Aaaactshually… I think that most hetero men are attracted to women that look like they are likely to be fertile. Argument: most mainstream, male-targeting hetero porn features women between 18 and, say, 40 or so. I do not believe that the average hetero man consciously thinks, hey, she looks like she could have my kids when it comes to raw attraction, it is more likely that things that are correlated with fertility (health, age, secondary sexual characteristics) are commonly seen as attractive.