by far the most interesting part of the latest You’re Wrong About on homosexuality in the animal kingdom is the account of how science missed it for so long. the guest, lulu miller (of radiolab fame) basically divides the reasons into three categories: ignorance, self-suppression, and what you might call “official” suppression.
essentially, since the days of thomas aquinas when it had been simply declared that homosexuality was inherently against nature, you had a lot of observers of the natural world, even once the enlightenment got underway, who simply didn’t know what they were looking at. many animal species are very sexually dimorphic and thus easy to sex; but many more are not, and if your background assumption (because the background assumption of society in general) is that homosexuality does not occur in nature, if you see two animals of unidentified sex mating, you will assume one is male and one is female. or you might simply assume what you are seeing is an aberration, with no real systemic significance, and not pointing to any kind of underlying phenomenon, and simply fail to note it down–or talk to any other naturalists about it.
and this blends into self-suppression, which includes all researchers who might have noticed homosexuality among animals in the wild, but didn’t write about it. this includes researchers who might not have thought it was significant, or who might have thought nobody was interested in it–miller offers the example of a guy who died relatively recently who spent his life studying mountain rams, who omitted mentioning from his quite detailed survey of their behavior that about one in twelve males mate exclusively with other males, because it seemed to him (at the time of writing) an aberrant and unpleasant fact about an otherwise majestic creature.
“official” suppression we might apply to any time a researcher noticed and wanted to write about the phenomenon, but who simply couldn’t get their data published, including researchers who might have pressed the scientific community at large to recognize this phenomenon, only to be greeted with hostility and suspicion–i.e., what kind of pervert is so obsessed with this topic?
and out of a combination of all these factors you get centuries of a bias being confirmed, because anybody who might care to ask, “well, homosexuality clearly occurs in humans, have we observed it in other animals?” would have been confronted with a vast lacuna in the scientific literature, not because it did not occur, but because multiple intersecting cultural biases prevented anybody from actually talking about it. and it makes it hard to have a conversation about natural phenomena from an empirical and rational perspective when a bias that irrational runs that deep! and i cannot help but wonder what other biases we have in our culture, that might be producing similarly irrational lacunae in our apprehension of the world.