Chapter 11. Emotions, Aggression, and Stress
Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.
by Jessica Hamzelou WHAT doesn't kill you makes you stronger, at least when it comes to stress and immune cells. Mice that received a cocktail of immune cells from bullied mice appeared to experience a mood boost. The unexpected discovery may have implications for treating depression. We know that prolonged bouts of stress take their toll on the immune system. That leaves us susceptible to illness, which in some cases can lead to depression. Most research on the link between immune health and mood has focused on the innate branch of the immune system – the cells that mount the first response to pathogens, says Miles Herkenham at the National Institutes of Health in Bethesda, Maryland. His team wondered if there might also be a role for the adaptive branch of the immune system, which "learns" about a pathogen in order to respond rapidly the next time it appears. To find out, the team introduced an aggressive competitor mouse into the cages of male mice. "These mice are like bullies," says Herkenham. Two weeks later, the bullied mice seemed depressed: they cowered in dark corners and seemed uninterested in the scent of a female. The team extracted their adaptive immune cells and injected them into another set of mice bred to lack these cells. This meant that the recipient mice essentially acquired the adaptive immune system of the bullied ones. © Copyright Reed Business Information Ltd.
Criminal psychopaths learn to respond differently to punishment cues than others in jail and may need more reward-focused treatments, new research suggests. Criminals such as Paul Bernardo, Ted Bundy and Clifford Olson, who scored high on psychopathy checklists, were known to be callous and unemotional. Psychopaths derive pleasure from being manipulative and use premeditated aggression to get what they want with no regard for those who are hurt. The search for what makes them tick has shown some physical differences in their brains such as reductions in grey matter. Now researchers in London, Montreal and Bethseda, Md., have used functional MRI imaging to assess how the brains of 12 violent criminals with psychopathy, 20 violent criminals with antisocial personality disorder but not psychopathy (such as those with a history of impulsivity and risk-taking), and 18 healthy people who were not criminals responded differently to rewards and punishment. "In the room with them, there's the sense that the weight of what they've done and the deleterious effect this is having on their lives doesn't really hold for them," said Dr. Nigel Blackwood of King's College London, a senior author of the paper in Wednesday's issue of Lancet Psychiatry. It's only at the moment in the scanner when the sanction of lost points cues them to change their behaviour that the differences between violent psychopaths and those with antisocial personality disorder appear. ©2015 CBC/Radio-Canada
Sara Reardon The US National Institutes of Health (NIH) has modified the way a controversial lab studies stress in monkeys in response to criticism by animal-rights activists and members of Congress who say that the research is inhumane. At issue are experiments led by Stephen Suomi, a psychologist at the US National Institute of Child Health and Human Development (NICHD) in Poolesville, Maryland. Suomi’s lab studies how removing newborn rhesus macaques from their mothers affects biological processes such as brain activity and gene expression, and behaviours such as alcohol consumption in the infants. He has performed similar experiments for about three decades, and has received roughly US$30 million over the past seven years for the work, according to the activist group People for the Ethical Treatment of Animals (PETA), which obtained documents and videos from the lab through a freedom-of-information request. In September, PETA began posting ads in the subway station near NIH’s Bethesda, Maryland, campus, and in newspapers condemning the experiments as “cruel and archaic”, and arguing that they yielded results that were not relevant to human health. The group also posted video of NIH monkey experiments on its website. PETA’s campaign drew the attention of Congress. In December, four Democratic members of the House of Representatives wrote to the NIH, demanding that the agency’s Bioethics Commission investigate the Suomi lab’s practices and the justification for the experiments. “We know what the impact is when children are taken from their parents,” says one of the lawmakers, Lucille Roybal-Allard (Democrat, California). “While [animal] research is necessary in many cases, we can’t just do it without evaluation and having a clear purpose.” © 2015 Nature Publishing Group
By Nicholas Weiler If you find people watching oddly compelling, you’re not alone. A new study suggests that gregarious European starlings (Sturnus vulgaris) get a kick out of looking at their fellow birds, even if it’s just on a computer screen. Researchers took 10 captive starlings from their flock and isolated them for 4 days in a cage with plenty of food and water and a large flat-screen monitor. Most of the birds quickly discovered that poking their beaks into one sensor in the cage flashed a life-size photograph of an unknown starling onto the screen, while a second sensor produced a picture of a suburban landscape. The lonely birds seemed to enjoy looking at other starlings, the researchers found. On average, they triggered a new starling photo every 6 minutes, 7 hours a day, for 4 days. They only threw in a landscape every 20 minutes or so. It wasn’t just that the landscapes were boring. Given the choice between photos of starlings and photos of monkeys, a second group of five birds also pecked to view their own kind three times more often. The results suggest starlings have a natural yearning for social stimulation, the authors report online this month in Animal Cognition. In the future, starlings’ drive to view photos of one another could be used to study the social rewards that knit communities together. © 2015 American Association for the Advancement of Science
|By Daniel Yudkin Imagine you are with some friends at a concert, and the bouncer approaches the group and says that, because you are all looking so ravishing tonight, he’s been instructed to offer one of you—just one!—a backstage pass to meet the artist. Do you raise your hand? For most people, this would be a no-brainer: who wouldn’t leap at the chance to meet a famous singer or secure a long-sought autograph? The results of a recent study, published in Psychological Science by Gus Cooney, Daniel Gilbert, and Timothy Wilson, however, suggest taking a second’s pause before snapping up that backstage pass. Cooney, Gilbert, and Wilson suspected that extraordinary experiences—like meeting a musical idol—carry hidden costs. They hypothesized that, while such occurrences undoubtedly make us happier in the moment, they also risk separating us from our peers, leading to a sense of isolation so unpleasant as to outweigh whatever enjoyment they initially confer. To test this idea, the researchers recruited subjects in groups of four and had them watch a video clip. Of the group, three were told that they would watch a clip that previous viewers had given a 2-star rating; the remaining subject, by contrast, was granted the opportunity to view a special 4-star clip. After watching the videos, all four subjects were given some time to talk amongst themselves, and then each reported on their general happiness. © 2015 Scientific American
Link ID: 20527 - Posted: 01.28.2015
/ by Tanya Lewis, LiveScience You know the feeling: the dryness in the mouth, the stickiness in the throat and the creeping salivation — thirst. But what causes feelings of thirst in the brain? In a new study, scientists used laser light to activate groups of neurons in the brains of mice. By targeting specific neuron groups, the scientists could make the animals drink even if they weren't thirsty, and stop drinking even if they were thirsty. Understanding how the brain causes feelings of thirst could help scientists learn what goes awry in disorders that make people drink too much or too little fluid, researchers say. "Thirst has attracted a lot of interest because it is such a basic function for all organisms," said Yuki Oka, a neuroscientist currently at the California Institute of Technology and co-author of the study published today (Jan. 26) in the journal Nature. Before this study, scientists knew which brain regions were activated by dehydration and hydration. "But key information was missing as to which were controlling thirst," Oka told Live Science. In the new study, Oka and a team of colleagues at Columbia University used a technique called optogenetics to pinpoint the origin of thirst impulses in the brains of mice. The researchers injected the mouse brains with a virus that made certain cells sensitive to laser light, and when scientists shone the laser on those cells, it caused them to turn nerve impulses "on" or "off." © 2015 Discovery Communications, LLC.
Link ID: 20525 - Posted: 01.28.2015
David Cox Bernd Heinrich was on a hike through the woods of New England when he observed something which would go on to change our perception of animal psychology. A group of ravens had gathered to feed on a dead moose. But rather than choosing to keep the bounty for themselves, they were making a strange call, one which seemed to be deliberately attracting more ravens to the feast. A biologist at the University of Vermont, Heinrich was initially confused. By helping their competitors, the ravens appeared to be defying all natural biological instinct. But as it transpired, their motivation was actually deeply selfish. The birds were juveniles who had discovered the moose in an adult raven’s territory. By inviting other ravens to join them, their intrusion was more likely to go unchallenged. Last month, an astonishing video emerged of a rhesus macaque successfully resuscitating another of its species which had been electrocuted at a train station in India. It is tempting to describe the sustained display of persistence and apparent concern as almost human. But there is a danger in viewing animal behaviour through the misty lens of human emotion. What both Heinrich’s “sharing ravens’ and the macaques of Kampur do provide is a window into the gradual evolution of one of the most human of traits – altruism. Altruism in its purest form should be an entirely selfless action. “If there’s any kind of selfish interest at stake, like secretly hoping for a return favour or even doing it deliberately because you know it will make you feel good, then that doesn’t really count at all,” says psychologist Michael Platt of the Center for Cognitive Neuroscience at Duke University, North Carolina.
By ERICA GOODE A goat frolics with a baby rhinoceros. A pig nestles up to a house cat. A rat snake makes nice with the dwarf hamster originally intended as its lunch. Few things seem to capture the public imagination more reliably than friendly interactions between different species — a fact not lost on Anheuser-Busch, which during Sunday’s Super Bowl will offer a sequel to “Puppy Love,” its wildly popular 2014 Budweiser commercial about friendship between a Clydesdale and a yellow Labrador puppy. The earlier Super Bowl spot has drawn more than 55 million views on YouTube. Videos of unlikely animal pairs romping or snuggling have become so common that they are piquing the interest of some scientists, who say they invite more systematic study. Among other things, researchers say, the alliances could add to an understanding of how species communicate, what propels certain animals to connect across species lines and the degree to which some animals can adopt the behaviors of other species. “There’s no question that studying these relationships can give you some insight into the factors that go into normal relationships,” said Gordon Burghardt, a professor in the departments of psychology and ecology and evolutionary biology at the University of Tennessee, who added that one video he liked to show students was of a small and persistent tortoise tussling over a ball with a Jack Russell terrier. “Even one example raises the possibility that there’s something interesting going on here,” Dr. Burghardt said. Science has not entirely ignored unusual interactions between species. Biologists have described relationships formed to achieve a specific goal, like the cooperative hunting between groupers and moray eels. And in the mid-1900s, Konrad Lorenz and other ethologists demonstrated that during critical periods after birth, certain birds and other animals would follow the first moving object they saw, whether animal, human or machine, a phenomenon known as imprinting. Dr. Lorenz was famously photographed with a gaggle of “imprinted” geese trailing behind him. © 2015 The New York Times Company
By Bruce Bower Alexithymia: An inability to find words to describe one’s own feelings Mental health workers regard alexithymia as more akin to a personality trait than to a mental disorder. Many people with psychiatric conditions such as autism spectrum disorder and panic disorder — characterized by physical symptoms with emotional causes — also display alexithymia. Researchers are finding that alexithymia has the same effect on people with and without mental disorders and that it undermines the ability to describe others’ feelings as well as one’s own. A study appearing online January 21 in Royal Society Open Science found that nine of 21 young women with eating disorders had difficulty recognizing others’ facial emotions and that this characteristic was probably related to alexithymia, not some inherent feature of anorexia or bulimia. The researchers also looked at 21 women who had alexithymia but no psychiatric disorders and found that seven had comparable problems identifying others’ expressions of happiness, fear and other emotions. Citations R. Brewer et al. Emotion recognition deficits in eating disorders are explained by co-occurring alexithymia. Royal Society Open Science. Published online January 21, 2015. doi: 10.1098/rsos.140382. © Society for Science & the Public 2000 - 2015.
By Susan Chenelle and Audrey Fisch “Lord of the Flies” has been a classroom staple for decades, perhaps because the issues of bullying and male aggression remain central concerns in the lives of adolescents, even if they aren’t stranded on a desert island. “To Study Aggression, a Fight Club for Flies” zeros in on the issue of male aggression, but in fruit flies, rather than humans. The connections, beyond the titular, are tantalizing. James Gorman, the science reporter, is focused on research about the neuropeptide tachykinin, produced in the brains of male fruit flies only. When researchers manipulated the neurons, they could decrease aggression in the flies. What does this suggest about the neuroscience of aggression? And what is the relationship between aggression and gender? Below, we match Mr. Gorman’s article with a passage from Chapter 8 of “Lord of the Flies” in which Jack leads his peers in the hunt of a sow. At this point in the novel, Jack has overthrown Ralph and Piggy’s attempts to establish order and civility among the boys. Jack has won over a majority of the boys, and in this scene the group engages in a collective hunt for food that transforms itself into a kind of orgy of male violence. The gender politics of the scene are striking: The attack on the mother pig calls out for careful analysis. The boys are, for example, “wedded to her in lust” and climactically “heavy and fulfilled upon her” at the moment of her killing. What point is William Golding trying to make, here and elsewhere in the novel, about the nature of these young men and the ways in which they turn to and relish in aggression and violence? Key Question: What is the relationship between aggression and gender? © 2015 The New York Times Company
by Linda Geddes OUR personality literally shapes our world. It helps determine how many friends we have, which jobs we excel in and how we cope with adversity. Now it seems it may even play a role in our health – and not just in terms of any hypochondriac tendencies we harbour, but also how prone our bodies are to getting sick in the first place. It is a provocative idea but one that has been steadily gaining traction. We think of conscientiousness, for example, as a positive trait because it suggests caution, careful planning and an aversion to potential danger. But could it also be a symptom of underlying weakness in the immune system? That's one interpretation of a study published last month that sought to pick apart the links between personality traits and the immune system. It found that highly conscientious people had lower levels of inflammation; an immune response that helps the body fight infection and recover from injury. Highly extrovert people had higher levels. This may mean that extroverts are more physically robust – at least while they're young. While this sounds like good news, there's also a downside since sustained inflammation over a lifetime may leave you vulnerable to diabetes, atherosclerosis and cancer. "The biggest take-home message is that what happens in our health is connected to what happens in our heads and what happens in our lives," says Steven Cole at the University of California in Los Angeles (UCLA), who supervised the research. © Copyright Reed Business Information Ltd.
Link ID: 20510 - Posted: 01.22.2015
By BENEDICT CAREY The surge of emotion that makes memories of embarrassment, triumph and disappointment so vivid can also reach back in time, strengthening recall of seemingly mundane things that happened just beforehand and that, in retrospect, are relevant, a new study has found. The report, published Wednesday in the journal Nature, suggests that the television detective’s standard query — “Do you remember any unusual behavior in the days before the murder?” — is based on solid brain science, at least in some circumstances. The findings fit into the predominant theory of memory: that it is an adaptive process, continually updating itself according to what knowledge may be important in the future. The new study suggests that human memory has, in effect, a just-in-case file, keeping seemingly trivial sights, sounds and observations in cold storage for a time in case they become useful later on. But the experiment said nothing about the effect of trauma, which shapes memory in unpredictable ways. Rather, it aimed to mimic the arousals of daily life: The study used mild electric shocks to create apprehension and measured how the emotion affected memory of previously seen photographs. In earlier work, researchers had found plenty of evidence in animals and humans of this memory effect, called retroactive consolidation. The new study shows that the effect applies selectively to related, relevant information. “The study provides strong evidence for a specific kind of retroactive enhancement,” said Daniel L. Schacter, a professor of psychology at Harvard who was not involved in the research. “The findings go beyond what we’ve found previously in humans.” © 2015 The New York Times Company
By Rachel Feltman Fear is one of our most basic evolutionary instincts, a sudden physical jolt to help us react to danger more quickly. In the modern world, fear often seems excessive -- in the absence of wild animals to flee, we're left screaming over roller coasters and scary movies. But for at least one woman, fear is unobtainable. And while she lives a normal life, her fearlessness is actually a handicap. The researchers who study her keep her closely guarded, using the code-name "SM" when publishing papers about her brave brainpower. And until this year, she'd never been interviewed. "Tell me what fear is," Tranel began. "Well, that's what I'm trying to -- to be honest, I truly have no clue," SM said, her voice raspy. That's actually a symptom of the condition that stole fear from her. Urbach-Wieth disease, which is characterized by a hoarse voice, small bumps around the eyes, and calcium deposits in the brain is rare in its own right -- only 400 people on the planet are known to have it -- but in SM's case, some of those brain-deposits happened to take over her amygdalae. These almond-shaped structures deep inside the brain are crucial to human fear response. And in SM's case, they've been totally calcified since she was a young woman. Now in her 40s, her fear-center is as good as gone. "It's a little bit as if you would go to this region and literally scoop it out," Antonio Damasio, another neuroscientist who studies SM, told "Invisibilia" hosts Lulu Miller and Alix Spiegel.
Link ID: 20504 - Posted: 01.21.2015
By Amy Ellis Nutt Scientists have discovered what a traumatic brain injury, or TBI, suffered by a quarter-million combat veterans of Iraq and Afghanistan looks like, and it’s unlike anything they’ve seen before: a honeycomb pattern of broken connections, primarily in the frontal lobes, our emotional control center and the seat of our personality. “In some ways it’s a 100-year-old problem,” said Vassilis Koliatsos, a Johns Hopkins pathologist and neuropsychiatrist. He was referring to the shell-shock victims of World War I, tens of thousands of soldiers who returned home physically sound but mentally wounded, haunted by their experiences and unable to fully resume their lives. “When we started shelling each other on the Western Front of World War I, it created a lot of sick people . . . . [In a way,] we’ve gone back to the Western Front and created veterans who come back and do poorly, and we’re back to the Battle of the Somme,” he said. “They have mood changes, commit suicide, substance abuse, just like in World War I, and they really do poorly and can’t function. It’s a huge problem.” Many of the lingering symptoms of shell shock, or what today is known as neurotrauma, are the same as they were a century ago. Only the nature of the blast has changed, from artillery to improvised explosive devices. Koliatsos and colleagues, who published their findings in the journal Acta Neuropathologica Communications in November, examined the brains of five recent U.S. combat veterans, all of whom suffered a traumatic brain injury from an IED but died of unrelated causes back home. Their controls included the brains of people with a history of auto accidents and of those with no history of auto accidents or TBI. Koliatsos says he was prompted to do this study because he is both a pathologist and a neuropsychiatrist, and he sees many TBI cases, both in veterans and in young people with sports concussions.
By Tia Ghose Being around strangers can cause people stress and, in turn, make them less able to feel others' pain, new research suggests. But giving people a drug that blocks the body's stress response can restore that sense of empathy, scientists said. What's more, the same effect shows up in both humans and mice. "In some sense, we've figured out what to do about increasing empathy as a practical matter," said Jeffrey Mogil, a neuroscientist at McGill University in Montreal. "We've figured out what stops it from happening and, therefore, the solution to make it happen more between strangers." Decreasing stress by doing a shared activity could be a simple way to increase empathy between people who don't know each other, the findings suggest. Past studies had found that mice seemed to feel the pain of familiar mice but were less responsive to foreign mice. Other studies found that, in both humans and mice, stress levels tended to rise around strangers. To see how stress and empathy are connected, Mogil and his colleagues placed two mice together in a cage, then inflicted a painful stimulus on one of them. When the mice were cage mates, the unaffected mouse showed more signs of pain than when they were strangers. But when the team gave the mice a drug called metyrapone, which blocks the formation of the stress hormone cortisol, the mice responded equally to the strangers' pain.
Link ID: 20491 - Posted: 01.17.2015
by Bethany Brookshire Drugs that treat anxiety can be real downers. While they may help you feel less anxious, drugs such as Valium and Xanax can leave you drowsy and unfocused. Long-term use of these compounds, a class of drugs called the benzodiazepines, can lead to dependence and tolerance. And patients often need higher and higher doses to calm their anxiety. Getting off the drugs requires careful weaning to avoid insomnia, tremors and other nasty withdrawal effects. But Subhashis Banerjee and colleagues at the Scripps Research Institute in Jupiter, Fla., have identified a potential new target for anti-anxiety drugs that avoids the drowsiness and other side effects that come with the standard treatments. The target is an integral part of the body’s internal clock, and in tests in mice, compounds aimed at it reduced measures of anxiety while keeping the mice awake. The possibilities show how basic science questions, such as how the body produces sleep and internal rhythms, could have clinical applications. But it’s important to remember that it’s a long way between mice and people. The proteins REV-ERB alpha and REV-ERB beta are found in cell nuclei throughout the body. These proteins are receptors that sense levels of heme, subsections of chemicals in the body containing iron atoms. Levels of heme rise and fall based on a cell’s activity. REV-ERB responds to these heme level changes by controlling the activation of genes within the cell’s nucleus that govern the cell’s 24-hour internal clock. This circadian rhythm plays an important role in controlling our sleep. © Society for Science & the Public 2000 - 2015.
by Jessica Hamzelou YOU'RE not imagining the pain. But your brain might be behind it, nonetheless. For the first time, it is possible to distinguish between brain activity associated with pain from a physical cause, such as an injury, and that associated with pain linked to your state of mind. A fifth of the world's population is thought to experience some kind of chronic pain – that which has lasted longer than three months. If the pain has no clear cause, people can find themselves fobbed off by doctors who they feel don't believe them, or given ineffective or addictive painkillers. But a study led by Tor Wager at the University of Colorado, Boulder, now reveals that there are two patterns of brain activity related to pain. One day, brain scans could be used to work out your relative components of each, helping to guide treatment. "Pain has always been a bit of a puzzle," says Ben Seymour, a neuroscientist at the University of Cambridge. Hearing or vision, for example, can be traced from sensory organs to distinct brain regions, but pain is more complex, and incorporates thoughts and emotions. For example, studies have linked depression and anxiety to the development of pain conditions, and volunteers put in bad moods have a lower tolerance for pain. So does this mean we can think our way into or out of pain? To find out, Wager and his colleagues used fMRI to look at the brain activity of 33 healthy adults while they were feeling pain. First, the team watched the changing activity as they applied increasing heat to the volunteers' arms. As the heat became painful, a range of brain structures lit up. The pattern was common to all the volunteers, so Wager's team called it the neurologic pain signature. © Copyright Reed Business Information Ltd.
By Richard Leiby NEWPORT BEACH, Calif. — The headquarters of Oakley, a maker of recreational and military gear, looks as if it belongs in a war zone. It’s a massive bunker with exposed steel pipes, girders and blast walls. Even the dais in the auditorium is armored. But on a recent afternoon, the talk inside the building, set atop an arid, inland hillside in Orange County, is not about fighting wars but about caring for warriors. Doctors, scientists and veterans approach the podium at a conference to present some of the latest tools to help vets recover from wounds both mental and physical: bionics, virtual reality, magnetic waves. A session called “Healing the Warrior Brain” features a trim, bleach-blond former Army staff sergeant named Jonathan Warren, who recounts on video his struggle with post-traumatic stress disorder after combat in Iraq. His flashbacks, panic attacks and booze benders were well chronicled: For a year, the Los Angeles Times tracked Warren’s efforts to find peace, including via Department of Veterans Affairs therapy. It didn’t work, he says. But now a different Jon Warren is here to say that he is finally free of symptoms, one year after that 2013 story ran. No longer does his worst memory of the Iraq war — failing to rescue his best friend, who nearly burned to death after their Humvee hit a roadside bomb in 2006 — grasp his psyche and inflict guilt. That’s because of a revolutionary new treatment that retuned his brain, he says, and set “my frequencies right.” Now he’s able to proudly embrace his military service, “to keep the memory, to be able to go there,” Warren tells the audience, “and not be controlled by it.”
Link ID: 20474 - Posted: 01.13.2015
By Nicholas Weiler A friend can make even the shiest creature bold. Rats usually fear strange open spaces, but having a companion by their side makes the rodents more intrepid, scientists report in the current issue of Animal Cognition. Researchers tracked rats’ exploration of a large, unfamiliar room, first alone, then again 2 days later either alone or paired with a familiar cagemate. On their own, rats made short, hesitant forays into the open space before darting back to huddle by the door. Solitary rats’ anxiety in the room didn’t improve on their second visit. But adding a friend, even one who’d never seen the room before, gave the pair the confidence to actively explore, covering 50% more ground and running significantly faster than the control rats. And exploring with company seemed to boost the rats’ sense of security permanently. Placed in the room a third time, once more alone, the socialized rats boldly explored more new places than ever, while solo rats continued to cower. This illustrates that for communal animals like rats—and perhaps humans—friendship can be the best antidote to fear. © 2015 American Association for the Advancement of Scienc
Link ID: 20462 - Posted: 01.10.2015
By Susan Milius Whole scientific careers have gone into understanding why a harmless handful of fluff like a California ground squirrel taunts rattlesnakes. Now Rulon Clark and his team at San Diego State University are exploring the puzzle of why the squirrels also seem to taunt rocks, sticks and the occasional shrub. On spotting a snake, a California ground squirrel (Otospermophilus beecheyi) stares and sniffs, or if the snake is uncoiled, may even kick sand at it. And in bursts, the squirrel flags its tail left and right “like a windshield wiper,” Clark says. A rattler can strike a target 30 centimeters away in less than 70 milliseconds. But ground squirrels twist and dodge fast enough to have a decent chance of escape. Also, adult squirrels from snake country have evolved some resistance to venom. So taunting is worth the risks as a signal to neighboring squirrels and to the snake that its ambush attempt has been discovered. After getting publicly and lengthily squirreled, snakes often just slip away. Yet the squirrels also nyah-nyah tail flag at places where snakes might be but aren’t. To see if flagging indicates wariness, Clark and his colleagues built a squirrel startler that shoots out a cork using the classic spring that launches gag snakes out of cans (see video below). At spots with no sign of real snakes, squirrels mostly nibbled seeds in apparent tranquility with only a rare tail flag. The pop of a cork typically sent these squirrels scampering off on four speed-blurred paws. © Society for Science & the Public 2000 - 2014.