The nativism-empiricism debate haunts the fields of language acquisition and evolution on more than just one level. How much of children’s social and cognitive abilities have to be present at birth, what is acquired through experience, and therefore malleable? Classically, this debate resolves around the poverty of stimulus. How much does a child have to take for granted in her environment, how much can she learn from the input?
Research into imitation has its own version of the poverty of stimulus, the correspondence problem. The correspondence problem can be summed up as follows: when you are imitating someone, you need to know which parts of your body map onto the body of the person you’re trying to imitate. If they wiggle their finger, you can establish correspondence by noticing that your hand looks similar to theirs, and that you can do the same movement with it, too. But this is much trickier with parts of your body that are out of your sight. If you want to imitate someone sticking their tongue out, you first have to realise that you have a tongue, too, and how you can move it in such a way that it matches your partner’s movements.
In my last post I wrote about two experiments on imitation in young children and chimpanzees by Lyons et al. (2005) and Horner & Whiten (2005). Their results suggested that young children tend to copy both the ‘necessary’ and the ‘unnecessary’ parts of a demonstrator’s action who shows them how to get a reward out of a puzzle box, whereas chimps only copy the ones necessary to get the reward.
One important question raised by these experiments was whether these results can only be applied to wild chimpanzees or whether they also hold for enculturated, human-raised chimps. This is an important question because it is possible that chimpanzees raised in these kinds of richly interactive contexts show more sensitivity to human intentionality.
Buttelman et al. (2007) tested just that. They used the “rational imitation” paradigm, which features two conditions
a) the subjects are shown an action in which the specific manner of the action is not purposive and intentional but results from the demonstrator being occupied with something else. For example, he may be carrying something so that he has to use his foot to turn on a light (often called the Hands Occupied Condition).
b) the subjects are shown an action in which the demonstrator chooses a specific manner of doing something on purpose. For example he may have his hands free but still choosto turn on the light with his foot (Hands Free Condition).
Imitation is often seen as one of the crucial foundations of culture because it is the basis of social learning and social transmission. Only by imitating others and learning from them did human culture become cumulative, allowing humans to build and improve on the knowledge of previous generations. Thus, it may be one of the key cognitive specializations that sparked the success of the human evolutionary story:
Much of the success of our species rests on our ability to learn from others’ actions. From the simplest preverbal communication to the most complex adult expertise, a remarkable proportion of our abilities are learned by imitating those around us. Imitation is a critical part of what makes us cognitively human and generally constitutes a significant advantage over our primate relatives (Lyons et al. 2007: 19751).
Indeed, there have been some interesting experiments suggesting that the human capacity -and, above all, motivation – for imitation is an important characteristic that separates us from the other great apes.
In a series of intriguing experiments by Victoria Horner and Andrew Whiten from the University of St. Andrews in Scotland, and Derek Lyonsand his colleagues from Yale University, young wild-born chimpanzeesand Children aged 3 to 4 were shown how to get a little toy turtle/ a reward out of a puzzle box. In the first condition of the experiment the puzzle box was transparent, whereas in the second condition the puzzle box was opaque.
And here’s the catch: both chimpanzees and children were not shown the ‘right’ or ‘simple’ solution to how to get the reward but one that was actually more complicated and involved unnecessary steps.
I always remember 2008 as the year when the entire UK media descended upon the former mining town of Bridgend. The reason: over the course of two years, 24 young people, most of whom were between the ages of 13 and 17, decided to commit suicide. At the time I was working in Bridgend, so I’m able to appreciate the claims of local MP, Madeleine Moon, that media influence had become part of problem. After all, most editors will tell you: the aim is to sell newspapers. And when this rule is rigorously applied, it should not come as a surprise at the depths some journalists will sink to recycle a news story. Even at a local-level, where you’d think some civic responsibility might exist, journalists clambered over themselves to find a new angle, generating ridiculous claims such as: electromagnetic waves from mobile phones caused the suicides.
Earlier this year I went along to the Cultaptation Conference at St Andrews. Despite being a fascinating event, there appears to nothing on the blogsphere pertaining to the speakers and their talks. In fact, this generally holds true for cultural evolution: there are no dedicated blogs reporting what is undoubtedly a serious scientific endeavour. As a remedy I’m going to dedicate several future blog posts to the conference. Until then, here are the talk abstracts for some of my personal highlights: