Being attracted to someone *relatively younger* has an easily observed reproductive advantage - 25 year olds are more likely to succesfully bear healthy offspring than 35 year olds. Much the way that washing your hands has an advantage because you're more likely to live longer and have more children. That obviously goes off the rails if taken to an extreme. If you wash your hands 45 times a day you'll scrub your skin off and get an infection. If you molest 9 year olds you'll get capped by your neighbors or declared the "prophet" of a pedo religion. Sexual behavior is also *massively* a learned behavior. If your mom married a drunk, you're likely to immitate that behavior. If you got bad-touched by a pedo, you're also highly likely to immitate that behavior either directly (pedos reproduce by molesting kids), or indirectly through homosexuality. Homosexuality is largely driven by pedos. E.g. lesbians were molested as children at 23x the baseline rate.