I'd bet that a substantial portion of humans are naturally bi and shaped by their environment but there are some humans that really are Kinsey 0s or 6s. We're just rarer. I'd also guess the reputation that conversion therapy has for not working is because anybody in such a hostile environment with even a smidge of opposite-sex attraction is going to act 'straight' and the only people sent off to the conversion camps are the people for whom it wouldn't work.
> People who are straight occasionally do become bi or gay, and vice versa.
Past puberty? Do they really change sexual orientation or do they realize they were X all along? And is it really the result of acclimatization or the result something else, like a biological process? I admit I didn't know that was a thing. Also, a problem is that most of this research is based on self-reporting, which is notoriously unreliable. Ideally researchers would find ways to measure sexual arousal directly, but I guess it would be more difficult to find participants and setup experiments.
Adult pedophiles can stop being sexually aroused by children, because there's still a cognitive component to it. In the same way that you might for example, stop being attracted to your partner if you start associating them with a negative memory, a softcore pedophile might lose their attraction to children if they begin to associate it with a negative emotional response from the child.
>Past puberty? Do they really change sexual orientation or do they realize they were X all along?
They quite literally change sexual orientation. The same way you might stop liking sugary foods if you go off them for a while, or how you might develop a taste for leafy greens if you give them a go enough times.
As far as general sexuality, the keyword you can look for is 'sexual fluidity', and as far as pedophiles are concerned, Mashall's "Are pedophiles treatable?" covers current approaches that seem to be successful in attenuating or replacing attraction to children.
>Aversion conditioning is understood to change behavior more than desire
Behavior and desire have a complex relationship, it's not necessarily the case that behavior follows from desire.
>And many people do not develop a taste for leafy greens or heterosexuality after decades.
Many people don't, but some do, and my comment concerns the 'some', hence my saying 'occasionally'.