Chapter 11. Emotions, Aggression, and Stress

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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

Keyword: Aggression
Link ID: 19203 - Posted: 02.04.2014

Alice Roberts Just how special do you think you are? How different do you think you are from other animals? Do you think of yourself as an animal or do you see yourself, and your fellow humans, as somehow set apart from the rest of the animal kingdom? Most of us – and I would unashamedly label us as the sensible majority of the population – accept that evolution is the best explanation for the pattern of life that we observe on the planet, both living and fossilised. However much creationists bang on about evolution being "just a theory", it beautifully explains all the evidence we have to hand (and there's masses of that: anatomical, genetic, palaeontological, embryological), without a single piece of evidence having turned up that threatens to bring the whole edifice tumbling down around our ears. So, I'm hoping you're a sensible sort of person and that you consider evolution to be as true as the spherical nature of the Earth, or the fact that the Earth orbits the sun and not vice versa. But just how comfortable are you with the idea of being a product of evolution? I think it's still, even among the most enlightened of us, really hard to come to terms with the idea that we are just another animal. A naked ape. The third chimpanzee, even. You have to admit, science has done a very good job at bringing us down a peg or two, at knocking us off the pedestal of our own construction. We can no longer view ourselves as a special creation, something created in the image of a deity and close to angels (whatever they are or look like). We can no longer see ourselves as the ultimate destination, as the pinnacle of evolution, either. Our species is just a tiny twig on the massive, dense tree of life. But that's so difficult to stomach! © 2014 Guardian News and Media Limited

Keyword: Emotions; Aggression
Link ID: 19198 - Posted: 02.04.2014

by Laura Sanders Despite seeming like a bystander, your baby is attuned to your social life (assuming you have one, which, with a baby, would be amazing). Every time you interact with someone, your wee babe is watching, eagerly slurping up social conventions. Scientists already know that babies expect some social graces: They expect people in a conversation to look at each other and talk to other people, not objects, and are eager to see good guys rewarded and bad guys punished, scientists have found. Now, a new study shows that babies are also attuned to other people’s relationships, even when those relationships have nothing to do with them. Babies are pretty good at figuring out who they want to interact with. The answer in most cases: Nice people. And that makes sense. The helpless wailers need someone reliable around to feed, change and entertain them. So to find out how good babies are at reading other people’s social relationships, University of Chicago psychologists showed 64 9-month-old babies a video of two women eating. Sometimes the women ate from the same bowl and agreed that the food was delicious, or agreed that it was gross. Sometimes the women disagreed. Later, the women interacted again, either warmly greeting each other and smiling, or giving each other the cold shoulder, arms crossed with a “hmph.” Researchers then timed how long the babies spent looking at this last scene, with the idea that the longer the baby spent looking, the more surprising the scene was. © Society for Science & the Public 2000 - 2014.

Keyword: Development of the Brain; Aggression
Link ID: 19195 - Posted: 02.01.2014

A food poisoning bacterium may be implicated in MS, say US researchers. Lab tests in mice by the team from Weill Cornell Medical College revealed a toxin made by a rare strain of Clostridium perfringens caused MS-like damage in the brain. And earlier work by the same team, published in PLoS ONE, identified the toxin-producing strain of C. perfringens in a young woman with MS. But experts urge caution, saying more work is needed to explore the link. No-one knows the exact cause of Multiple sclerosis (MS), but it is likely that a mixture of genetic and environmental factors play a role. It's a neurological condition which affects around 100,000 people in the UK. Most cases of human infection occur as food poisoning - diarrhoea and stomach cramps that usually resolve within a day or so. More rarely, the bacterium can cause gas gangrene. And a particular strain of C. perfringens, Type B, which the Weill team says it identified in a human for the first time, makes a toxin that can travel through blood to the brain. In their lab studies on rodents the researchers found that the toxin, called epsilon, crossed the blood-brain barrier and killed myelin-producing cells - the typical damage seen in MS. BBC © 2014

Keyword: Multiple Sclerosis; Aggression
Link ID: 19181 - Posted: 01.29.2014

Christie Nicholson reports. Advocates claim numerous health benefits for meditation, many of which are supported by studies on the practice. Still, meditation has not become part of mainstream medicine. So researchers at Johns Hopkins University analyzed 47 previously published clinical trials to narrow down the most effective use for meditation as medical therapy. The studies involved more than 3,500 patients suffering from various issues including stress, addiction, depression, anxiety, diabetes, heart disease, cancer and chronic pain. The meta-analysis is in the journal JAMA Internal Medicine. [Madhav Goyal et al, Meditation Programs for Psychological Stress and Well-being: A Systematic Review and Meta-analysis] Apparently practicing just 30 minutes of meditation per day significantly decreases the symptoms of anxiety and depression. An 8-week training program in mindfulness meditation – where participants have to focus on the current moment – led to optimal improvement in lowering anxiety, depression and pain. And the improvements continued over the six months following the training. For depression and anxiety, the effects of meditation were as strong as for those achieved by taking antidepressant medication. However, meditation failed to significantly affect any of the other conditions, such as heart disease or cancer. Nevertheless, while some might view meditation as sitting and doing nothing, doing nothing does something. © 2014 Scientific American

Keyword: Stress; Aggression
Link ID: 19175 - Posted: 01.28.2014

By SINDYA N. BHANOO In pursuit of a mate, male fruit flies often engage in combat, battling one another with their front legs. But when the flies are brothers, they are more likely to cooperate, researchers are reporting. In a new study in the journal Nature, Tommaso Pizzari, a zoologist at the University of Oxford, and colleagues write that brother flies live longer as a result. And there are clear benefits for females who live among brothers: They have a longer reproductive life span, a faster rate of egg production and a greater chance of laying eggs that mature to adulthood. The researchers exposed female flies in a laboratory to several different sets of males — three brothers; two brothers and an unrelated male; and three unrelated males. The most peaceful groups were the ones with three brothers, perhaps because supporting one’s kin is an alternative way to pass on common genes. “You can improve your reproductive success yourself or help individuals who also share your genes,” Dr. Pizzari said. Although fruit flies have been extensively studied in labs, the structure of their natural societies remain a bit of a mystery. © 2014 The New York Times Compan

Keyword: Sexual Behavior; Aggression
Link ID: 19168 - Posted: 01.25.2014

|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

Keyword: Aggression; Aggression
Link ID: 19162 - Posted: 01.25.2014

|By Ajai Raj As the climate heats up, tempers may follow suit, according to a study published in August 2013 in Nature. Analyzing 60 quantitative studies across fields as disparate as archaeology, criminology, economics, geography, history, political science and psychology, University of California researchers found that throughout history and across the world, higher temperatures, less rainfall and more drought were consistently linked to increased violence. The correlation held true for aggression between individuals, such as domestic abuse and assault, but was even more pronounced for conflict between groups [see timeline]. “We didn't expect for there to be nearly so many convergent findings among so many different researchers,” says economist Solomon Hsiang, now at U.C. Berkeley, who led the study. “We were actually really stunned by the level of consistency in the findings that were out there and by the size of the effects we were observing.” The researchers used statistical modeling to show that aggression scales with a combination of temperature, place and time—for example, if one U.S. county is three degrees Celsius warmer for three months or one African country is 0.6 degree C warmer for a year, statistics reveal an uptick in crime, violence and revolutionary fervor. The reasons behind the climate-violence link are complex and not fully understood, although anyone who has lived through a heat wave can attest to one simple fact: “When people are hot, it makes them cranky,” says Brian Lickel, a social psychologist who is on the faculty of the Psychology of Peace and Violence program at the University of Massachusetts Amherst and who was not involved in the study. “It makes people more prone to anger, it makes people more frustrated, and it makes decision making more impulsive. And that can lead to altercations that escalate to more extreme levels of aggression.” © 2014 Scientific American,

Keyword: Emotions; Aggression
Link ID: 19161 - Posted: 01.25.2014

By Eric Niiler, It may come as a surprise that Finland — one of the least polluted, wealthiest countries, where average life expectancy is among the world’s highest — has the highest rate of Type 1 diabetes. Each year, there are about 58 cases diagnosed per 100,000 children; in the United States there are 24 cases per 100,000, according to the International Diabetes Federation. Some researchers suspect there may be a connection between Finland’s cleanliness and the incidence of the disease there. They are investigating whether the lack of exposure to a specific group of bacteria found in the intestine may be causing weaker immune systems in Finnish children, making them more susceptible to Type 1 diabetes. This so-called hygiene hypothesis — that cleaner living can result in a weaker immune system — has also been linked to ailments such as asthma, allergies and other autoimmune diseases. “We are working along the idea that we have a trigger which most likely is an infectious agent,” said Mikael Knip, a professor of pediatrics at the University of Helsinki who has been studying diabetes for 30 years. “There is an association between such infections and appearance of antibodies.” Just as there are microbes that trigger the disease, Knip says there are also some bacterial or viral infections that, if they occur at an early age, can protect a young child from developing Type 1 diabetes. Type 1 diabetes, which affects approximately 37 million people worldwide, is an autoimmune disease in which the body does not produce sufficient insulin, a hormone needed to break down sugars. Typically diagnosed in children, teens and young adults, the disease can eventually damage the eyes and organs such as the kidneys, and it increases the likelihood of stroke and heart failure. © 1996-2014 The Washington Post

Keyword: Obesity; Aggression
Link ID: 19160 - Posted: 01.22.2014

A clean slate—that’s what people suffering from posttraumatic stress disorder (PTSD) crave most with their memories. Psychotherapy is more effective at muting more recent traumatic events than those from long ago, but a new study in mice shows that modifying the molecules that attach to our DNA may offer a route to quashing painful memories in both cases. One of the most effective treatments for PTSD is exposure psychotherapy. A behavioral psychologist asks a patient to recall and confront a traumatic event; each time the traumatic memory is revisited, it becomes susceptible to editing through a phenomenon known as memory reconsolidation. As the person relives, for example, a car crash, the details of the event—such as the color and make of the vehicle—gradually uncouple from the anxiety, reducing the likelihood of a panic attack the next time the patient sees, say, a red Mazda. Repeated therapy sessions can also lead to memory extinction, in which the fears tied to an event fade away as old memories are replaced with new ones. Yet this therapy works only for recent memories. If too much time passes before intervention, the haunting visions become stalwart, refusing to budge from the crevices of the mind. This persistence raises the question of how the brain tells the age of a memory in the first place. Researchers at the Massachusetts Institute of Technology, led by neurobiologist Li-Huei Tsai, have now uncovered a chemical modification of DNA that regulates gene activity and dictates whether a memory is too old for reconsolidation in mice. A drug that tweaks these “memory wrinkles” gives old memories a face-lift, allowing them to be edited by reconsolidation and resulting in fear extinction during behavior therapy. © 2014 American Association for the Advancement of Science.

Keyword: Learning & Memory; Aggression
Link ID: 19150 - Posted: 01.18.2014

By Meeri Kim, Rats, like humans, will show kindness to strangers, but only if the rats in distress are of a familiar type, a new study has found. Neurobiologists from the University of Chicago have discovered that rats display empathy-like behavior toward other rats, but the basis of that empathy is environmental, rather than genetic. The creatures aren’t born with an innate motivation to help rats of their own kind, but instead those with whom they are socially familiar. “Rats choose to help according to which rats they’ve had a positive social experience with in the past,” said study author and postdoctoral researcher Inbal Ben-Ami Bartal. As part of what Bartal calls the “Mowgli experiment” — a reference to the boy raised by wolves in Rudyard Kipling’s “The Jungle Book” — researchers plucked albino pups from their mothers on the day they were born and transferred them to a group of black-patched rats. As adults, the albinos refused to help other albinos but readily freed black-patched rats. “There’s no mirror in nature,” said study author and neurobiologist Peggy Mason. “They are not born with an idea of who they are, and therefore, who they should help.” The study was published online Tuesday in the journal eLife. © 1996-2014 The Washington Post

Keyword: Emotions; Aggression
Link ID: 19141 - Posted: 01.16.2014

By Arthur Allen, Cognitive psychologist Mary Czerwinski and her boyfriend were having a vigorous argument as they drove to Vancouver, B.C., from Seattle, where she works at Microsoft Research. She can’t remember the subject, but she does recall that suddenly, his phone went off, and he read out the text message: “Your friend Mary isn’t feeling well. You might want to give her a call.” At the time, Czerwinski was wearing on her wrist a wireless device intended to monitor her emotional ups and downs. Similar to the technology used in lie detector tests, it interprets signals such as heart rate and electrical changes in the skin. The argument may have been trivial, but Czerwinski’s internal response was not. That prompted the device to send a distress message to her cellphone, which broadcast it to a network of her friends. Including the one with whom she was arguing, right beside her. Czerwinski is working in affective computing, which emerged in 2000 from the laboratory of Rosalind Picard at the Massachusetts Institute of Technology. Picard and her colleagues dreamed of creating caring robots. As a first step, they decided to make machines that could detect and help us cope with our sometimes hidden emotions. One of Picard’s early projects involved helping autistic children. Because her devices were often better than the children themselves at communicating their feelings, she designed ways of feeding information from a wrist sensor to the cellphones of parents and other caretakers so they could know about the stress their children were under and respond accordingly. © 1996-2014 The Washington Post

Keyword: Emotions; Aggression
Link ID: 19134 - Posted: 01.15.2014

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.

Keyword: Aggression; Aggression
Link ID: 19119 - Posted: 01.11.2014

by Laura Sanders Baby V sailed through her first Christmas with the heart of a little explorer. She travelled to frigid upstate New York where she mashed snow in her cold little hands, tasted her great grandma’s twice baked potato and was licked clean by at least four dogs. And she opened lots of presents. It’s totally true what people say about little kids and gifts: The wrapping paper proved to be the biggest hit. But in the Christmas aftermath, one of Baby V’s new toys really caught her attention. She cannot resist her singing, talking book. The book has only three pages, but Baby V is smitten. Any time the book pipes up, which it seems to do randomly, she snaps to attention, staring at it, grabbing it and trying to figure it out. With a cutesy high-pitched voice, the book tells Baby V to “Turn the pa-AYE-ge!” and “This is fun!” Sometimes, the book bursts into little songs, all the while maintaining the cheeriest, squeakiest, sugarplum-drenched tone, even when it’s saying something kind of sad: “Three little kittens have lost their mittens and they began to cry!” The book maker (uh, author?) clearly knows how to tap into infants’ deep love for happy, squeaky noises, as does the creator of Elmo. Scientists are also noticing this trend, and are starting to figure out exactly why these sounds are so alluring to little ones. © Society for Science & the Public 2000 - 2014.

Keyword: Language; Aggression
Link ID: 19111 - Posted: 01.08.2014

Ed Yong A marine iguana (Amblyrhynchus cristatus) at the Galapagos Islands National Park rests calmly as tourists walk by — a behaviour that may have evolved because of a lack of predators. Expand When Charles Darwin visited the Galapagos Islands, he noted that many of its animal inhabitants were so unafraid of people that “a gun is here almost superfluous”. He swatted birds with his hat, pulled the tails of iguanas and sat on giant tortoises. These antics fuelled his famous idea that animals become tame when they live on remote, predator-free islands. Now, William Cooper Jr of Indiana University–Purdue University in Fort Wayne has tested Darwin's hypothesis on 66 species of lizards from around the world and found that island dwellers tended to be more docile than their continental relatives — the strongest evidence yet for this classic idea. The results are published this week in Proceedings of the Royal Society B1. Several studies and unpublished reports have shown that particular species are more approachable on islands where there are fewer predators, or quicker to flee on islands that contain introduced hunters such as feral cats. But despite this largely anecdotal evidence for island tameness, “no one has ever established that it’s a general phenomenon in any group”, says Cooper. “We showed that for a large prey group — lizards — there really is a significant decline in wariness on islands.” © 2014 Nature Publishing Group

Keyword: Evolution; Aggression
Link ID: 19107 - Posted: 01.08.2014

Stephen S. Hall Hochelaga was the original Iroquoian name for the village that ultimately became Montreal, but it is also the name of a rough-hewn French–Canadian neighbourhood located east of — and a world away from — the cosmopolitan city centre. The district's tidy two- and three-storey brick duplexes, adorned with Montreal's characteristic wrought-iron staircases, predominantly house families that have, because of poverty and lack of education, never quite attained thriving middle-class status. During the 1980s, public-school officials identified Hochelaga and many other impoverished neighbourhoods in the eastern part of Montreal as places where kindergarten children disproportionately displayed severe behavioural problems, such as physical aggression. The school system asked a young University of Montreal psychologist named Richard Tremblay for help. “Their parents didn't have a high-school diploma, and many of the mothers had their first child before the age of 20,” Tremblay says of the families he began to study, as he walks along Rue Ontario in Hochelaga on a sunny afternoon in September. Those were the women, he adds, “most at risk of having children who have problems”. Over the past three decades, Hochelaga and similar neighbourhoods have served as living laboratories in the study of the roots of aggression. Since 1984, Tremblay and his collaborators have followed more than 1,000 children from 53 schools in the city from childhood into adulthood. And in 1985, he initiated a ground-breaking experiment in which some families of at-risk children were given support and counselling to help curb bad behaviour. His research overturned ideas about when aggressive behaviour first emerges, and showed that early intervention can deflect children away from adult criminality. © 2013 Nature Publishing Group

Keyword: Epigenetics; Aggression
Link ID: 19082 - Posted: 12.31.2013

Helen Shen The ability to erase memory may jump from the realm of film fantasy (such as Eternal Sunshine of the Spotless Mind, shown here) to reality. In the film Eternal Sunshine of the Spotless Mind, unhappy lovers undergo an experimental brain treatment to erase all memories of each other from their minds. No such fix exists for real-life couples, but researchers report today in Nature Neuroscience that a targeted medical intervention helps to reduce specific negative memories in patients who are depressed1. "This is one time I would say that science is better than art," says Karim Nader, a neuroscientist at McGill University in Montreal, Canada, who was not involved in the research. "It's a very clever study." The technique, called electroconvulsive (ECT) or electroshock therapy, induces seizures by passing current into the brain through electrode pads placed on the scalp. Despite its sometimes negative reputation, ECT is an effective last-resort treatment for severe depression, and is used today in combination with anaesthesia and muscle relaxants. Marijn Kroes, a neuroscientist at Radboud University Nijmegen in the Netherlands, and his colleagues found that by strategically timing ECT bursts, they could target and disrupt patients' memory of a disturbing episode. A matter of time The strategy relies on a theory called memory reconsolidation, which proposes that memories are taken out of 'mental storage' each time they are accessed and 're-written' over time back onto the brain's circuits. Results from animal studies and limited evidence in humans suggest that during reconsolidation, memories are vulnerable to alteration or even erasure2–4. © 2013 Nature Publishing Group

Keyword: Learning & Memory; Aggression
Link ID: 19065 - Posted: 12.23.2013

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

Keyword: Aggression; Aggression
Link ID: 19064 - Posted: 12.23.2013

By JAN HOFFMAN Just in time to protect patients from the dangers of holiday cheer, a new scholarly review from a British medical journal describes many harmful effects wrought by laughter. Among the alarms it sounds: The force of laughing can dislocate jaws, prompt asthma attacks, cause headaches, make hernias protrude. It can provoke cardiac arrhythmia, syncope or even emphysema (this last, according to a clinical lecturer in 1892). Laughter can trigger the rare but possibly grievous Pilgaard-Dahl and Boerhaave’s syndromes (see explanation below). And ponder, briefly, the mortifying impact of sustained laughter on the urinary tract (detailed in a 1982 The Lancet paper entitled “Giggle Incontinence”). At the very least, the new review could be considered an affirmation for the perpetually dour. If 2013 was the year of the worried well, the authors imply that 2014 is poised to be the year of the humorless healthy. The analysis, “Laughter and MIRTH (Methodical Investigation of Risibility, Therapeutic and Harmful),” was drawn from about 5,000 studies. It appears in BMJ, formerly known as The British Medical Journal, which for more than 30 years has traditionally featured rigorously researched but lighthearted articles in its Christmas issue. A deputy editor, Dr. Tony Delamothe, said that the MIRTH study was indeed peer-reviewed — presumably by a doctor with a carefully managed sense or humor (or humour). This year, companion studies in the issue include “Were James Bond’s drinks shaken because of alcohol induced tremor?” , “The survival time of chocolates on hospital wards: covert observational study,” and “Operating room safety: the 10 point plan to safe flinging” (among the cautions: “Before flinging, identify your target and the area beyond it” and “Never fling an instrument straight up into the air”). Copyright 2013 The New York Times Company

Keyword: Emotions
Link ID: 19059 - Posted: 12.21.2013

// by Megan Gannon, Live Science News Editor Bonobos have a reputation among the great apes as "hippie chimps," and new research hints that high levels of a key thyroid hormone may play a role in keeping the animals' aggression in check. Found in the lowland forests of the Democratic Republic of the Congo, bonobos (Pan troglodytes) are closely related to chimpanzees (Pan troglodytes) but the two diverge in behavior. Bonobos seem to diffuse social tension with an impressive repertoire of sex acts rather than physical fights. Males in particular show low levels of aggression — they even maintain platonic friendships with females and stick by their mothers into adulthood. The life of male chimpanzees, meanwhile, revolves around climbing the social ladder (or at least hanging onto their current rung), and navigating cooperative and aggressive relationships with other males. [8 Humanlike Behaviors of Primates] Scientists recently found another big difference between the two Pan species: A key thyroid hormone decreases at a much later age in bonobos compared with chimps. For their study, scientists took urine samples from about 100 chimpanzees and 96 bonobos living in zoos. The researchers specifically looked at the apes' levels of triiodothyronine (T3), a hormone in the thyroid gland that is crucial for development in all vertebrates (animals with backbones). © 2013 Discovery Communications, LLC

Keyword: Hormones & Behavior; Aggression
Link ID: 19056 - Posted: 12.21.2013