That's probably due to the irrelevance of the TINY minority of trans-folk who manage to slip past psychiatric screenings and get gender-reassignment surgery due to 'psychological issues'. This is an article about biological sex and it's mostly misunderstood complex nature. NOT an article on *gender identity*, or an article on the rare cases of mental illness DISPLAYING as gender-dysphoria (or CO-MORBID in an individual with a gender-identity which doesn't match their biological sex, but who has zero dysphoria). But your comment is fairly telling about your ignorance and misinformation on the topic of gender identity (which, btw, is NOT a psychological issue, NOR a BIOLOGICAL issue - it's a personal choice, given that it's not some inherent trait, it's a societal construct which has outlived its usefulness in light of current advances in understanding the complexity of biological sex, as well as our social advances in learning what is none of our goddamn business (clearly still a WIP)