Back in 2005 my daughter Charlotte, then a four-year-old, took part in a study to see how kids stack up mentally against chimpanzees. I wrote about the ambivalent experience of watching her as both a father and a curious science writer in the New York Times. The emerging lesson of the study, led by Yale grad student Derek Lyons, was that children overimitate even though they should know better. Lyons showed the children how to get a toy out of a container, adding in lots of unnecessary tapping of walls and sliding of rods and such. Other scientists had tested chimpanzees on similar contraptions and found that they pay more attention to the basic mechanics of the task at hand. As a result, the chimps generally leave kids in the dust (Charlotte included).
Two years later, Charlotte is far too sophisticated for such child’s play. And Lyons is finally publishing the results of his study (with co-authors Andrew Young and Frank Keil) in the Proceedings of the National Academy of Sciences. The paper–along with short videos of some of the kids in action (not including Charlotte)–are all available for free through the joy of open access.
One reason that the project took so long was that Lyons has spent a long time making sure the patterns hold up. He observed about 100 kids, and put them through a wide range of tests. He also addressed a lot of alternative explanations for his results–many of which were raised by astute readers of this blog. For example, he found that the evidence did not support the idea that the kids overimitated simply to please him and his colleagues. He also let some of the kids figure out on their own how to get the toy out without showing them any extra useless steps, and they could quickly solve the problem. (Charlotte created a particularly dramatic data point by ripping the wall off of one of Lyons’s boxes.) Skeptics can judge for themselves from the paper if Lyons has successfully made his case.
It’s funny that this paper comes out the same week as Japanese researchers report that young chimpanzees do an awesome job of memorizing numbers–far better than humans, in fact. In both cases, it’s shocking to think that any other species could do better on the sorts of tasks that seem to tap into what makes us uniquely human, such as math or solving puzzles. But there’s no reason to think of ourselves as simply the top of some great chain of being, superior in all ways to the rest of life. We have evolved to adapt to a particular niche, and the strategies we’ve evolved to solve problems in that niche are not perfect. Closely imitating others is a wise thing to do in a social species like our own, but it’s not hard to get kids to overimitate as a result.
Incidentally, if you want to find out more about this experiment, be sure to check out Lyons’s impressive new web site, Hello Felix.
Originally published December 4, 2007. Copyright 2007 Carl Zimmer.