Take first Dave Osler’s contrast between Jade Goody and my fellow Corpuscle Gail Trimble. He says that “basic family details alone would be sufficient for most of us to have no difficulty in predicting” their very different academic attainments. But his first commenter points out that many people from poor backgrounds are academic achievers.
The commenter misses the point. Dave is claiming a correlation between background and academic achievement. Pointing to one or two instances where the link doesn’t hold does not refute Dave’s claim. It merely shows that the correlation is less than 1.0 - but no-one is claiming that it is.
What neither side does, however, is refer to empirical evidence. But this exists. For example, this recent paper seems to support Dave’s point. It shows that there is a positive correlation between parents’ and childrens’ reading and maths abilities even at age 7. Bright parents have bright children. But the correlation, whilst positive and significant, is sufficiently far from one for there to be many bright children from less bright parents*.
My second example is this rather vitriolic dispute about home schooling between David Semple and Bishop Hill.
But surely, the question about the merits or not of home schooling is largely (not entirely) an empirical one; do home-educated people do better than school-educated ones? Neither David nor Bishop provide evidence (Bish’s link is broken) - not even a link to this fine blog. But there is some. This US research shows that test scores of the home schooled are “exceptionally high”. Of course, this might be because they come from the sort of families that would ensure they did well even if they went to school. Or it could be that this achievement comes at the expense of other things - for example, worse “soft skills” as a result of not mixing so much with others.
But these are empirical matters, which require research. So why the abuse?
I say all this not to condemn the individuals concerned, but rather to draw a contrast between two approaches to political issues.
One approach assumes that the resources of one’s own ego - prejudice and anecdote - are sufficient to settle a question. You know that home schooling is good (or bad), that there are no barriers to social mobility, that single parents are scroungers, that Israel (or Hamas) is right. And so on. So you just abuse the other side and wallow in your self-righteousness.
The other approach, though, is to ask: what exactly is the evidence? What would count as good evidence?
This latter approach, though, is a minority one. I suspect that we live not in an age of science and empiricism, but rather in an age of ego.
* The data doesn’t wholly vindicate Dave, though. He claims that “human beings are born with more or less equal potential.” But there seems to be a big genetic component in maths ability.