The economic value of gossip

You don't have to go far to hear someone say something bad about gossip. People even gossip about gossip. One good thing about gossip: it may have had some role in the origin of human speech, as John Tierney reminds us:

Language, according to the anthropologist Robin Dunbar, evolved because gossip is a more efficient version of the "social grooming" essential for animals to live in groups.

Speech enabled humans to bond with lots of people while going about their hunting and gathering. Instead of spending hours untangling hair, they could bond with friendly conversation ("Your hair looks so unmatted today!") or by picking apart someone else's behavior ("Yeah, he was supposed to share the wildebeest, but I heard he kept both haunches").

But Tierney goes on to discuss more recent research on the effects of gossip. In this new study, participants played an economic game using evidence about their trading partners -- and gossip:

In a couple of rounds, each donor was given both hard facts and gossip. He was given a record of how his partner had behaved previously as well as some gossip -- positive gossip in one round, negative in another.

The donor was told that the source of the gossip didn't have any extra information beyond what the donor could already see for himself. Yet the gossip, whether positive or negative, still had a big influence on the donors' decisions, and it didn't even matter if the source of the gossip had a good reputation himself. On average, cooperation increased by about 20 percent if the gossip was good, and fell by 20 percent if the gossip was negative.

Gossip, apparently, is so valuable to us that we rely on it even when it contradicts the hard evidence we have on hand. Could this be a detrimental by-product of the evolutionary origins of language? Or does relying on gossip usually turn out to be a valuable way of getting along? Maybe only in bizarre controlled conditions do we see its potential shortcomings.

But that wouldn't explain gossip's overall negative reputation. Perhaps there's a little cognitive dissonance going on here: If it's about me, it's "gossip," but if it's about you, it's "information."