Long a subject of debate—and experiments with everything from yeast to mice—the question of whether a lower calorie diet increases life span while decreasing disease has a new smorgasbord of evidence.

A 20-year-long rhesus monkey study, released today in Science, found that monkeys that consumed 30 percent less calories than average peers were one third as likely to get a age-related disease and were likely to live longer. 

Of the monkeys in the trial, 80 percent of those on the restricted diet are still alive, whereas just half of those that ate as they pleased are still around.

Scientists have confirmed what pet owners have always suspected: our pooches may pout when they sense another pup is getting favorable treatment.

Researchers at the University of Vienna in Austria report today in the Proceedings of the National Academy of Sciences USA that dogs may be like our human best buds: they get jealous if they feel we're treating another dog better.

Fredericke Range and her colleagues did a series of experiments with dogs that indicated they were happy to "shake hands" whether or not they were rewarded –at least for a while. But that changed if one pup got a treat and the other got nada.

For a long time, scientists believed a sense of equity was a purely human trait. Then in 2003 researchers discovered that capuchin monkeys  complied with requests in return for cucumber slices, but got their backs up when they saw another monkey getting grapes, which they perceived as sweeter, better treats.

You know the famous – some would say infamous -- studies done in the 1950s by University of Wisconsin, Madison, psychologist Harry Harlow in which he separated macaque monkeys from their mothers and put them in cages, where they were then given a choice of bonding with surrogate cloth moms or sucking milk from a baby bottle on a wire?

Turns out the monkeys chose the material mamas every time.  What likely sealed the deal was that Harlow had placed a 100-watt light bulb behind each piece of cloth to warm it.

This study, together with work by John Bowlby on attachment theory, led researchers to conclude that there's a link between physical and emotional warmth.  Having learned  about this in college from Bowlby skeptic Jerome Kagan, I was curious about a paper published today in Science that found the following: a person holding a cup of hot coffee was more likely to view others as warmer than if he or she were holding a glass of iced java. The researchers discovered further that volunteers holding something warm were also more more likely to hand over a $1 gift certificate for ice creamto pals than claim a Snapple voucher  for themselves. And if they were clutching something cold? You guessed it: they were more likely to keep the Snapple for themselves. In other words, researchers concluded, holding something warm makes you feel more generous toward others; holding something cold makes you, well, cold and selfish.

Nearly half of the monkeys, apes and lemurs in the world are in imminent danger of disappearing from the planet, according to a new survey. The news comes even as a separate new census has uncovered far more gorillas than expected.

The International Union for Conservation conducted its first survey of the 634 known primates in five years and found that 48 percent face extinction. Particularly at risk are the great apes like orangutans.

"The situation is far more severe than we imagined," said Russell Mittermeier, president of Conservation International and chairman of the IUCN's primate group, at the release of the analysis in Edinburgh. Although tropical forest destruction remains the main cause, "in many places, primates are quite literally being eaten to extinction."