On Beliefs in Science

When I was an Honours student, as part of our ‘Science Communication’ module, we had several scientists from our university come and talk about their research. During the Q&A, someone brought up the topic of women and science (and why there are so few of them). The conversation continued outside the venue, where we were arguing with a (male) lecturer about women’s cognitive abilities (and supposedly hence their suitability for science). At one point this lecturer told us that we were not like typical girls (whatever that means), probably in an attempt to explain why we were there and others of our gender were not. We were trying to explain that women are socialised with different expectations, which could explain why there are so few of us in the profession. Deaf to our pleas, the lecturer promptly mentioned the recent, at the time, PNAS article which supposedly showed differences in then wiring of male and female brains. He meant this study to be his coup de grâce for the conversation, but I had already read Cordelia Fine’s take on such exasperating neurosexism (coined by Fine), which is that the study did not consider the fact that female brains (which are smaller on average than male ones) are not male brains scaled down. In her own words (emphasis mine):

“One important possibility the authors don’t consider is that their results have more to do with brain size than brain sex. Male brains are, on average, larger than females and a large brain is not simply a smaller brain scaled up.”

When I mentioned this criticism to said lecturer, he promptly went on to explain how he and his wife were different and for those of you who have been reading this blog would know that anecdotes are not evidence.

I mention this story because I recently came across this blog post (see here) on Fine’s new book, Testosterone Rex: Myths of Sex, Science, and Society. I have read her previous book, Delusions of Gender, which I found to be a breath of fresh air when it comes to discussing sex differences. In short, her main point is that because boys and girls are socialised differently based on gender, any study which wants to look at biological sex differences in cognition will be tainted with this effect. Scientists, like all fallible humans, have certain beliefs about the world which cloud our view of the evidence; when we come with the expectation that there will be biological sex differences in how our brains work, any supposed differences found will be attributed to biology (rather than upbringing). But, as scientists, we are supposed to go one step further than most people, and actually critically assess our initial assumptions, or else someone will do it for us.

Now, since I have not read her second book I will make no comments specifically on the book itself. I do not think that she holds an ideological belief that there are no innate biological sex differences in cognition between males and females, as mentioned in the blog post I read. Her main message in Delusions of Gender is that testing for such differences is inherently hard and we need to have robust evidence to make such claims. For example, say a study looks at three month old babies and manages to find a difference between the eye contact to faces made by male babies as compared to female babies. The researchers chirpily conclude that since female babies look at faces for longer, they are more primed for emphasizing than males. But is such a conclusion correct? First, you would have to examine whether their results were not some statistical fluke, that they had a large enough sample size (which is rarely the case in human centered research) to be able to statistically detect such a difference. Secondly, even if there is a real statistical difference in eye contact times, this does not automatically translate into a biological difference. Lastly, the researchers would be assuming that three months is young enough for socialisation to not have an effect. But who knows on that point? Maybe younger than three months is the critical period for the socialisation of babies? So even if the study passed the first two hurdles, the interpretation of the results still rests on this critical assumption. That is not to mention how eye contact time would translate into differing abilities to emphasize, and it could be that eye contact has no bearing whatsoever on this ability.

I do not mention this to say that science has no value or that we all may as well be tarot card readers when it comes to our conclusions. Only that science is very, very, very difficult to do. It is when our assumptions are left unquestioned that they turn into beliefs. And science is not in the business of believing, but in a critical appraisal of the evidence. So the next time you see a headline with a snappy conclusion, you have to think, what are their assumptions and does this hold up to scrutiny?

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