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By Cathleen O’Grady As Samuel West combed through a paper that found a link between watching cartoon violence and aggression in children, he noticed something odd about the study participants. There were more than 3000—an unusually large number—and they were all 10 years old. “It was just too perfect,” says West, a Ph.D. student in social psychology at Virginia Commonwealth University. Yet West added the 2019 study, published in Aggressive Behavior and led by psychologist Qian Zhang of Southwest University of Chongqing, to his meta-analysis after a reviewer asked him to cast a wider net. West didn’t feel his vague misgivings could justify excluding it from the study pool. But after Aggressive Behavior published West’s meta-analysis last year, he was startled to find that the journal was investigating Zhang’s paper while his own was under review. It is just one of many papers of Zhang’s that have recently been called into question, casting a shadow on research into the controversial question of whether violent entertainment fosters violent behavior. Zhang denies any wrongdoing, but two papers have been retracted. Others live on in journals and meta-analyses—a “major problem” for a field with conflicting results and entrenched camps, says Amy Orben, a cognitive scientist at the University of Cambridge who studies media and behavior. And not just for the ivory tower, she says: The research shapes media warning labels and decisions by parents and health professionals. © 2021 American Association for the Advancement of Science.

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 13: Memory and Learning
Link ID: 27695 - Posted: 02.17.2021

By James Gorman It’s good to have friends, for humans and chimpanzees. But the nature and number of those friends change over time. In young adulthood, humans tend to have a lot of friendships. But as they age, social circles narrow, and people tend to keep a few good friends around and enjoy them more. This trend holds across many cultures, and one explanation has to do with awareness of one’s own mortality. Zarin P. Machanda, an anthropologist at Tufts University, and her own good friend, Alexandra G. Rosati, a psychologist and anthropologist at the University of Michigan, wondered whether chimpanzees, which they both study, would show a similar pattern even though they don’t seem to have anything like a human sense of their own inevitable death. The idea, in humans, Dr. Machanda said, is that as we get older we think, “I don’t have time for these negative people in my life, or I don’t want to waste my time with all of this negativity.” So we concentrate on a few good friends and invest in them. This explanation is called socioemotional selectivity theory. Dr. Rosati and Dr. Machanda, who is the director of long-term research at the Kibale Chimpanzee Project in Uganda, drew on many years of observations of chimps at Kibale. Along with several colleagues, they reported Thursday in the journal Science that male chimps, at least, display the very same inclinations as humans. The team looked only at interactions of male chimpanzees because males are quite gregarious and form a lot of friendships, whereas females are more tied to family groups. So male relationships were easier to analyze. The finding doesn’t prove or disprove anything about whether knowledge of death is what drives the human behavior. But it does show that our closest primate relative displays the same bonding habits for some other reason, perhaps something about aging that the two species have in common. At the very least, the finding raises questions about humans. © 2020 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: 27542 - Posted: 10.24.2020

By Rachel Nuwer With their bright saucer eyes, button noses and plump, fuzzy bodies, slow lorises — a group of small, nocturnal Asian primates — resemble adorable, living stuffed animals. But their innocuous looks belie a startling aggression: They pack vicious bites loaded with flesh-rotting venom. Even more surprising, new research reveals that the most frequent recipients of their toxic bites are other slow lorises. “This very rare, weird behavior is happening in one of our closest primate relatives,” said Anna Nekaris, a primate conservationist at Oxford Brookes University and lead author of the findings, published Monday in Current Biology. “If the killer bunnies on Monty Python were a real animal, they would be slow lorises — but they would be attacking each other.” Even before this new discovery, slow lorises already stood out as an evolutionary oddity. Scientists know of just five other types of venomous mammals: vampire bats, two species of shrew, platypuses and solenodons (an insectivorous mammal found in Cuba, the Dominican Republic and Haiti). Researchers are just beginning to untangle the many mysteries of slow loris venom. One key component resembles the protein found in cat dander that triggers allergies in humans. But other unidentified compounds seem to lend additional toxicity and cause extreme pain. Strangely, to produce the venom, the melon-sized primates raise their arms above their head and quickly lick venomous oil-secreting glands located on their upper arms. The venom then pools in their grooved canines, which are sharp enough to slice into bone. “The result of their bite is really, really horrendous,” Dr. Nekaris says. “It causes necrosis, so animals may lose an eye, a scalp or half their face.” © 2020 The New York Times Company

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 27539 - Posted: 10.21.2020

By Benedict Carey Scott Lilienfeld, an expert in personality disorders who repeatedly disturbed the order in his own field, questioning the science behind many of psychology’s conceits, popular therapies and prized tools, died on Sept. 30 at his home in Atlanta. He was 59. The cause was pancreatic cancer, his wife, Candice Basterfield, said. Dr. Lilienfeld’s career, most of it spent at Emory University in Atlanta, proceeded on two tracks: one that sought to deepen the understanding of so-called psychopathic behavior, the other to expose the many faces of pseudoscience in psychology. Psychopathy is characterized by superficial charm, grandiosity, pathological lying and a lack of empathy. Descriptions of the syndrome were rooted in research in the criminal justice system, where psychopaths often end up. In the early 1990s, Dr. Lilienfeld worked to deepen and clarify the definition. In a series of papers, he anchored a team of psychologists who identified three underlying personality features that psychopaths share, whether they commit illegal acts or not: fearless dominance, meanness and impulsivity. The psychopath does what he or she wants, without anxiety, regret or regard for the suffering of others. “When you have these three systems interacting, it’s a bad brew, and it creates the substrate for what can become psychopathy,” said Mark F. Lenzenweger, a professor of psychology at the State University of New York at Binghamton. “This was Scott’s great contribution: He helped change the thinking about psychopathy, in a profound way, by focusing on aspects of personality, rather than on a list of bad behaviors.” Dr. Lilienfeld’s parallel career encompassed clinical psychology and aimed to shake it free of empty theorizing, softheadedness and bad practice. In the late 1990s and early 2000s, he led a loose group of researchers who began to question the validity of some of the field’s favored constructs, like repressed memories of abuse and multiple personality disorder. The Rorschach inkblot test took a direct hit as largely unreliable. The group also attacked treatments including psychological debriefing and eye movement desensitization and reprocessing, or E.M.D.R., both of which are used for trauma victims. © 2020 The New York Times Company

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: 27529 - Posted: 10.19.2020

By Priyanka Runwal Acorn woodpeckers are renowned food hoarders. Every fall they stash as many as thousands of acorns in holes drilled into dead tree stumps in preparation for winter. Guarding these “granary trees” against acorn theft is a fierce, familial affair. But all hell breaks loose when there are deaths in a family and newly vacant spots in prime habitat are up for grabs. The news travels fast. Nearby woodpecker groups rush to the site and fight long, gory battles until one collective wins, according to a study published Monday in Current Biology. These wars also draw woodpecker audiences, the researchers reported, who leave their own territories unattended, demonstrating the immense investment and risks the birds are willing to take in pursuit of better breeding opportunities and intelligence gathering. “I think these power struggles are major events in the birds’ social calendars,” said Sahas Barve, an avian biologist at the Smithsonian National Museum of Natural History and lead author of the study. “They’re definitely trying to get social information out of it.” Acorn woodpecker societies are complex. Each family consists of up to seven adult males, often brothers, which breed with one to three females, often sisters but unrelated to the males. They live with nest helpers who are typically their offspring from previous years. Together they defend 15-acre territories, on average, encompassing one or more granaries in the oak forests along coastal Oregon down into Mexico. The helpers don’t breed, but stick around for five to six years to help raise their half-siblings until these babysitters can find a new territory to start their own families. “It’s all about biding your time and gaining indirect fitness,” Dr. Barve said. “But it’s never as good as reproducing directly.” © 2020 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: 27472 - Posted: 09.14.2020

By Carolyn Wilke Female hyenas may be out for cubs’ blood — even within their own clans. New research suggests that infanticide may be part of a strategy females use to maintain their social standing. “It’s not that these events are weird one-off things … this is actually a pretty significant source of mortality,” says Eli Strauss, a behavioral ecologist at the University of Nebraska–Lincoln. Strauss and his colleagues scoured three decades of data on spotted hyena populations in Kenya to study deaths of cubs less than a year old (SN: 4/23/02). Of 99 observed deaths, 21 could be attributed to infanticide, always by female killers. Starvation and lions also took many young cubs’ lives. The infanticide observations made the team wonder why hyenas kill within their own group. It “seems sort of counterintuitive if animals benefit from living socially,” Strauss says. Though hyenas spend much of their time alone, group living allows them to defend their turf against rival hyena clans and to gang up against threatening lions, he says. Hyena mothers give birth in an isolated den. But typically within a few weeks, they move their cubs to a communal den. Such dens shelter little ones from large predators that can’t enter the sanctuary’s small access holes, says Ally Brown, an environmental biology student at Michigan State University in East Lansing. But the communal den presents other risks — all the cases of infanticide occurred in its vicinity, documented by researchers who either found the dead cubs or observed the clans from cars that serve as mobile blinds (SN: 4/23/02). © Society for Science & the Public 2000–2020.

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 27436 - Posted: 08.26.2020

Sharks have more complex social lives than previously known, as shown by a study finding that gray reef sharks in the Pacific Ocean cultivate surprising social networks with one another and develop bonds that can endure for years. The research focused on the social behavior of 41 reef sharks around the Palmyra Atoll, about 1,000 miles southwest of Hawaii, using acoustic transmitters to track them and camera tags to gain greater clarity into their interactions. Far from being solitary creatures, the sharks formed social communities that remained rather stable over time, with some of the same individuals remaining together during the four years of the study. The researchers documented a daily pattern, with sharks spending mornings together in groups of sometimes close to 20 individuals in the same part of the reef, dispersing throughout the day and into the night, and reconvening the next morning. “Sharks are incredible animals and still quite misunderstood,” said Florida International University marine biologist Yannis Papastamatiou, lead author of the research published last week in the journal Proceedings of the Royal Society. “I like to talk about their ‘secret social lives’ not because they want it to be a secret, but because only recently have we developed the tools to start seeing and understanding their social lives,” Papastamatiou said. “Not all sharks are social and some are likely solitary.” The reef shark is medium-sized, reaching about six feet long. Its sociality bore similarities in terms of stability over time to certain birds and mammals but differed in that it did not involve nesting, mating, making vocalizations or friendly interactions.

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 27424 - Posted: 08.18.2020

By Elizabeth Pennisi When Muhammad Ali duked it out with Joe Frazier in the boxing ring, it’s unlikely anyone thought about what was happening to the genes inside their heads. But a new study in fighting fish has demonstrated that as the fish spar, genes in their brains begin to turn on and off in a coordinated way. It’s still unclear what those genes are doing or how they influence the skirmish, but similar changes may be happening in humans. The work is “a really cool example of the way that social interactions can get under the skin,” says Alison Bell, a behavioral ecologist at the University of Illinois, Urbana-Champaign, who was not involved with the study. The molecular basis of how animals, humans included, coordinate behaviors is a mystery. Whether it be mating or fighting, “animals need to be really good at this, but we don’t particularly know how they do it,” says Hans Hofmann, an evolutionary social neuroscientist at the University of Texas, Austin. When molecular biologist Norihiro Okada at Kitasato University in Japan first saw Siamese fighting fish (Betta splendens) on TV, he realized the animals could help solve this mystery. Native to Thailand, these goldfish-size swimmers have been bred to have very large, vibrantly colored fins and tails. Aquarium owners tend to keep their pets, or “bettas” as they are often called, separate. The fish are territorial and can get into fights that last more than 1 hour, with strikes, bites, and chases (as seen in the video below). They will even lock jaws in a fish version of an arm wrestle. Okada and colleagues videotaped more than a dozen hours of fights between 17 pairs of fish and then analyzed what happened—and when—in each fight. The longer the fight, the more the fish synchronize their behavior, timing their circling, striking, and biting more than anyone had ever realized, the researchers report today in PLOS Genetics. © 2020 American Association for the Advancement of Science.

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: 27310 - Posted: 06.19.2020

Nicola Davis Parents should not worry about their teenagers’ delinquent behaviour provided they were well behaved in their earlier childhood, according to researchers behind a study that suggests those who offend throughout their life showed antisocial behaviour from a young age and have a markedly different brain structure as adults. According to figures from the Ministry of Justice, 24% of males in England and Wales aged 10–52 in 2006 had a conviction, compared with 6% of females. Previous work has shown that crime rises in adolescence and young adulthood but that most perpetrators go on to become law-abiding adults, with only a minority – under 10% of the general population – continuing to offend throughout their life. Such trends underpin many modern criminal justice strategies, including in the UK where police can use their discretion as to whether to a young offender should enter the formal justice system. Now researchers say they have found that adults with a long history of offences show striking differences in brain structure compared with those who have stuck to the straight and narrow or who transgressed only as adolescents. “These findings underscore prior research that really highlights that there are different types of young offenders – they are not all the same. They should not all be treated the same,” said Prof Essi Viding, a co-author of the study from University College London. Prof Terrie Moffitt, another co-author of the research from Duke University in North Carolina, said the study helped to shed light on what may be behind persistent antisocial behaviour. © 2020 Guardian News & Media Limited

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: 27048 - Posted: 02.18.2020

By Jonathan Lambert Your dog’s ability to learn new tricks may be less a product of your extensive training than their underlying genetics. Among 101 dog breeds, scientists found that certain behavioral traits such as trainability or aggression were more likely to be shared by genetically similar breeds. While past studies have looked into the genetic underpinnings of dog behaviors for certain breeds, this research — published October 1 in the Proceedings of the Royal Society B — is the first to investigate a wide swath of breed diversity and find a strong genetic signal. “Anecdotally, everyone knows that different dogs have different behavioral traits,” says Noah Snyder-Mackler, a geneticist at the University of Washington in Seattle. “But we didn’t know how much or why.” Humans and dogs have lived together for at least 15,000 years (SN: 7/6/17). But only within the last 300 years or so have breeders produced varieties such as Chihuahuas and Great Danes. So, Snyder-Mackler and his colleagues considered how 101 dog breeds behave while searching for genetic similarities among breeds sharing certain personality traits. Data came from two dog genotype databases and from C-BARQ, a survey that asks owners to rank their pure-bred dog’s propensity for certain behaviors, like chasing or aggressiveness toward strangers. As a result, the study didn’t have genetic and behavioral data from the same canine individuals, which could help highlight rare genetic variants that may be nonetheless important to diversity in behaviors. © Society for Science & the Public 2000–2019

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: 26667 - Posted: 10.03.2019

/ By Rod McCullom In recent years, a steadily increasing volume of data has demonstrated that peer victimization — the clinical term for bullying — impacts hundreds of millions of children and adolescents, with the effects sometimes lasting years and, possibly, decades. The problem is even recognized as a global health challenge by the World Health Organization and the United Nations. And yet, researchers maintain there is still a limited understanding of how the behavior may physically shape the developing brain. Researchers believe more than 3.2 million American students experience bullying every year. That’s about 1 percent of the nation’s total population. Bullying is usually defined as repeated and intentional verbal, physical, and anti-social behavior that seeks to intimidate, harm, or marginalize someone perceived as smaller, weaker, or less powerful. Among younger children, common forms of bullying include abusive language and physical harm. This behavior may grow subtler with age as adolescent bullies routinely exclude, insult, and mock their targets. Sometimes this behavior escalates into “mobbing” among groups of bullies in school, work, or cyberspace. Researchers believe more than 3.2 million American students experience bullying every year. That’s about 1 percent of the nation’s total population. Among these students, about 10 to 15 percent experience “chronic” or persistent bullying that will last more than six continuous months. Experiencing chronic peer victimization is associated with lower academic achievement, higher unemployment rates, depression, anxiety, post-traumatic stress disorder, substance abuse, and self-harm and suicidal thoughts. Copyright 2019 Undark

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: 26596 - Posted: 09.10.2019

By Iliana Magra LONDON — On a spring afternoon last year, Neil Fraser was walking down the main shopping street in Aberdeen, a port city in northeastern Scotland, when something strange happened. The bacon-and-chicken sandwich he was halfway through eating suddenly vanished from his hand. The culprit? A hungry bird he hadn’t seen coming. “The sea gull flew in from behind me,” Mr. Fraser, a manager at the Old Schoolhouse pub in the city, said by phone on Wednesday. The bird knocked down his hand and, before he realized what was happening, it was all over: “The sandwich and the sea gull were both gone.” Aggressive gulls trying to snatch people’s food, and at times succeeding, have been a longstanding nuisance in Britain, and various solutions have been proposed over the years, including not feeding the birds, holding a stick or umbrella overhead and installing wires on roofs that they use for nesting. The Old Schoolhouse pub even reportedly offered customers water pistols to deflect the birds. Now, new research proposes a different approach: staring them down. A study published in the journal Biology Letters on Wednesday by the Royal Society, the world’s oldest continuous scientific society, suggested that making eye contact might be key to fending off herring gulls, a familiar sight in British seaside towns. The study, conducted late last year in coastal towns in Cornwall, in southwestern England, focused on that species, which are white-, gray- and black-feathered, with beaks of yellow and red. The researchers tried to test 74 birds by placing potato chips in front of an experimenter. Just 27 of the gulls bit the bait — a factor that the research team attributed to whether the experimenter was facing toward or away from the gull. © 2019 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: 26486 - Posted: 08.12.2019

By R. Douglas Fields From his sniper’s perch on the 32nd floor of the Mandalay Bay hotel in Las Vegas, a lone gunman fired 1,000 bullets from high-powered rifles into a crowd of concertgoers in 2017, murdering 58 innocent people and injuring 869 others. After he committed suicide at the crime scene, the mass murderer’s brain was shipped to Stanford University to seek a possible biological explanation for this depraved incident. What could the scientists possibly find during such an inspection? Quite a lot, in fact. No genetic test for homicidal behavior is in the offing. But this type of investigation can add insight into how violence is controlled by the brain. Using the same experimental methods that have enabled the tracing of brain circuits responsible for other complex human activities—including walking, speech and reading—neuroscientists now can pinpoint pathways that underlie aggressive behaviors. These new findings help to expose the underlying mechanisms at work in acts of extreme violence, such as the Las Vegas atrocity, but they also help to explain the more commonplace road rage and even a mother’s instantaneous response to any threat to her child. Physical, sometimes deadly violence is the hub of nature’s survival-of-the fittest struggle, and all animals have evolved specialized neural circuitry to execute—and control—aggressive behavior. In pioneering experiments on cats beginning in the late 1920s, Walter Hess discovered a locus deep within the hypothalamus, a brain area that unleashes violent aggression. It turns out that this is the same spot where other powerful compulsive urges and behaviors are activated, including sex, eating and drinking. When Hess stimulated this knot of neurons using a wire electrode inserted into the brain of a docile cat, the feline instantly launched into a hissing rage, attacking and killing another animal in its cage. The human brain has this same neural structure, labeled the hypothalamic attack area.

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: 26195 - Posted: 05.02.2019

By James Gorman If you want to know what makes hummingbirds tick, it’s best to avoid most poetry about them. Bird-beam of the summer day, — Whither on your sunny way? Whither? Probably off to have a bloodcurdling fight, that’s whither. John Vance Cheney wrote that verse, but let’s not point fingers. He has plenty of poetic company, all seduced by the color, beauty and teeny tininess of the hummingbird but failed to notice the ferocity burning in its rapidly beating heart. The Aztecs weren’t fooled. Their god of war, Huitzilopochtli, was a hummingbird. The Aztecs loved war, and they loved the beauty of the birds as well. It seems they didn’t find any contradiction in the marriage of beauty and bloodthirsty aggression. Scientists understood that aggression was a deep and pervasive part of hummingbird life. But they, too, have had their blind spots. The seemingly perfect match of nectar-bearing flowers to slender nectar-sipping beaks clearly showed that hummingbirds were shaped by co-evolution. It seemed clear that, evolutionarily, plants were in charge. Their need for reliable pollinators produced flowers with a shape that demanded a long slender bill. Hummingbird evolution obliged. But hummingbirds also heard the call of battle, which demanded a different evolutionary course. Some of those slender, delicate beaks have been reshaped into strong, sharp and dangerous weapons. In a recent paper organizing and summing up 10 years of research, Alejandro Rico-Guevara and his colleagues at the University of California, Berkeley, shared evidence gathered by high-speed video about how the deadly beaks are deployed in male-to-male conflict. Like the horns of bighorn sheep or the giant mandibles of stag beetles, hummingbird beaks are used to fight off rivals for mates. This is sexual selection, a narrow part of natural selection, in which the improvement of mating chances is the dominant force. © 2019 The New York Times Company

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: 25937 - Posted: 02.06.2019

By Elizabeth Pennisi A 9-year study has uncovered some unusual behavior by common bottlenose dolphins (Tursiops truncatus) living off the coast of Slovenia. Within one population of this species, the animals have divided into two groups that avoid contact by hunting at different times of day—a social strategy not known in marine mammals. Researchers used photographs of the dolphins’ dorsal fins to individually identify them. They made many observations of 38 of the animals, carefully recording the time, date, and location of each sighting. The marine mammals divided into two major groups of 19 and 13 animals each, with six animals loosely making up a third group, the team reports today in Marine Biology. The 19 members of the larger group tended to hang out—and likely hunt—while following fishing trawlers in the Bay of Trieste, which is located at the eastern top of Italy’s “boot.” The second group’s cadre of 13 never associated with boats when in the Bay of Trieste. Although the dolphins hunted in the same area, they rarely saw each other, the researchers discovered, because the larger group was in that area only between 7 a.m. and 1 p.m. local time, whereas the smaller group showed up between 6 p.m. and 9 p.m. Other studies have documented groups of dolphins that divide up the waters where they hunt, but this is the first time these marine mammals have been shown to timeshare the sea, the researchers note. Although they don’t know why—or how—the dolphins set these schedules, the fact that the animals are never in the same place likely diminishes unfriendly encounters and reduces direct competition for food. © 2018 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: 25798 - Posted: 12.20.2018

By Melinda Wenner Moyer Intuitively, it makes sense Splatterhouse and Postal 2 would serve as virtual training sessions for teens, encouraging them to act out in ways that mimic game-related violence. But many studies have failed to find a clear connection between violent game play and belligerent behavior, and the controversy over whether the shoot-‘em-up world transfers to real life has persisted for years. A new study published on October 1 in Proceedings of the National Academy of Sciences tries to resolve the controversy by weighing the findings of two dozen studies on the topic. The meta-analysis does tie violent video games to a small increase in physical aggression among adolescents and preteens. Yet debate is by no means over. Whereas the analysis was undertaken to help settle the science on the issue, researchers still disagree on the real-world significance of the findings. This new analysis attempted to navigate through the minefield of conflicting research. Many studies find gaming associated with increases in aggression, but others identify no such link. A small but vocal cadre of researchers have argued much of the work implicating video games has serious flaws in that, among other things, it measures the frequency of aggressive thoughts or language rather than physically aggressive behaviors like hitting or pushing, which have more real-world relevance. © 2018 Scientific American

Related chapters from BN: Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 11: Emotions, Aggression, and Stress
Link ID: 25518 - Posted: 10.02.2018

By Frankie Schembri Some of the deadliest mass shootings in U.S. history, including lone gunmen killing 26 people at the First Baptist Church in Sutherland Springs, Texas, and 17 students and staff at Marjory Stoneman Douglas High School in Parkland, Florida, have occurred in the past 2 years. These tragedies were preventable, says Garen Wintemute, an emergency medicine physician at the University of California (UC), Davis, Medical Center, and the director of UC Davis’s Violence Prevention Research Program. Wintemute has studied gun violence for more than 30 years and is one of the few researchers to approach the matter as an issue of public health. He has gone undercover at gun shows to document illegal activity and worked with California lawmakers to establish gun policies. Wintemute writes about his solutions to gun violence in an opinion piece published this week in The New England Journal of Medicine. Science chatted with him about the unique factors behind mass shootings and which policy interventions are most effective. This interview has been edited for clarity and length. Q: What does it mean to approach gun violence from a public health perspective? A: Firearm violence has been seen traditionally as a crime problem. But gun violence is one of our leading causes of death and injury, and the implications of this violence are huge in terms of the safety and health of our overall population. So, we treat it as we would any other major health problem. We ask: Where does it come from? How does it get amplified? Who is at risk for developing this problem? Can we learn enough to create a treatment or prevention strategy? © 2018 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: 25503 - Posted: 09.28.2018

By Frankie Schembri For animals unlucky enough to run into a carnivorous songbird known as the shrike, a quiet scurry through the woods can quickly morph into a dance with death. Loggerhead shrikes (Lanius ludovicianus), aka butcherbirds, impale their prey on spiky plants or barbed wire before delivering a death blow to the neck with their hooked beaks. Now, a new study shows how the birds can take down lizards and mice with body masses more than twice their own. Scientists used a high-speed video camera to film 28 shrikes attacking large vertebrate prey at a zoological research center on San Clemente Island in California. When the researchers examined the slowed-down footage, they found that in nearly all fatal attacks, the shrikes would first latch onto the necks of their prey, vigorously shaking them up and down. By using their prey’s neck as a pivot to whip them in wavelike motion, the shrikes could cause fatal damage to cervical vertebrae and spinal cords, the researchers report today in Biology Letters. When the team analyzed the shaking motions, they found that the shrikes could exert up to 6 gs of accelerative force. By comparison, humans in low-speed, rear-end car crashes can experience head accelerations of 2 to 12 gs, enough to cause whiplash. On a mouse’s smaller spine, these forces can be fatal. © 2018 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: 25417 - Posted: 09.05.2018

By Ingfei Chen Newtown, Connecticut. Las Vegas. Parkland, Florida. Annapolis, Maryland. And just two days ago, Jacksonville, Florida, where the details are still coming in. With each ghastly mass shooting in a school, workplace, or other public location, journalists scramble to piece together what happened, and speculation runs high as to whether the gunman had mental illness. But critics say the media coverage perpetuates deep-seated, stigmatizing attitudes about diagnoses such as schizophrenia or bipolar disorder. What can journalists do to cover the mental health connection in these mass murders in a responsible way? “Journalism is far too quick to try to guess at the ‘why’ behind these sorts of things, but speculation can have serious consequences.” Earlier this month, police investigators released a final report on the massacre at a Las Vegas concert last October, the deadliest shooting in modern American history. The motives of the 64-year-old gunman — a wealthy high-stakes gambler — remain unclear, they conceded, but he had burned through much of his fortune and shown potential signs of a troubled mind. While some news outlets made only brief reference to suspicions that the shooter may have had mental illness, others blared it. It’s a familiar theme. In recent years, the national conversation about gun violence has boiled down to a narrative — amplified by the media — that essentially blames mental illness as a prominent cause of these cold-blooded public mass shootings. Mental illness has become highly politicized in the gun-control debate, yet the link between psychiatric problems and violence isn’t so straightforward. And mental health advocates say the over-simplistic narrative unfairly labels millions of Americans who have a psychiatric diagnosis with the false stereotype of being dangerous. Copyright 2018 Undark

Related chapters from BN: 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: The Biology of Behavioral Disorders
Link ID: 25396 - Posted: 08.29.2018

By Andrew R. Calderon In 1978, Thomas Barefoot was convicted of killing a police officer in Texas. During the sentencing phase of his trial, the prosecution called two psychiatrists to testify about Barefoot’s “future dangerousness,” a capital-sentencing requirement that asked the jury to determine if the defendant posed a threat to society. The psychiatrists declared Barefoot a “criminal psychopath,” and warned that whether he was inside or outside a prison, there was a “one hundred percent and absolute chance” that he would commit future acts of violence that would “constitute a continuing threat to society.” Informed by these clinical predictions, the jury sentenced Barefoot to death. Although such psychiatric forecasting is less common now in capital cases, a battery of risk assessment tools has since been developed that aims to help courts determine appropriate sentencing, probation and parole. Many of these risk assessments use algorithms to weigh personal, psychological, historical and environmental factors to make predictions of future behavior. But it is an imperfect science, beset by accusations of racial bias and false positives. Now a group of neuroscientists at the University of New Mexico propose to use brain imaging technology to improve risk assessments. Kent Kiehl, a professor of psychology, neuroscience and the law at the University of New Mexico, said that by measuring brain structure and activity they might better predict the probability an individual will offend again.

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: 25339 - Posted: 08.16.2018