Gender Studies - Why do majority of men think that women over 40?

In the words of the late Notorious B.I.G., play YOUR position. If you're 40 you really shouldn't be worrying about what guys in their 20's are thinking or saying. They are not for you. No matter how good a shape you are in. Your group of men are generally within a few years of your own age group. If you solicit their advise you'll find that most think that 40+ women are highly attractive and that the beautiful beach bunny sort is great to look at, but not great to own.