"there is a mountain of evidence that sex is a huge predictor of all sorts of outcomes, from health to pay to crime, to voting, to religion; anything you can think of....  scientifically speaking the view that sex matters is not remotely controversial. Yet many academics and students of course are too afraid to say it... This isn't just an attempt to stop us from speaking; it's an attempt to stop us from knowing.  Why are gender identity activists so outraged by data collection on sex?...  I think the only answer to that question is that data on sex allows us to state certain facts. And those facts about sex are really inconvenient for gender identity theory." 

Full video. 

Sullivan at Sex Matters and in the TLS