Thursday, January 3, 2008

Bringing TOM to Monkeys

The Smithsonian had a fairly interesting piece, profiling Laurie Santos, a psychologist at Yale, who studies rhesus macaques on the island of Cayo Santiago, just off the coast of Puerto Rico. Santos has created a number of interesting experiments that exploit the monkeys' natural tendency to steal in order to asses whether or not they have a theory of mind--that another agent (in this case us) has thoughts similar to them. It is an incredibly difficult thing to test for in monkeys, but I think Santos is on the right thinking track.

Anyways check out the piece by clicking here.

Trial 1: The experiment relies on one of the most predictable traits of rhesus monkeys: their tendency to steal food at every opportunity. Santos discovered this a few years ago when she and her colleagues were running experiments in cognition and tool use involving lemons, and frequently had to quit early because the animals stole all the fruit. The island's monkeys are supplied with food, of course, and they also forage, but to leave so much as a raisin unguarded is to invite larceny; the researchers eat their own lunches inside a locked cage of cyclone fencing.

The theory-of-mind experiment is designed to test whether the monkeys, who obsessively guard their own food, assume that people do the same. If so, Santos reasons, they should prefer to steal from people who are looking away. So Santos enlists Olivia Scheck and Katharine Jan, Yale student volunteers here for the month. They are dressed alike in blue slacks and white shirts to minimize any confounding effect from their appearance—although there are differences Santos cannot do anything about, because Olivia is several inches shorter than Katharine, and blond, where Katharine is dark-haired. In general, Santos has found, rhesus macaques prefer to steal from the shorter person, although top-ranking dominant males sometimes do the opposite, apparently just to show off.

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