I don't know whether the Madonna-Whore complex is universal, and I bet you don't either.

Hence, "a lot of," "appear to," and "something like."

The relevant thing for Sally and Bob is that they've grown up in a culture which is influenced by the Madonna-Whore complex, and there's some risk that it will affect the outcomes of their choices.

I'm not sure how valuable it is to talk about culture instead of memes and genes. There are a lot of specific elements we can talk about, and none of them are universal. Saying that the "culture" disapproves of pre-martial sex is as accurate as saying the "culture" approves of pre-marital sex, and since both X and !X are true, X might not be a good way to look at the situation. We could instead talk about the memes approving and disapproving of premarital sex (for men and women respectively), as well as the meme that men and women should be treated equally.

For example, I found this comment fascinating, because it highlights this interplay of emotions and memes. The meme of "don't make sexual orientation a deciding factor" made him decide to block a neutral-win-win encounter because that would open up the possibility of a lose-win-win encounter, suggesting that in this case the meme's effect was not benign. (I suspect that overall the meme is a beneficial one, but that doesn't mean it doesn't have negative side effects.)