats. The researchers also compared other domesticated animals, including dogs, cats, pigs and rabbits, with their wild counterparts. The domestic species and the minks had tameness-associated changes in genes for epidermal growth factor and associated proteins that stimulate growth of cells. Those proteins are important for the movement of neural crest cells within an embryo. That finding seems to support a recent hypothesis that changes in neural crest cells could be responsible for domestication syndrome, physical traits, including floppy ears, spotted coats and juvenile faces, which accompany tameness in many domestic animals. © Society for Science & the Public 2000 - 2015.

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: 20911 - Posted: 05.12.2015

By Emily Underwood A splashy headline appeared on the websites of many U.K. newspapers this morning, claiming that men whose brothers or fathers have been convicted of a sex offense are “five times more likely to commit sex crimes than the average male” and that this increased risk of committing rape or molesting a child “may run in a family’s male genes.” The study, published online today in the International Journal of Epidemiology, analyzed data from 21,566 male sex offenders convicted in Sweden between 1973 and 2009 and concluded that genetics may account for at least 40% of the likelihood of committing a sex crime. (Women, who commit less than 1% of Sweden’s sexual offenses, were omitted from the analysis.) The scientists have suggested that the new research could be used to help identify potential offenders and target high-risk families for early intervention efforts. But independent experts—and even the researchers who led the work, to a certain degree—warn that the study has some serious limitations. Here are a few reasons to take its conclusions, and the headlines, with a generous dash of salt. Alternate explanations: Most studies point to early life experiences, such as childhood abuse, as the most important risk factor for becoming a perpetrator of abuse in adulthood. The new study, however, did not include any detail about the convicted sex criminals’ early life exposure to abuse. Instead, by comparing fathers with sons, and full brothers and half-brothers reared together or apart, the scientists attempted to tease out the relative contributions of shared environment and shared genes to the risk of sexual offending. Based on their analyses, the researchers concluded that shared environment accounted for just 2% of the risk of sexual offense, while genetics accounted for roughly 40%. Although there is likely some genetic contribution to sexual offending—perhaps related to impulsivity or sex drive—the group “may be overestimating the role of genes” because their assumptions were inaccurate, says Fred Berlin, a psychiatrist and sexologist at Johns Hopkins University in Baltimore, Maryland. © 2015 American Association for the Advancement of Science.

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: 20779 - Posted: 04.10.2015

By ERICA GOODE He was described, in the immediate aftermath of the Germanwings crash, as a cheerful and careful pilot, a young man who had dreamed of flying since boyhood. But in the days since, it has seemed increasingly clear that Andreas Lubitz, 27, the plane’s co-pilot, was something far more sinister: the perpetrator of one of the worst mass murder-suicides in history. If what researchers have learned about such crimes is any indication, this notoriety may have been just what Mr. Lubitz wanted. The actions now attributed to Mr. Lubitz — taking 149 unsuspecting people with him to a horrifying death — seem in some ways unfathomable, and his full motives may never be fully understood. But studies over the last decades have begun to piece together characteristics that many who carry out such violence seem to share, among them a towering narcissism, a strong sense of grievance and a desire for infamy. Adam Lankford, an associate professor of criminal justice at the University of Alabama, said that in his research on mass killers who also took their own lives, he has found “a significant number of cases where they mention a desire for fame, glory or attention as a motive.” Before Adam Lanza, 20, the Sandy Hook Elementary School shooter, killed 20 children, six adults and himself in 2012, he wrote in an online forum, “Just look at how many fans you can find for all different types of mass murderers.” Robert Hawkins, 19, who committed suicide after killing eight people at a shopping mall in Omaha in 2007, left a note saying “I’m gonna be famous,” punctuating the sentence with an expletive. And Dylan Klebold, 17, of Columbine High School fame, bragged that the goal was to cause “the most deaths in U.S. history…we’re hoping. We’re hoping.” “Directors will be fighting over this story,” Mr. Klebold said in a video made before the massacre. © 2015 The New York Times Company

Related chapters from BN: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 12: Psychopathology: The Biology of Behavioral Disorders; Chapter 11: Emotions, Aggression, and Stress
Link ID: 20766 - Posted: 04.07.2015

When it comes to fight or flight for brawling crickets, a chemical in the brain is in charge. Being roughed up in a skirmish can trigger nerve cells in Mediterranean field crickets (Gryllus bimaculatus) to release nitric oxide, making the losing cricket run away, scientists report online March 13 in Science Advances. Watch in this video as two crickets face off. When the loser hits its limit, it flees the fight. In a second bout, the loser then tries to avoid the winner. Nitric oxide prompts this continued submissive behavior, which lasts several hours before a cricket’s will to fight returns. “If you block nitric oxide they recover quickly, and if you give them nitric oxide they don’t,” says Paul Stevenson, a coauthor of the new research and behavioral neurobiologist at Leipzig University in Germany. “It’s a very simple algorithm for controlling a very complicated social situation.” P. Stevenson and J. Rillich. Adding up the odds—Nitric oxide signaling underlies the decision to flee and post-conflict depression of aggression. Science Advances. Published online March 13, 2015.doi: 10.1126/sciadv.1500060. © Society for Science & the Public 2000 - 2015.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 20686 - Posted: 03.14.2015

By TIMOTHY WILLIAMS In January 1972, Cecil Clayton was cutting wood at his family’s sawmill in southeastern Missouri when a piece of lumber flew off the circular saw blade and struck him in the forehead. The impact caved in part of Mr. Clayton’s skull, driving bone fragments into his brain. Doctors saved his life, but in doing so had to remove 20 percent of his frontal lobe, which psychiatrists say led Mr. Clayton to be tormented for years by violent impulses, schizophrenia and extreme paranoia. In 1996, his lawyers say, those impulses drove Mr. Clayton to kill a law enforcement officer. Today, as Mr. Clayton, 74, sits on death row, his lawyers have returned to that 1972 sawmill accident in a last-ditch effort to save his life, arguing that Missouri’s death penalty law prohibits the execution of severely brain-damaged people. Lawyers for Mr. Clayton, who has an I.Q. of 71, say he should be spared because his injury has made it impossible for him to grasp the significance of his death sentence, scheduled for March 17. “There was a profound change in him that he doesn’t understand, and neither did his family,” said Elizabeth Unger Carlyle, one of Mr. Clayton’s lawyers. While several rulings by the United States Supreme Court in recent years have narrowed the criteria for executing people who have a mental illness, states continue to hold wide sway in establishing who is mentally ill. The debate surrounding Mr. Clayton involves just how profoundly his impairment has affected his ability to understand what is happening to him. Mr. Clayton is missing about 7.7 percent of his brain. © 2015 The New York Times Company

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: 20669 - Posted: 03.09.2015