these chimps are no chumps: part II

In Part One (which wasn't supposed to start a series, but why not?), I pointed to a report of isolated colonies of chimps that developed similar tool-using skills. Biologists were sure a river between the groups prevented "cultural transmission." Perhaps--but what if one chimp forded the stream? It might be possible, because it turns out that chimps are much better at teaching and learning than we thought.

The team trained one chimp to lift the flap to get a food reward, then let a second chimp watch the first one demonstrate the technique several times. The "teacher" was then removed and a new naïve apprentice was brought in to watch the newly taught chimp, and so on.

A second cultural lineage was started with a chimp trained to slide the door instead of lifting.

In both lineages, the knowledge was passed down almost perfectly: through six teacher-pupil iterations, chimps trained by lifters always lifted, and through five generations sliders always slid.

The researchers observed only a single error, a slider that lifted once out of 20 trials; its apprentice learned to slide anyway.

The result shows that cultural learning is strong in chimps, says Horner. "If the chimps weren't learning from each other, we'd expect over a couple of generations it would degrade to a 50-50 performance. If they weren't very good at copying, you wouldn't see this almost 100% accuracy."

Will this lead to a ban on chimps smoking on television and the silver screen?