Today a friend told me a story she heard about a study that was done among chimpanzees in Africa. I suspect the story is apocryphal, but in a way that makes it even better.
It seems that some scientists had been studying a group of chimpanzees, and had observed behavior which in humans correlates to depression, such as eating at odd times, spending lots of time alone, and staying on the outskirts of the group. This behavior was observed in about 10% of the chimps, which happens to be near to the percentage of Americans who show symptoms of depression.
The scientists removed the depressed chimps for six months, to see how this would affect the behavior of the other 90%. It’s possible that the chimps signed a voluntary consent form for participating in such a disruptive study, but I’m not holding out much hope.
You might think that in the absence of the depressed individuals, the remaining majority would produce another 10% of depressed chimps. But apparently that’s not what actually happened.
What actually happened was this: When the scientists returned six months later, all of the non-depressed chimps were dead.
It would seem that the depressed chimps had functioned as a kind of early warning system, continually looking out for predators, tropical storms, and other threats to the group. Without that system in place, the group was doomed.
When I heard about this study, I remember thinking how great it would be for depressed people. Instead of being a problem to be fixed, they would know that their condition is a valuable asset to society, providing a critical mass of individuals uniquely suited to guarding against danger.
I figured this would make my depressed friends vey happy.
Oh no, I thought. What happens if we become a society with no depressed people? We are all doomed.