They don’t really study women. Most sexuality research is focused on men. And “phallometric” studies where they measure boner response in men don’t work well on women, for obvious reasons. We have different genitals and different biological roles, and different protective response than men would.

Most sexuality related research that studies women is survey based so that isn’t particularly helpful either.

I’ve seen studies saying more lesbians have a longer ring finger than index finger than straight women (whose index and ring finger are typically same length). My index fingers are noticeably shorter than my ring finger, and I’ve known other lesbians with the same thing. Gay men’s finger ratios are supposed to be similar to straight women. I haven’t seen that study in a long time and it could be bullshit. Lol. I thought it was funny years ago.

That big “no women are straight” fluidity study actually found homosexuals and heterosexuals to be the most stable orientation and the bisexuals to be “fluid” but of course it was nor reported that way.