spite makes the man

Score one for human exceptionalism:

Spite is a common human reaction, says Jensen. "Imagine you're a kid at a birthday party. The mother gives you cake, then takes it away and gives it to another kid. It's not his fault, but you'll still be annoyed with him because of his good fortune. But chimps don't care who's got the cake, just who took it from them," he explains. In other words, chimps fail to see things from another's point of view.

And if a chimp's lack of empathy leaves it unable to feel spite, it may also fail to behave altruistically, says behavioural ecologist Rufus Johnstone of the University of Cambridge in the UK. "There have been experiments that gave chimps the chance to be nice to another at no cost to themselves, but they weren't interested. They didn't have a human propensity to be nice," he says.

"This is where things get tricky," admits Jensen. "Other papers coming out of our research group show chimps are altruistic. One interpretation is that one set of researchers isn't doing their job properly, but we don't like that one! Maybe altruistic tendencies operate in a narrow range in chimps, and a broader range in humans."

Well, maybe score .75. We haven't exactly tested for spite in dolphins. At least, as far as I know.