Worth getting the ritual genuflection out of the way at the beginning here. You’ll not believe the green inked emails you get if you don’t. Yes, of course there’s something akin to a spectrum over sexuality and gender. Humans are complex beings and the reproduction of one bit can be a tad hazy at times. Leaving aside the correct technical and statistical terms – on the basis that I don’t know them – this is not though a, say, normal distribution, nor one where we’re equally distributed along said spectrum. Anywhere between 90% and 99.9% of the population are clustered in one of two groups, male and female.
In that other grouping there’re all sorts of interesting variations. Human mosaics do exist, where what appears to be the one body has different genetic make up dependent upon which part of the body we’re talking about. Not quite but think of it as the arm being this set of chromosomes, the leg some other. Again, not accurate but as a mental image conjoined twins who are really, really, conjoined. We’ve also those concepts of male and female brain, the work of Simon Baron Cohen showing us that they don’t necessarily – only probably – end up inhabiting a male or female physique. Then androgen insensitivity and so on – a right patchwork of possibilities.
All most fun and all most interesting. And yet we’ve this as well:
Having a male twin is bad for girls, damaging not only their education and job prospects but their chances of a happy family life, new research has found. A 30-year study found girls who share a womb with a male twin go on to perform significantly less well academically and socially than girls whose twin is a girl. The scientists behind the research believe exposure to testosterone in the womb is to blame. They examined data on 13,800 twin births between 1967 and 1978 in Norway, following up the participants for thirty years after birth.
The figures showed that women who had a twin brother were 15.2 per cent less likely to complete high school and 3.9 per cent less likely to graduate from University. They were also 11.7 per cent less likely to get married and showed a 5.8 per cent lower fertility. Meanwhile their earnings were on average 8.6 per cent lower. The scientists at Northwestern believe the differences are explained by biological factors in the womb rather than the social impact of growing up with a male twin because they repeated their analysis on female twins whose brother had died shortly after birth. “This is a story about the biology of sex differences,” said co-author David Figlio, Dean of Northwestern’s School of Education and Social Policy.
Male and female twins will of course be genetically different, almost certainly in separate amniotic sacks as well.
Note what is being said there. These hormonal washes, they’re part of the biology of sex differences. Which is correct, they are:
That’s something I think many cisgender people don’t realise, or think about. We’re all born with the same template, and our hormones then decide what particular bits of the recipe our bodies should follow – so for example in the womb a rush of hormones tells us whether we should grow male or female gonads; in puberty hormones tell us whether to grow breasts or beards. But the template for both sexes remains, so if you take somebody born male, suppress their testosterone and increase their estrogen then their body (and their emotions; jeez, the emotions…) will change. Reproductive systems aside, men and women aren’t that different: the idea that there are huge biological differences between the sexes is largely based on status preservation.
No, it’s not status preservation, those hormonal washes are part of the biology of sex differences.
We around here have absolutely no problem at all with agreeing to be polite about whatever anyone decides they are. But if we’re to go off talking about the science of something then let’s talk actual science, shall we?