Monkeys choose variety for variety's sake
ScienceDaily (2010-03-16) -- Given a choice between spending a token to get their absolute favorite food or spending it to have a choice from a buffet of options, capuchin monkeys will opt for variety. ... > read full article
Oooh, this is a fun one. Some of you ought to remember former East Campus Housemaster candidate and Behavioral Economics professor Dan Areili. He's at Duke now, and appears to be the driving entity of this research.
Its pretty cool from what I see, though I haven't read the paper yet (oh African internet). Chosen variety is closely related to neophilia, a characteristic which appears to divide primates. Even among chacma baboons, there are some which appear to be curious, friendly, and neophilic, and those which are neophobic, who would prefer the same boring stuff again and again, rather than experimenting with variety.
Neophilia appears to be a characteristic of more cognitively advanced primates; despite the fact that capuchins are new world monkeys, they are remarkably intelligent. Unfortunately, as a distant relation, they don't provide a great deal of anthropological info. Behavior is still great, but behavior plus human relations is the where the proverbial money lies.
Anyway, there are very very good reasons for animals to fear new stuff and variation, most of them having to do with the fact that new stuff tends to kill you. So, when you find an animal that isn't afraid of the unknown (within reason, of course), that's exciting business.