Rat Reciprocity

What is it that makes us uniquely human? Is it our intelligence, no, dolphins and monkeys are plenty smart. Is it our capacity for self-awareness? Nope, apes, dolphins and elephants have been shown to be self-aware. Mourning the dead? Nope, elephants do that. In fact we could go through a pretty long list of traits that we might think are uniquely human, only to find one or more animal species that also show this trait. So its a relief to find a study published this week that allows us to hold on to the one trait that, so far at least, remains uniquely human - spite. (Incidentally there are very few scientific experiments I'd want to watch on video but I'd make an exception for this one. Chimps and collapsing tables of food sound like a great combination).

Also, just published, the first evidence of an unusual form of altruism, termed 'generalized reciprocity': Generalized Reciprocity in Rats. In the first example of general cooperation in any animal, rodents helped by unfamiliar rats are found to help strangers themselves.

This time last year: Running after Antelope