A small study suggests that men are better able to resist food cravings than women, which researchers say could partially explain why more women than men are obese, and why women are more prone to overeating when they’re under emotional stress. In a new brain-scan study, researchers flashed tasty food in front of men and women who hadn’t eaten anything in at least 17 hours. Both were told to fight their hunger, but only men showed a drop in activity in brain regions involved in emotion and motivation [CNN]. However, some researchers say that it’s risky to generalize based on a study with just 23 test subjects.
In the study, which will be published in Proceedings of the National Academy of Sciences, researchers engaged their volunteers in a somewhat torturous experiment. They first surveyed the volunteers about their favorite foods: Did they favor pizza, chocolate cake, burgers, or fried chicken? Then they were asked to fast overnight. When they returned to the lab the next day, the subjects got PET brain scans while being subjected to a barrage of craving-inducing stimuli. They looked at pictures of their favorite food, smelled its aroma wafting in from the next room, and even tasted it with cotton swabs placed on their tongues.
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Men who want to know if they’d make it as day traders on Wall Street just have to look down at the fingers, according to a new study. The longer their ring fingers are in relation to their pointer fingers, the more likely they are to have what it takes to make millions on the trading floor. Previous research has found that the digit ratio reflects how much testosterone an unborn baby was exposed to in the womb. Those exposed to high levels of the hormone are more sensitive as adults to testosterone that creates feelings of confidence and encourages risk-taking, said study author John Coates [Bloomberg].
Coates has previously shown that traders who register the highest levels of testosterone in the morning make the most money through the course of the day, and this new study adds to the earlier work by suggesting that their advantage may have been innate, not learned. Although it may come as no surprise that testosterone could be a big player in the mano-a-mano world of Wall Street, the research offers the best evidence yet of the hormone’s role in determining which would-be Masters of the Universe will thrive. It also supports the growing recognition that biology plays a role in complex human behaviors, and that financial choices in particular are often less rational than economists appreciated [Washington Post].
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In a new study, most people willingly pulled a lever to deliver pain to others when instructed to do so, showing that little has changed in the near half-century since psychologist Stanley Milgram’s famous electric shock experiment. Milgram’s experiment revealed our propensity to do harm when encouraged by authority, a topic of great interest in the post-World War II years. A new iteration of the experiment (with added precautions) revealed that seven out of ten people will give painful electric shocks to another person as part of what they are told is a scientific investigation. “What we found is validation of the same argument—if you put people into certain situations, they will act in surprising, and maybe often even disturbing, ways,” [Reuters] says researcher Jerry Burger.
In the 1961 experiment, Yale University professor Milgram asked volunteers to deliver increasingly strong electric “shocks” to other people, who appeared to be test subjects but were really actors, if they answered certain questions incorrectly. Milgram found that, after hearing an actor cry out in pain at 150 volts, 82.5 percent of participants continued administering shocks, most to the maximum 450 volts [Reuters]. The results, now a fixture in psychology textbooks, suggested that people’s moral attitudes can be suppressed when they’re put in a situation of obedience. Although no actual shocks were delivered and the sounds of agony came from a tape-recording, many of the volunteers suffered stress from the task and replication of the experiments was deemed unethical.
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When a juror first makes a decision on the guilt of a defendant and then hands down a sentence, two entirely different regions of the brain are involved, a new brain imaging study has shown—and neither is as rational as we might want to believe. Researchers using functional MRI scans found that a brain in the process of making a decision about the guilt of another person looks a lot like the brain of a person deciding whether they themselves have been wronged; what’s more, decisions about punishment are linked to brain regions that process emotions. “Our judicial system based on third-party punishment is usually seen as cold and detached as opposed to … punishment by the victim of a crime,” [study coauthor René] Marois says. The new study shows that emotions play a part in impartial judgment too [Science News].
Judgments of the culpability of another person were linked to activity in the right dorsolateral prefrontal cortexes, researchers found; this region has previously been implicated in decisions of morality and fairness, as well as other functions unrelated to the law. When another team temporarily blocked [activity in this region] with a magnet, participants playing a financial game that tests trust failed to punish unfair offers. No-one expected that almost the same cognitive machinery kicks in when impartially making a decision about cheating and when you yourself are cheated [New Scientist], says study coauthor Owen Jones.
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It’s not just we humans who value consensus: A new study has shown that stickleback fish make better decisions when acting as a group than they do as individuals. Researchers set up a clever experiment in which the fish had to choose which leader to follow in the quest for food, giving them an option between a “good” choice and a “bad” choice. Based on earlier experiments, the study’s researchers had a pretty good idea about … stickleback preferences. Fat, evenly colored fish are regarded as healthy and strong, while scrawny fish mottled with black spots may be considered diseased. Coauthor Ashley Ward … says of these sticklebacks, “Fish like large leaders, well-fed leaders and unparasitized leaders” [Science News].
Researchers made a stickleback replica that looked healthy and fat as well as one that appeared bony and mottled, and put both into the fish tank. When shown the fish replicas, the other sticklebacks in the tank would approach and follow one of the two replicas, which were moved around by remote control. Following a certain fish would be their version of casting a ballot…. When just one fish chose its leader, the fish would make the right choice, picking the healthiest leader about 55 percent of the time. That number went up to 80 percent with the eight-fish electorate [LiveScience].
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People who feel that they lack control while participating in lab experiments are more likely to see patterns where none exist, researchers say, in a finding that helps explain persistent beliefs in superstitions and conspiracy theories. In a new study, researchers manipulated volunteers’ perception of control and then watched the insecure subjects find connections where none existed in an apparent attempt to restore a sense of order to the world.
In one experiment, researchers gave half the volunteers a feeling of powerlessness and confusion by randomly scoring them right and wrong (and mostly wrong) on a series of questions. Then the volunteers had to find patterns. In one task, they were asked to find faint images in grainy patterns of dots. Half of the pictures had images and the others were random dots. While people in both groups correctly spotted the images, the group that felt they lacked control from a previous part of the experiment also “saw” images in 43 percent of pictures that were not there [Reuters].
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Teenage boys with behavior problems may be able to blame their brain chemistry, according to a new study. Psychologists studied boys with a history of antisocial behavior and measured their levels of the hormone cortisol, which usually surges during stressful situations, causing people to focus and behave more cautiously. They found that the troubled boys didn’t have the normal cortisol spike when they were put under stress, suggesting that they weren’t getting a chemical signal to regulate their emotions and actions.
Researchers say the findings suggest that some bad behavior should be considered a form of mental illness. “Most research has looked at social factors like peer groups, family life and socioeconomic factors,” said [lead researcher] Graeme Fairchild…. “These findings basically indicate that antisocial behavior is probably more biologically based than many people recognize and is similar to conditions like depression and anxiety” [Reuters].
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In a finding that has particular relevance right now, as the American public looks for scapegoats for the current financial crisis, a new study has found that men with higher levels of testosterone are inclined to make riskier financial decisions. Just how much riskier? Those with 33 percent more testosterone than average men invested 10 percent more of their dough. The findings are based on saliva samples from 98 male Harvard students taken before they played an investment game with $250 in real money [Scientific American].
Researchers say they didn’t outright prove that it was Wall Street men’s hormones that got us into this mess, but that the evidence is strongly suggestive. “Although our findings do not address causality, we believe that testosterone may influence how individuals make risky financial decisions,” said researcher Coren Apicella…. A recent study also showed that stock market traders made more money on days when their testosterone levels were highest [LiveScience].
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Ever wondered what causes the spate of wild bidding in the last few minutes of an Ebay auction? Scientists say they now have answer: The irrational behavior is caused by people’s fear of losing, not their desire to win. While economists have recognized the concept of “loss aversion” for some time, a new set of experiments used brain scans and lab experiments to show how strongly the phenomenon plays out in auctions, and how it’s tied to overbidding.
In the first experiment, test subjects participated in either a lottery or an auction. During the games, scientists watched the responses of the subjects’ striata—the brain’s reward center—using functional magnetic resonance imaging (fMRI). The elation of winning was the same in both games, but the agony of defeat was crushing for losers of the auction. After auction, brain activity in the loser’s reward centers decreased substantially. But it hardly blipped when the person lost a lottery [Ars Technica]. What’s more, auction losers who had the steepest declines in striata activity were more likely to have overbid during the auction.
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It’s a demonstration of unconscious brain power: A new neuroscience study shows that people can make decisions based on input that is invisible to the conscious mind. Researchers say the findings aren’t evidence of the efficacy of subliminal messages, which have mostly been discredited. But there has been a more subtle phenomenon, billed as the foundation of intuition, where seasoned poker players may play more successfully because they can pick up subtle signals in the body language of their opponents – without consciously realising it – to work out if they are bluffing [Telegraph].
In the study, published in the journal Neuron [subscription required], test subjects were repeatedly shown brief abstract animations before being asked whether they wanted to take a gamble, which could either earn or lose them a small amount of money. The animations had hidden symbols that indicated whether the subject would win or lose on the subsequent bet; over time, test subjects got better at predicting whether they would win or not.
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People who say they’re undecided on a hot political topic may already have made up their minds; they just haven’t consciously realized it yet. A clever new study that measured unconscious positive and negative associations indicates that most undecided voters have already formed a preference for one position or candidate.
Experts say the findings may help explain why political polls can be so off-base, and why some people make up their minds in the voting booth with little sense of why they pulled the lever yeah or nay, blue or red [The New York Times]. Pollsters and politicians who think that undecided voters can still be swayed either way should take note, says lead researcher Bertram Gawronski.
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When a “new and improved” sign catches your eye and your hand starts to move towards the product, an ancient part of the brain called the ventral striatum is at work. Researchers say a new study shows that primitive portion of the brain is activated when people try something unfamiliar, which suggests that the impulse to seek out new things has conveyed an advantage ever since the early stages of evolution.
To conduct the study, which was published in the journal Neuron, researchers took brain scans of volunteers who were playing a game. The test subjects were shown cards and had to pick the one they thought had a monetary reward attached; after a few repetitions, they knew which cards were most likely to win them some money. Then researchers started introducing new cards and watched the reaction. “What we found is that people preferentially go for the ones they’ve never seen before,” [lead researcher Bianca] Wittmann says. Rather than stick with the familiar — a picture for which they’ve already figured out the probability of getting money — they’d rather take their chance on a new picture [ABC News].
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People may think they’re making up their own minds when they step into the voting booth on election day; they may think that the decision they make there is a product of careful reflection and personal values. But a new study suggests that voters may be swayed by the simplest factors, like the associations they have with the physical place where they vote. In the study, researchers showed that people who cast their votes in a school were more likely to support an education initiative.
“Seemingly innocuous factors can influence behavior,” said Jonah Berger, assistant professor of marketing at the Wharton School of the University of Pennsylvania, and the study’s lead author. “There is a connection between location and the thing people are voting on” [ABC News Medical Unit].
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Here’s one easy way to help avoid conflict and strife in your interactions with others: When you eat your three square meals a day, don’t skimp on the meats and cheeses.
Those foods contain high levels of the amino acid tryptophan, which the body needs to produce the neurotransmitter serotonin, a chemical in the brain that plays a role in regulating mood, aggression and social behavior. In a new study, test subjects with high serotonin levels responded less aggressively while making emotionally charged financial decisions in a test known as the ultimatum game.
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