Daniel Finkelstein has been on the Judith Rich Harris again. His latest article quite rightly takes politicians to task for assuming that parenting skills have the slightest effect on the way children turn out. As I've argued many times, they don't.
However, Finkelstein seems to believe that environment must have some effect. He casts around and comes across Rich Harris's thesis. She claims that it is our peer group that forms us. This is almost certainly rubbish too. Peers have no more effect than parents.
The key to the confusion of both Finkelstein and Rich Harris is that they fail to distinguish between innate characteristics and learnt behavior. Some examples of characteristics are intelligence, extroversion, shyness, propensity to addiction, laziness, mathematical ability and optimism. You get the idea and can probably add many more. Behaviour includes language, reading and writing (although how good you are is largely a characteristic) and mathematical knowledge.
Now it is true that you can learn from both parents and peers. It may also be true that you are more likely to learn from your peers than your parents. But Rich Harris is wrong to extend the ability of peers beyond imparting behavior to also shaping our innate characteristics. They can't. Environment (aside from diet) as almost no effect on them at all.
By assuming we can change people by changing their peer group, I fear Finkelstein will send us off on a wild goose chase as pointless as the nurture assumption.
Discuss this post at Science, History and Religion - James Hannam's Forum
Click here to read the first chapter of God's Philosophers: How the Medieval World Laid the Foundations of Modern Science absolutely free.