For a Chimp, Risky Business is Good Business

March 27, 2008 -- It's late at night, you are in a town you don't know well, and all the restaurants are closing.

Famished, you spot a stall that will sell you a small snack.

Should you take the snack or venture further, hoping to find a place that will serve you a hearty meal but knowing that you may also find nothing?

Most of us would go for the safe option -- we prefer to have at least a little to eat rather than take the risk of going hungry if the quest for a bigger reward goes awry.

Scientists have carried out an innovative experiment among our closest relatives, chimpanzees and bonobos, in an attempt to explain why this is so.

In a paper appearing on Wednesday in Biology Letters, published by Britain's Royal Society, U.S. and German animal behaviorists recruited five chimps and five bonobos at a primate research centre at Leipzig Zoo, eastern Germany.

The apes had to choose between two upside-down bowls.

One was the "safe" bowl, which always covered four grape halves.

The other was the "risky" bowl, which covered anything between one and seven grape halves.

Chimpanzees turned out to be big risk-takers, invariably tempted to go for the grand prize even if this also meant frequent disappointment.

Bonobos, like humans, were strongly risk-adverse, and preferred to go for the fixed, dependable reward.

The chimps' love of risk is in keeping with previous findings. Compared with bonobos, chimpanzees are more patient, waiting longer to get their hands on a delayed treat.