Bartering among chimpanzees

Somewhat related to my last post, PLoS One also has an interesting article, this one about bartering among chimpanzees.

Chimpanzee Autarky by Sarah F. Brosnan et al.

Background

Economists believe that barter is the ultimate cause of social wealth—and even much of our human culture—yet little is known about the evolution and development of such behavior. It is useful to examine the circumstances under which other species will or will not barter to more fully understand the phenomenon. Chimpanzees (Pan troglodytes) are an interesting test case as they are an intelligent species, closely related to humans, and known to participate in reciprocal interactions and token economies with humans, yet they have not spontaneously developed costly barter.

Methodology/Principle Findings

Although chimpanzees do engage in noncostly barter, in which otherwise value-less tokens are exchanged for food, this lack of risk is not typical of human barter. Thus, we systematically examined barter in chimpanzees to ascertain under what circumstances chimpanzees will engage in costly barter of commodities, that is, trading food items for other food items with a human experimenter. We found that chimpanzees do barter, relinquishing lower value items to obtain higher value items (and not the reverse). However, they do not trade in all beneficial situations, maintaining possession of less preferred items when the relative gains they stand to make are small.

Conclusions/Significance

Two potential explanations for this puzzling behavior are that chimpanzees lack ownership norms, and thus have limited opportunity to benefit from the gains of trade, and that chimpanzees' risk of defection is sufficiently high that large gains must be imminent to justify the risk. Understanding the conditions that support barter in chimpanzees may increase understanding of situations in which humans, too, do not maximize their gains.

I was under the impression that chimpanzees traded somewhat similar to humans (though without the use of money), but obviously this not the case. From what I got out of the article, the chimpanzees didn't quite seem to grasp the concept of money when introduced to it, and often traded in non-beneficial ways because of this. While this is not too surprising, given that they don't use money themselves, observation of other forms of bartering showed similar behavior.