Who can you trust?

Regular readers will know that not so long ago I read and very much enjoyed Steven Pinker’s The Blank Slate, which is about the influence of genes on human psychology. That isn’t my area of expertise, but he seemed to be on the level. His reasoning was mostly reasonable and his evidential claims were backed up by sources which sounded reputable enough. The first half of chapter 18 was about psychological differences between the sexes. He argued that there was strong evidence that some psychological traits are correlated with sex and some evidence that genetic differences between men and women contribute to these correlations. As I say, he seemed to be on the level and know his stuff, so I believed him.

Last week I got some conflicting signals, though. I read Cordelia Fine’s Delusions of Gender, and I enjoyed that a lot too. Fine’s book is about the claims made about psychological differences between men and women, both by scientists and popular writers drawing on the work of scientists. I suppose if I was summarising its claims in bullet points, I’d pick these: 

• There isn’t as much evidence for psychological differences between the sexes as a lot of people make out.
• A lot of the research into this sort of thing is done very badly.
• A lot of the popular writers either misinterpret or wildly extrapolate from what evidence there is, and sometimes just make things up.
• The hypotheses getting tested tend to be based on stereotypes.
• There’s no shortage of places to look for non-genetic explanations for the differences that have been found.

Fine seemed to be on the level just as much as Pinker did, and what she said was largely pretty persuasive. Since she went into far more detail about this specific issue than Pinker did, I suppose my credences are currently balanced in her favour, and my trust in the other 20½ chapters of Pinker’s book is correspondingly undermined. Mostly though, I just don’t know what to think. Fine goes into far more detail about the methods of the research she disagrees with than those of the research she uses to support her positive claims, so I’ve no way of knowing that I won’t read another book in a few months’ time which critiques that just as severely. If she had gone into as much detail about it all it would have doubled the length of her book though, so I can kind of see why she didn’t.

I like reading non-fiction, and I particularly like reading science books pitched at about the level Pinker’s and Fine’s books are pitched at. But I sometimes wonder why I bother. I’m trying to learn but if what I end up believing depends on which persuasive-sounding books are entertainingly written and easy to get hold of, then I’m not learning at all; I’m just making myself an unwitting vehicle for the memes I happen to get infected with. That’s no good. If all I’m going to learn from reading non-fiction is that scientists disagree with each other just as much as philosophers do and nobody really knows anything about anything, then maybe I’ll just read PG Wodehouse all the time.