SSS 2010-02-02（在线收听）

When your kids misbehave, maybe you tell them to stop acting like chimps. Well, that would be an insult to the familiar common chimp, Pan troglodytes, which actually grows up pretty fast. Now bonobos, the other chimp species, or Pan paniscus, enjoy horsing around well into adulthood. And a study in the journal Current Biology suggests that their laid-back development keeps bonobos forever young.

The two chimp species are closely related, but when it comes to behavior, there’s little resemblance. While common chimps can be aggressive and incredibly self-serving, bonobos are playful and even prone to sharing, traits that common chimps display mainly when they’re young.

What drives the differences? To find out, scientists observed the apes at all ages. And they found that even as juveniles, common chimps quickly learn to interact preferentially with people they discovered had treats. But bonobos were much more social, approaching experimenters even when they were empty-handed. In fact, adult bonobos rarely reached the levels of psychological sophistication shown by baby common chimps.

So, infinite common chimps on infinite typewriters might churn out Hamlet. Infinite bonobos would more likely produce South Park.