>I think the whole youth and beauty thing falls out of this.
Yes, you're right but that is more of a side-effect of why we value youth and beauty: our primary drive for sex is to reproduce, and there is a nice bell-curve on the age of a person as to when that is optimal, made clearly obvious by their outward appearance of youth and beauty.
Plenty of older people have sex, and I've heard anecdotally that retirement homes are a good place for finding a partner.
Yes, you're right but that is more of a side-effect of why we value youth and beauty: our primary drive for sex is to reproduce, and there is a nice bell-curve on the age of a person as to when that is optimal, made clearly obvious by their outward appearance of youth and beauty.
Plenty of older people have sex, and I've heard anecdotally that retirement homes are a good place for finding a partner.