Chapter 16. None
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By Virginia Morell After defeating other males in boxing matches and winning a territorial roost—and a bevy of females—a male Seba’s short-tailed bat (Carollia perspicillata, pictured) might think his battles for reproductive rights are over. But the defeated males of this neotropical species have a trick up their sleeve: clandestine matings with willing females. The tactic works, and now researchers know why. Scientists studied bats in a captive colony in Switzerland, removing alpha males from their harems for 3 days, and examining their sperm—as well as that of their rivals. A previous study showed that the sneaky males have faster, longer lived sperm, which gives them a leg-up on the alpha male. Researchers had suspected this was because the sneakers produced this supersperm to compete. But the new study finds that after the 3 days of abstinence, the alpha male’s sperm is as agile and vigorous as that of his rivals. Thus, the team reports today in the Journal of Experimental Biology, the sneaky males aren’t generating special sperm—they just mate less, so their sperm is in better shape when it comes time to race to the egg. © 2016 American Association for the Advancement of Science.
By Gretchen Reynolds Young rats prone to obesity are much less likely to fulfill that unhappy destiny if they run during adolescence than if they do not, according to a provocative new animal study of exercise and weight. They also were metabolically healthier, and had different gut microbes, than rats that keep the weight off by cutting back on food, the study found. The experiment was done in rodents, not people, but it does raise interesting questions about just what role exercise may play in keeping obesity at bay. For some time, many scientists, dieting gurus and I have been pointing out that exercise by itself tends to be ineffective for weight loss. Study after study has found that if overweight people start working out but do not also reduce their caloric intake, they shed little if any poundage and may gain weight. The problem, most scientists agree, is that exercise increases appetite, especially in people who are overweight, and also can cause compensatory inactivity, meaning that people move less over all on days when they exercise. Consequently, they wind up burning fewer daily calories, while also eating more. You do the math. But those discouraging studies involved weight loss. There has been much less examination of whether exercise might help to prevent weight gain in the first place and, if it does, how it compares to calorie restriction for that purpose. So for the new study, which was published last week in Medicine & Science in Sports & Exercise, researchers at the University of Missouri in Columbia and other schools first gathered rats from a strain that has an inborn tendency to become obese, starting in adolescence. (Adolescence is also when many young people begin to add weight.) © 2016 The New York Times Company
Link ID: 22178 - Posted: 05.04.2016
By Helen Briggs BBC News The Labrador retriever, known as one of the greediest breeds of dog, is hard-wired to overeat, research suggests. The dog is more likely to become obese than other breeds partly because of its genes, scientists at Cambridge University say. The gene affected is thought to be important in controlling how the brain recognises hunger and the feeling of being full after eating. The research could help in the understanding of human obesity. "About a quarter of pet Labradors carry this gene [difference]," lead researcher Dr Eleanor Raffan told the BBC. "Although obesity is the consequence of eating more than you need and more than you burn off in exercise, actually there's some real hard-wired biology behind our drive to eat," she added. Lifestyle factors Canine obesity mirrors the human obesity epidemic, with lifestyle factors such as lack of exercise and high-calorie food both implicated - as well as genetics. As many as two in three dogs (34-59%) in rich countries are now overweight. The Labrador has the highest levels of obesity and has been shown to be more obsessed with food than other breeds. Researchers screened more than 300 Labradors kept as pets or assistance dogs for known obesity genes in the study, published in the journal Cell Metabolism. The international team found that a change in a gene known as POMC was strongly linked with weight, obesity and appetite in Labradors and Flat-Coated retrievers. In both breeds, for each copy of the gene carried, the dog was on average 2kg heavier. Other breeds of dog - from the Shih Tzu to the Great Dane - were also screened, but the genetic difference was not found. However, the variation was more common in Labradors working as assistance dogs, which the researchers say might be because these dogs are easier to train by rewarding with food. © 2016 BBC.
By Sarah Kaplan The ancient Greeks spoke of a mythological society composed entirely of warrior women. The medieval traveler John Mandeville wrote of a place whose female rulers "never would suffer man to dwell amongst them." "Paradise Island," home of Wonder Woman, was a feminist utopia where no one with a Y chromosome was allowed. Sadly, those places only exist in fiction. But something like them does exist in the real world. It's in a wetland in rural Ohio. And it's full of salamanders. "They’re pretty incredible," said Robert Denton, a biologist at Ohio State who studies an unusual group of salamander species that literally don't need men. These creatures – all female – reproduce by cloning themselves. To keep their gene pool diverse, they sometimes "steal" sperm left behind on trees and leaves by male salamanders of other species and incorporate that DNA into their offspring. Most sexually reproducing organisms have two sets of chromosomes to make up their genome – one from each parent. But one of these strange salamanders can have between two and five times that much genetic material lying in wait within her cells. It's as if they have multiple genomes to fall back on, and that's made them incredibly successful. "Polyploid" salamanders have been around some 6 million years, Denton said — far longer than most other animal species that reproduce asexually. Since a lack of diversity means having a smaller arsenal of genetic variation to fall back on when living conditions change, these groups usually go extinct relatively quickly. © 1996-2016 The Washington Post
by Susan Milius There’s nothing like a guy doing all the child care to win female favor, even among giant water bugs. Thumbnail-sized Appasus water bugs have become an exemplar species for studying paternal care. After mating, females lay eggs on a male’s back and leave him to swim around for weeks tending his glued-on load. For an A. major water bug, lab tests show an egg burden can have the sweet side of attracting more females, researchers in Japan report May 4 in Royal Society Open Science. Given a choice of two males, females strongly favored, and laid more eggs on, the one already hauling around 10 eggs rather than the male that researchers had scraped eggless. Females still favored a well-egged male even when researchers offered two males that a female had already considered, but with their egg-carrying roles switched from the previous encounter. That formerly spurned suitor this time triumphed. A similar preference, though not as clear-cut, showed up in the slightly smaller and lighter A. japonicus giant water bug. “We conclude that sexual selection plays an important role in the maintenance of elaborate paternal care,” says study coauthor Shin-ya Ohba of Nagasaki University. © Society for Science & the Public 2000 - 2016
By Emily Benson Baby birds are sometimes known to shove their siblings out of the nest to gain their parents’ undivided attention, but barn owl chicks appear to be more altruistic. Scientists recorded the hissing calls of hungry and full barn owl nestlings (Tyto alba, pictured), then played the sounds back to single chicks settled in nests stocked with mice. The young owls that heard the squawks of their hungry kin delayed eating each rodent by an average of half an hour; those that heard cries indicating their invisible nest-mate was full ate the mice more quickly. The findings suggest that barn owl chicks give hungrier siblings a chance to eat first even when the nest is full of food, the researchers will report in an upcoming issue of Behavioral Ecology and Sociobiology. So is it true altruism? Maybe not. Nestlings may share food in exchange for help with grooming or to get the first crack at a later meal, the team says, suggesting a possible ulterior motive. © 2016 American Association for the Advancement of Science
Link ID: 22174 - Posted: 05.04.2016
Laura Sanders Iron, says aging expert Naftali Raz, is like the Force. It can be good or bad, depending on the context. When that context is the human brain, though, scientists wrangle over whether iron is a dark force for evil or a bright source of support. Some iron is absolutely essential for the brain. On that, scientists agree. But recent studies suggest to some researchers that too much iron, and the chemical reactions that ensue, can be dangerous or deadly, especially to nerve cells in the vulnerable brain area that deteriorates with Parkinson’s disease. Yet other work raises the possibility that those cells die because of lack of iron, rather than too much. “There are a lot of surprises in this field,” says iron biologist Nancy Andrews of Duke University. The idea that too much iron is dangerous captivates many researchers, including analytical neurochemist Dominic Hare of the University of Technology Sydney. “All of life is a chemical reaction,” he says, “so the start of disease is a chemical reaction as well.” And as Raz points out, reactions involving iron are both life-sustaining and dangerous. “Iron is absolutely necessary for conducting the very fundamental business in every cell,” says Raz, of Wayne State University in Detroit. It helps produce energy-storing ATP molecules. And that’s a dirty job, throwing off dangerous free radicals that can cause cellular mayhem as energy is made. But those free radicals are not the most worrisome aspect of iron, Hare believes. “The reaction that is much more dangerous is the reaction you get when iron and dopamine come together,” he says. © Society for Science & the Public 2000 - 2016.
Link ID: 22173 - Posted: 05.03.2016
By Karen Weintraub The four members of Asperger’s Are Us decided a long time ago that their main goal would be to amuse themselves. But after nearly a decade of laughing and writing punch lines together, Asperger’s Are Us, which is probably the only comedy troupe made up of people on the autism spectrum, is on the cusp of comedic success. A documentary about the group premiered at the SXSW conference in Austin in March and was recently sold to Netflix. The troupe is also preparing for its first national tour this summer. Comedy might be a surprising choice for someone with Asperger’s syndrome, since stereotypically, people with autism are generally regarded as socially awkward loners. But the four men in the group bonded at summer camp 11 years ago, when one was a counselor and the other three were campers, and are clearly great friends. An “Aspergers Are Us” performance from 2011. Talking recently via Skype, Noah Britton, the former counselor, settles giant black rabbit ears onto his head. Jack Hanke, another member of the troupe, dons his favorite sombrero – the black one he took with him to Oxford University during his recent junior year abroad – accessorized with a red sombrero on top. They slip into their usual banter when asked what they thought of the film, named for the group, which will be shown publicly for the first time on Friday at the Somerville Theater outside of Boston. “I liked the four weird guys in it,” Mr. Britton said. “It was better than ‘Jaws 2,’ but not as good as ‘Jaws 3,’” Mr. Hanke insisted. “I found it kind of annoying myself,” added Ethan Finlan, another member of the group. The fourth member, who changed his first name to New Michael to distinguish himself from his father, Michael Ingemi, didn’t want to join the call. © 2016 The New York Times Company
Link ID: 22169 - Posted: 05.03.2016
By GINA KOLATA Danny Cahill stood, slightly dazed, in a blizzard of confetti as the audience screamed and his family ran on stage. He had won Season 8 of NBC’s reality television show “The Biggest Loser,” shedding more weight than anyone ever had on the program — an astonishing 239 pounds in seven months. When he got on the scale for all to see that evening, Dec. 8, 2009, he weighed just 191 pounds, down from 430. Dressed in a T-shirt and knee-length shorts, he was lean, athletic and as handsome as a model. “I’ve got my life back,” he declared. “I mean, I feel like a million bucks.” Mr. Cahill left the show’s stage in Hollywood and flew directly to New York to start a triumphal tour of the talk shows, chatting with Jay Leno, Regis Philbin and Joy Behar. As he heard from fans all over the world, his elation knew no bounds. But in the years since, more than 100 pounds have crept back onto his 5-foot-11 frame despite his best efforts. In fact, most of that season’s 16 contestants have regained much if not all the weight they lost so arduously. Some are even heavier now. Yet their experiences, while a bitter personal disappointment, have been a gift to science. A study of Season 8’s contestants has yielded surprising new discoveries about the physiology of obesity that help explain why so many people struggle unsuccessfully to keep off the weight they lose. Kevin Hall, a scientist at a federal research center who admits to a weakness for reality TV, had the idea to follow the “Biggest Loser” contestants for six years after that victorious night. The project was the first to measure what happened to people over as long as six years after they had lost large amounts of weight with intensive dieting and exercise. © 2016 The New York Times Company
Link ID: 22168 - Posted: 05.02.2016
Patricia Neighmond Hoping to keep your mental edge as you get older? Look after your heart, a recent analysis suggests, and your brain will benefit, too. A research team led by Hannah Gardener, an epidemiologist at the University of Miami, analyzed a subset of data from the Northern Manhattan Study, a large, ongoing study of risk factors for stroke among whites, blacks and Hispanics living in the Washington Heights neighborhood of New York City. The scientists wanted to see how people in their 60s and 70s would do on repeated tests of memory and mental acuity six years later — and, specifically, what sort of subtle differences a heart-healthy lifestyle might make to the brain, beyond the prevention of strokes. Their findings appear in a recent issue of the Journal of the American Heart Association. In this particular study, the researchers started with more than a thousand people who'd had their cardiovascular health assessed using measures that the American Heart Association has dubbed Life's Simple 7. These seven factors known to benefit the heart and blood vessels include maintaining a normal body weight and good nutrition, not smoking, getting exercise regularly and keeping blood pressure, cholesterol and blood sugar levels under control. To measure thinking skills, Gardener's team used a variety of tests of memory, judgement, the ability to plan, mental quickness and other sorts of problem solving. The results were striking: Across all demographic groups, the people who had higher scores on the measures of cardiovascular health did better on the mental tests than those who scored low. © 2016 npr
Link ID: 22167 - Posted: 05.02.2016
By Scott Barry Kaufman "Just because a diagnosis [of ADHD] can be made does not take away from the great traits we love about Calvin and his imaginary tiger friend, Hobbes. In fact, we actually love Calvin BECAUSE of his ADHD traits. Calvin’s imagination, creativity, energy, lack of attention, and view of the world are the gifts that Mr. Watterson gave to this character." -- The Dragonfly Forest In his 2004 book "Creativity is Forever", Gary Davis reviewed the creativity literature from 1961 to 2003 and identified 22 reoccurring personality traits of creative people. This included 16 "positive" traits (e.g., independent, risk-taking, high energy, curiosity, humor, artistic, emotional) and 6 "negative" traits (e.g., impulsive, hyperactive, argumentative). In her own review of the creativity literature, Bonnie Cramond found that many of these same traits overlap to a substantial degree with behavioral descriptions of Attention Deficit Hyperactive Disorder (ADHD)-- including higher levels of spontaneous idea generation, mind wandering, daydreaming, sensation seeking, energy, and impulsivity. Research since then has supported the notion that people with ADHD characteristics are more likely to reach higher levels of creative thought and achievement than people without these characteristics (see here, here, here, here, here, here, here, here, here, and here). Recent research by Darya Zabelina and colleagues have found that real-life creative achievement is associated with the ability to broaden attention and have a “leaky” mental filter-- something in which people with ADHD excel. © 2016 Scientific American
Link ID: 22166 - Posted: 05.02.2016
By ERICA GOODE Horses snooze in their stalls. Fish take their 40 winks floating in place. Dogs can doze anywhere, anytime. And even the lowly worm nods off now and then. All animals, most scientists agree, engage in some form of sleep. But the stages of sleep that characterize human slumber had until now been documented only in mammals and birds. A team of researchers in Germany announced in a report published on Thursday, however, that they had found evidence of similar sleep stages in a lizard: specifically, the bearded dragon, or Pogona vitticeps, a reptile native to Australia and popular with pet owners. Recordings from electrodes implanted in the lizards’ brains showed patterns of electrical activity that resembled what is known as slow-wave sleep and another pattern resembling rapid eye movement, or REM, sleep, a stage of deep slumber associated with brain activity similar to that of waking. Some researchers had argued that these stages were of relatively recent origin in evolutionary terms because they had not been found in more primitive animals like amphibians, fish, reptiles other than birds, and other creatures with backbones. But the new finding, said Gilles Laurent, director of the department of neural systems at the Max Planck Institute for Brain Research and the principal author of the study, “increases the probability that sleep evolved in all these animals from a common ancestor.” He added that it also raised the possibility that staged sleep evolved even earlier and that some version of it might exist in animals like amphibians or fish. The report appeared in Thursday’s issue of the journal Science. Other researchers said the study could help scientists understand more about the purpose and mechanisms of sleep. But the finding, they added, is bound to generate more controversy about whether the resting state of primitive animals is really the same as sleep, and whether the brain activity seen in a lizard can be compared to that in mammals. © 2016 The New York Times Company
Tina Hesman Saey To rewrite an Alanis Morissette song, the brain has a funny way of waking you up (and putting you to sleep). Isn’t it ionic? Some scientists think so. Changes in ion concentrations, not nerve cell activity, switch the brain from asleep to awake and back again, researchers report in the April 29 Science. Scientists knew that levels of potassium, calcium and magnesium ions bathing brain cells changed during sleep and wakefulness. But they thought neurons — electrically active cells responsible for most of the brain’s processing power — drove those changes. Instead, the study suggests, neurons aren’t the only sandmen or roosters in the brain. “Neuromodulator” brain chemicals, which pace neuron activity, can bypass neurons altogether to directly wake the brain or lull it to sleep by changing ion concentrations. Scientists hadn’t found this direct connection between ions and sleep and wake before because they were mostly focused on what neurons were doing, says neuroscientist Maiken Nedergaard, who led the study. She got interested in sleep after her lab at the University of Rochester in New York found a drainage system that washes the brain during sleep (SN: 11/16/13, p. 7).When measuring changes in the fluid between brain cells, Nedergaard and colleagues realized that ion changes followed predictable patterns: Potassium ion levels are high when mice (and presumably people) are awake, and drop during sleep. Calcium and magnesium ions follow the opposite pattern; they are higher during sleep and lower when mice are awake. © Society for Science & the Public 2000 - 2016
Link ID: 22163 - Posted: 04.30.2016
By Andy Coghlan “I’ve become resigned to speaking like this,” he says. The 17-year old boy’s mother tongue is Dutch, but for his whole life he has spoken with what sounds like a French accent. “This is who I am and it’s part of my personality,” says the boy, who lives in Belgium – where Dutch is an official language – and prefers to remain anonymous. “It has made me stand out as a person.” No matter how hard he tries, his speech sounds French. About 140 cases of foreign accent syndrome (FAS) have been described in scientific studies, but most of these people developed the condition after having a stroke. In the UK, for example, a woman in Newcastle who’d had a stroke in 2006 woke up with a Jamaican accent. Other British cases include a woman who developed a Chinese accent, and another who acquired a pronounced French-like accent overnight following a bout of cerebral vasculitis. But the teenager has had the condition from birth, sparking the interest of Jo Verhoeven of City University London and his team. Scans revealed that, compared with controls, the flow of blood to two parts of the boy’s brain were significantly reduced. One of these was the prefrontal cortex of the left hemisphere – a finding unsurprising to the team, as it is known to be associated with planning actions including speech. © Copyright Reed Business Information Ltd.
Link ID: 22161 - Posted: 04.30.2016
By n. r. kleinfield IT BEGAN WITH what she saw in the bathroom mirror. On a dull morning, Geri Taylor padded into the shiny bathroom of her Manhattan apartment. She casually checked her reflection in the mirror, doing her daily inventory. Immediately, she stiffened with fright. Huh? What? She didn’t recognize herself. She gazed saucer-eyed at her image, thinking: Oh, is this what I look like? No, that’s not me. Who’s that in my mirror? This was in late 2012. She was 69, in her early months getting familiar with retirement. For some time she had experienced the sensation of clouds coming over her, mantling thought. There had been a few hiccups at her job. She had been a nurse who climbed the rungs to health care executive. Once, she was leading a staff meeting when she had no idea what she was talking about, her mind like a stalled engine that wouldn’t turn over. “Fortunately I was the boss and I just said, ‘Enough of that; Sally, tell me what you’re up to,’” she would say of the episode. Certain mundane tasks stumped her. She told her husband, Jim Taylor, that the blind in the bedroom was broken. He showed her she was pulling the wrong cord. Kept happening. Finally, nothing else working, he scribbled on the adjacent wall which cord was which. Then there was the day she got off the subway at 14th Street and Seventh Avenue unable to figure out why she was there. So, yes, she had had inklings that something was going wrong with her mind. She held tight to these thoughts. She even hid her suspicions from Mr. Taylor, who chalked up her thinning memory to the infirmities of age. “I thought she was getting like me,” he said. “I had been forgetful for 10 years.”
Link ID: 22160 - Posted: 04.30.2016
By PAM BELLUCK Alzheimer’s disease can seem frightening, mysterious and daunting. There are still a lot of unknowns about the disease, which afflicts more than five million Americans. Here are answers to some common questions: Sometimes I forget what day it is or where I put my glasses. Is this normal aging, or am I developing Alzheimer’s? Just because you forgot an item on your grocery list doesn’t mean you are developing dementia. Most people have occasional memory lapses, which increase with age. The memory problems that characterize warning signs of Alzheimer’s are usually more frequent, and they begin to interfere with safe or competent daily functioning: forgetting to turn off the stove, leaving home without being properly dressed or forgetting important appointments. Beyond that, the disease usually involves a decline in other cognitive abilities: planning a schedule, following multistep directions, carrying out familiar logistical tasks like balancing a checkbook or cooking a meal. It can also involve mood changes, agitation, social withdrawal and feelings of confusion, and can even affect or slow a person’s gait. How is Alzheimer’s diagnosed? Diagnosing Alzheimer’s usually involves a series of assessments, including memory and cognitive tests. Clinicians will also do a thorough medical work-up to determine whether the thinking and memory problems can be explained by other diagnoses, such as another type of dementia, a physical illness or side effects from a medication. Brain scans and spinal taps may also be conducted to check for corroborating evidence like the accumulation of amyloid, the hallmark protein of Alzheimer’s, in the brain or spinal fluid. The cause is unknown for most cases. Fewer than 5 percent of cases are linked to specific, rare gene mutations. Those are usually early-onset cases that develop in middle age. © 2016 The New York Times Company
Link ID: 22159 - Posted: 04.30.2016
By Adam Bear It happens hundreds of times a day: We press snooze on the alarm clock, we pick a shirt out of the closet, we reach for a beer in the fridge. In each case, we conceive of ourselves as free agents, consciously guiding our bodies in purposeful ways. But what does science have to say about the true source of this experience? In a classic paper published almost 20 years ago, the psychologists Dan Wegner and Thalia Wheatley made a revolutionary proposal: The experience of intentionally willing an action, they suggested, is often nothing more than a post hoc causal inference that our thoughts caused some behavior. The feeling itself, however, plays no causal role in producing that behavior. This could sometimes lead us to think we made a choice when we actually didn’t or think we made a different choice than we actually did. But there’s a mystery here. Suppose, as Wegner and Wheatley propose, that we observe ourselves (unconsciously) perform some action, like picking out a box of cereal in the grocery store, and then only afterwards come to infer that we did this intentionally. If this is the true sequence of events, how could we be deceived into believing that we had intentionally made our choice before the consequences of this action were observed? This explanation for how we think of our agency would seem to require supernatural backwards causation, with our experience of conscious will being both a product and an apparent cause of behavior. In a study just published in Psychological Science, Paul Bloom and I explore a radical—but non-magical—solution to this puzzle. © 2016 Scientific America
Link ID: 22158 - Posted: 04.30.2016
By SABRINA TAVERNISE Taking a stance sharply at odds with most American public health officials, a major British medical organization urged smokers to switch to electronic cigarettes, saying they are the best hope in generations for people addicted to tobacco cigarettes to quit. The recommendation, laid out in a report published Thursday by the Royal College of Physicians, summarizes the growing body of science on e-cigarettes and finds that their benefits far outweigh the potential harms. It concludes resoundingly that, at least so far, the devices are helping people more than harming them, and that the worries about them — including that using them will lead young people to eventually start smoking traditional cigarettes — have not come to pass. “This is the first genuinely new way of helping people stop smoking that has come along in decades,” said John Britton, director of the U.K. Center for Tobacco and Alcohol Studies at the University of Nottingham, who led the committee that produced the report. E-cigarettes, he said, “have the potential to help half or more of all smokers get off cigarettes. That’s a huge health benefit, bigger than just about any medical intervention.” That conclusion is likely to be controversial in the United States, where arguments about e-cigarettes have jolted the traditionally low-key public health community. E-cigarettes deliver nicotine without the harmful tar and chemicals that cause cancer. Some public health experts see e-cigarettes as the first real chance in years for 40 million addicted Americans to quit. But others, including the federal Centers for Disease Control and Prevention, have focused on the potential dangers of e-cigarettes, for example that they could extend smoking habits, that they could be a gateway to traditional cigarettes for children, or that their vapor could to turn out to have long-term health effects. © 2016 The New York Times Company
Keyword: Drug Abuse
Link ID: 22153 - Posted: 04.28.2016
Nicola Davis Benedict Cumberbatch’s deep and booming voice might have made him a hit among women, but a low pitch is more likely to have evolved to intimidate other men, new research suggests. When both heterosexual men and women were played recordings of male voices, the deeper tones were hailed by men as sounding more dominant. While the deeper voices were judged to be more attractive by female listeners, the effect was weaker, the researchers report. “If you look at what men’s traits look like they are designed for, they look much better designed for intimidating other males than for attracting females,” said David Puts of Pennsylvania State University, who led the study. Published in Proceedings of the Royal Society B: Biological Sciences, the three-part study by an international team of scientists explored the links between voice pitch and mating systems, attractiveness and, for males only, perceived dominance. A formula for the perfect voice? Read more In the first leg of the research, the scientists turned their attention to primates encompassing Old and New World monkeys, as well as humans and other apes, to explore differences in “fundamental frequency” between males and females of each species - the aspect of the voice that is perceived as pitch. After selecting 1721 recordings, they found large differences were more common in polygynous species - where males mate with more than one female - than monogamous ones. That, they say, could be because in polygynous species, competition between males is greater - hence a male with a lower-pitched voice deemed to be intimidating could have the edge in securing a mate. Intriguingly, the researchers found that among the apes humans showed the greatest difference in pitch between the sexes, suggesting our ancestors were not searching for “the one” but were polygynous - a situation Puts still believes to be the case. © 2016 Guardian News and Media Limited
by Bethany Brookshire Interviewing for a new job is filled with uncertainty, and that uncertainty fuels stress. There’s the uncertainty associated with preparing for the interview — what questions will they ask me? What should I put in my portfolio? And then there’s the ambiguity when you’re left to stew. Did I get the job? Or did someone else? Scientists have recently shown that these two types of uncertainty — the kind we can prepare for, and the kind we’re just stuck with — are not created equal. The uncertainty we can’t do anything about is more stressful than the one we can. The results help show exactly what in our lives freaks us out — and why. But the findings also show a positive side to the stress we feel when not knowing what’s ahead — the closer our stress levels reflect the real ambiguity in the world, the better we perform in it. “There is a bias in the public perception” against stress, says Claus Lamm, a cognitive neuroscientist at the University of Vienna in Austria. But stress “prepares us to deal with environmental challenges,” he notes, preparing us to fight or flee, and it keeps us paying attention to our surroundings. For decades, scientists have been trying to figure out just what makes us stressed and why. It turns out that unpredictability is a great stressor. Studies in the 1960s and 1970s showed that rats and humans who can’t predict a negative effect (such as a small shock) end up more frazzled than those who can predict when a zap is coming. In a 2006 study, people zapped with unpredictable electric shocks to the hand rated the pain as more unpleasant than when they knew what to expect. © Society for Science & the Public 2000 - 2016.
Link ID: 22151 - Posted: 04.27.2016