You claim that only the sex of the other person involved is relevant, and not whether the intercourse is with someone of the same or opposite sex. This is wron

You claim that only the sex of the other person involved is relevant, and not whether the intercourse is with someone of the same or opposite sex. This is wrong, and shows precisely the lack of understanding of conditional probability that I described. I am especially shocked by your use of lesbian intercourse as an example, since everyone knows the issue is men-who-have-sex-with-men. Lesbians are completely irrelevant to this debate. Let us compare the probability of a man getting AIDS from having sex with a random man, vs a random woman. As you say, these are probably similar. However, it might be very hard for a man to convince another random man to have sex with him! So what we really want to calculate is the probability of getting AIDS from a random, actually occurring, sexual encounter (not with a prostitute) between a man and a woman, and a man and another man. This is what the statistic is intended to mean, and how people will interpret it, even if it is not always properly qualified. In this case, the probability of the man who has sex with a man getting AIDS is much higher, because gay men have a much higher incidence of AIDS than heterosexual women. So we could add the following useless disclaimer to my earlier claim: if you are a man, sex with a randomly chosen man (including straight men) is not especially dangerous. It's only when you condition on that man being gay that it becomes statistically more dangerous. Of course, this disclaimer would still be wrong since the sex with the man would probably be anal, which is inherently more likely to spread AIDS. >What's more, the qualifier that it has to be with a white woman is important. That's why I included it :) I can't comment on why AIDS is higher for heterosexuals in Africa than the US. I don't necessarily accept your claims about it. But that is not the issue here. I am talking about the probability of getting AIDS given the current situation, not any inherent link between being gay and AIDS. The actual cause is not relevant. The best that you could say, is that the reason for these misleading statistics is not to promote gay rights, but to scare people into taking precautions that are good for society as a whole.