Schneier on Security
A blog covering security and security technology.
April 17, 2008
Risk Preferences in Chimpanzees and Bonobos
I've already written about prospect theory, which explains how people approach risk. People tend to be risk averse when it comes to gains, and risk seeking when it comes to losses:
Evolutionarily, presumably it is a better survival strategy to -- all other things being equal, of course -- accept small gains rather than risking them for larger ones, and risk larger losses rather than accepting smaller losses. Lions chase young or wounded wildebeest because the investment needed to kill them is lower. Mature and healthy prey would probably be more nutritious, but there's a risk of missing lunch entirely if it gets away. And a small meal will tide the lion over until another day. Getting through today is more important than the possibility of having food tomorrow.
This behavior has been demonstrated in animals as well: "species of insects, birds and mammals range from risk neutral to risk averse when making decisions about amounts of food, but are risk seeking towards delays in receiving food."
A recent study examines the relative risk preferences in two closely related species: chimanzees and bonobos.
The basic argument is that in the natural environment of the chimpanzee, if you don't take risks you don't get any of the high-value rewards (e.g., monkey meat). Bonobos "rely more heavily than chimpanzees on terrestrial herbaceous vegetation, a more temporally and spatially consistent food source." So chimpanzees are less likely to avoid taking risks.
Fascinating stuff, but there are at least two problems with this study. The first one, the researchers explain in their paper. The animals studied -- five of each species -- were from the Wolfgang Koehler Primate Research Center at the Leipzig Zoo, and the experimenters were unable to rule out differences in the "experiences, cultures and conditions of the two specific groups tested here."
The second problem is more general: we know very little about the life of bonobos in the wild. There's a lot of popular stereotypes about bonobos, but they're sloppy at best.
Even so, I like seeing this kind of research. It's fascinating.
EDITED TO ADD (5/13): Response to that last link.
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