In the nineteenth century, scientists were very interested in the differences between men and women. Not because they wanted to know more, but because they wanted to justify oppressing women. So they came up with ever more inventive ways to define who was superior and who was inferior.

As historian Susan Sleeth Mosedale writes in Science Corrupted: Victorian Biologists Consider “The Woman Question”, scientists wanted to attack feminism. As reported by Jstor Daily:

These attacks were often riddled with contradictory evidence and conflicting analysis, Mosedale argues. The scientists “operated in blissful ignorance of their prejudices,” allowing their own “socially conditioned feelings” to guide their application of scientific theories. Biologists grasped for vaguely scientific reasons why women shouldn’t be allowed to vote, get an education, or aspire to anything more than having babies.

So the scientists created an “index of inferiority” to decide who got rights and who didn’t.

One biologist argued, for example, that women “exhale less carbonic acid,” proving them to be mentally and physically “more sluggish” than males. This supported the antifeminist argument that “the sum total of food converted into thought by women can never equal the sum total of food converted into thought by men. It follows, therefore, that men will always think more than women.” Another apparent “mark of female inferiority,” writes Mosedale, was “the relatively low proportion of carbonate of lime in feminine bones: 4.52 parts, compared with 9.98 parts for the male.”

This is, of course, confirmation bias: the scientists set out to prove that women were inferior to men and less deserving of human rights, and they desperately searched for anything they could point to in order to protect their own privileged status. They did similar things with race, and with disability: the horrific history of eugenics was based on pseudoscience.

You don’t need me to point out the parallels with today’s attempts by anti-trans activists, people who use confirmation bias to justify abuse of and discrimination against trans women: their focus on biology and science is only on the biology and science they can weaponise in order to exclude others, not the overwhelming evidence that they are wrong. It’s just saddening to see the same thing happening again and again throughout history.

In 1890, the philosopher David G Ritchie noted that “scientific” discrimination was:

always the favourite sort of argument with the jealous champions of privilege: first to prevent a race or class or sex from acquiring a capacity, and then to justify the refusal of rights on the grounds of this absence—to shut up a bird in a narrow cage and then pretend to argue with it that it is incapable of flying.