Women cheat on men for their own needs but superb starling females stray from their mates for the sake of their chicks, according to recent Cornell research. This reasoning includes being able to know if mates are too ‘genetically similar’ for breeding.

That gives ‘doing it for the kids’ a whole new layer of meaning. The study found that superb starling females (Lamprotornis superbus) cheat on their mates based on these factors:

• Superb starlings are cooperative breeders, meaning breeding pairs get help in raising chicks from other family group members. Some females mate with subordinate males when they need help to raise their chicks. This additional male then acquires food and tends to the nestlings, which increases the chicks’ survival rates.
• The subordinate males get something from this also. Females often leave the group when young but most males live their entire lives with their families and, therefore, are usually related to the chicks. By helping the chicks survive, they pass on familial genes.
• Because family males are often around their entire lives, some females cheat with males outside their group if they sense their mates are too genetically similar to themselves. Mating with strangers increases their brood’s genetic diversity even though it does not give them additional help.

How do they know? No one is sure how females detect the genetic similarities between themselves and their mates, though other species of birds appear to adopt similar mating strategies.

Usually, if a female bird (or a human female) is caught cheating, the partner punishes her by doing less work in raising the chicks, or in extreme cases, leaves her to raise the chicks on her own. Not so with these starlings.

Superb starlings of East Africa are cooperative breeders and even if the female is caught cheating, she still may get help from other group members. Still, superb starlings tend to stray much less often than other cooperative breeders, despite the dual potential benefits for females in seeking extra-pair mates.

“In most avian cooperative breeders, 40 to 60 percent of offspring are a result of extra-pair matings, but in superb starlings, only about 14 percent of the offspring are fathered by other males,” said Rubenstein. No one knows why superb starling females have lower rates of cheating, but Rubenstein said it suggests that there may be less conflict between the sexes than in other species. He is currently researching this issue.

While it has long been known that males of many species cheat and mate widely to produce as many offspring as possible to spread their genes, the reasons behind female infidelity appear more complex. With this study and this species, “we can break down the reasons why superb starling females are not faithful to their mates and see that they have different extra-pair mating strategies,” said Rubenstein. “It adds a whole new layer of complexity to the story.”

Source: Cornell

Yes, you secretly like giving your money to the government. University of Oregon scientists have found that doing things like donating money to charity or even paying your taxes can give you the same sort of satisfaction you derive from feeding your own hunger pangs.

A cognitive psychologist and two economists gave 19 female participants $100 and then scanned their brains with functional magnetic resonance imaging (fMRI) as they watched their money go to the food bank through mandatory taxation, and as they made choices about whether to give more money voluntarily or keep it for themselves.

The participants lay on their backs in the fMRI scanner for an hour-long session and viewed the financial transfers on a computer screen. The scanner used a super-cooled magnet, carefully tuned radio waves and powerful computers to calculate what parts of the brain were active as subjects saw their money go to the food bank and made yes or no decisions on additional giving.

Researchers found that two evolutionarily ancient regions deep in the brain – the caudate nucleus and the nucleus accumbens – fired when subjects saw the charity get the money. The activation was even larger when people gave the money voluntarily, instead of just paying it as taxes. These brain regions are the same ones that fire when basic needs such as food and pleasures (sweets or social contact) are satisfied.

“The surprising element for us was that in a situation in which your money is simply given to others – where you do not have a free choice – you still get reward-center activity,” said Ulrich Mayr, a professor of psychology. “I don’t think that most economists would have suspected that. It reinforces the idea that there is true altruism – where it’s all about how well the common good is doing. I’ve heard people claim that they don’t mind paying taxes, if it’s for a good cause – and here we showed that you can actually see this going on inside the brain, and even measure it.

The study gives economists a novel look inside the brain during taxation, said co-author William T. Harbaugh, a UO professor of economics and member of the National Bureau of Economic Research in Cambridge, Mass. “To economists, the surprising thing about this paper is that we actually see people getting rewards as they give up money,” he said. “Neural firing in this fundamental, primitive part of the brain is larger when your money goes to a non-profit charity to help other people.”

“On top of that,” Harbaugh added, “people experience more brain activation when they give voluntarily – even though everything here is anonymous. That’s a very surprising result – and, to me, an optimistic one.”

However, this latter finding, which offers confirmation to the economic theory of “warm-glow” giving, doesn’t necessarily mean that taxes should be lowered and charity relied on more heavily, Harbaugh said. In a voluntary environment, he added, lots of people free-ride and donations fall.

The study, Mayr said, reflects the balancing act that every society must face. “What this shows to someone who designs tax policy is that taxes aren’t all bad,” he said. “Paying taxes can make citizens happy. People are, to varying degrees, pure altruists. On top of that they like that warm glow they get from charitable giving. Until now we couldn’t trace that in the brain.”

Neural activation from mandatory taxation, the researchers said, helps predict who will give. “We could call the people whose brains light up more when money goes to charity than to themselves altruists,” Mayr said. “The others are egoists. Based on what we saw in the experiments, we can use this classification to predict how much people are willing to give when the choice is theirs.”

There remain a lot of unanswered questions, Harbaugh said. “We show that people liked paying a tax that went to a food bank. But suppose the tax had been unfair. What then? Or suppose that people voted to make other people pay the tax, too? That would help other people even more, so would the voter get a bigger neural reward?”

Harbaugh, Mayr and co-author Dan Burghart, an economics graduate student, say they are not worried about the possibility that governments could use their method to monitor tax evasion, or charities could use it to figure out whom to ask for money. “To do this, we needed a $3 million scanner, some liquid helium and a few weeks of computer time,” Harbaugh said.

“If a participant moved her head,” Burghart added, “we had to start all over. It will be a while before this is built into cell phones.”

Source: University of Oregon

Eating low-calorie soup before a meal can help cut back on how much food and calories you eat at the meal, a new Penn State study shows. Results show that when participants in the study ate a first course of soup before a lunch entree, they reduced their total calorie intake at lunch (soup + entrée) by 20 percent, compared to when they did not eat soup.

“This study expands on previous studies about consuming lower-calorie soup as a way to reduce food intake,” says co-author Dr. Barbara Rolls, who holds the Guthrie Chair of Nutrition at Penn State. “Earlier work suggests that chunky soup may be the most filling type of soup, so the purpose of this study was to determine whether different forms of soup might have different effects on food intake. “

The study tested whether the form of soup and the blending of its ingredients also affected food intake and satiety. All of the soups tested in the study were made from identical ingredients: chicken broth, broccoli, potato, cauliflower, carrots and butter. However, the methods used to blend the ingredients varied, so that the form of the soup changed. Soups tested included separate broth and vegetables, chunky vegetable soup, chunky-pureed vegetable soup, and pureed vegetable soup.

While researchers thought that increasing the thickness or the amount of chewing required may have made certain forms of soup more filling, results of the study show that low-calorie soup is filling regardless of its form.

Julie Flood, a doctoral student in nutritional sciences at Penn State, and Rolls presented their findings today (May 1, 2007) at the Experimental Biology Conference in Washington, D.C.

“Consuming a first-course of low-calorie soup, in a variety of forms, can help with managing weight, as is shown in this research and earlier studies. Using this strategy allows people to get an extra course at the meal, while eating fewer total calories,” says Flood. “But make sure to choose wisely, by picking low-calorie, broth-based soups that are about 100 to 150 calories per serving. Be careful of higher-calorie, cream-based soups that could actually increase the total calories consumed.”

The concept of “Volumetrics” — eating a satisfying volume of food while controlling calories and meeting nutrient requirements — is based on a series of studies led by Rolls in her Laboratory for the Study of Human Ingestive Behavior. This spring, the paperback edition of her book, “The Volumetrics Eating Plan: Techniques and Recipes for Feeling Full on Fewer Calories” is being published by HarperCollins.

A unique pattern of gene expression observed in rats may be linked to a conditioned desire for food and excessive food intake, an article published today in BMC Biology suggests.

It’s well known that food-associated cues, such as advertising, can influence food intake. But the underlying neurobiology is far from clear. Craig A. Schiltz and colleagues from the University of Wisconsin Madison School of Medicine and Public Health, USA, created an experimental set up that allowed them to study patterns of gene expression linked to this motivational state - rats conditioned to expect a chocolate-flavoured treat in a particular environment, were subsequently denied their reward.

The research, conducted in the laboratory of Ann E. Kelly showed that expression of a handful of immediate early genes was increased in cortical, striatal, thalamic and hypothalamic brain regions. Food-related cues triggered dramatic changes in the functional connectivity of circuits involved in adaptive behaviour. For example, increased connectivity was seen between the cortex and two other regions - the amygdala and the striatum. Within the latter, there was a shift in activity from the outer shell to the inner core of the nucleus accumbens and an increased expression of the opioid-encoding proenkephalin gene.

Taken together, these results suggest that food-associated cues have a powerful influence on neuronal activity and gene expression in brain areas mediating complicated functions such as cognition and emotion, and more basic abilities such as arousal and energy balance. The pattern of activation differs from that elicited by neutral cues, and may well contribute to a conditioned motivational state that can lead to excessive food intake.

Source: “Food-associated cues alter forebrain functional connectivity as assessed with immediate early gene and proenkephalin expression” Craig A Schiltz, Quentin Z Bremer, Charles F Landry and Ann E Kelley