Underage sex
Since the age of consent is often higher than the upper age limit in the definition of clinical pedophilia, underage sex, i.e. sexual activity with underage adolescents, is not, in general, clinical pedophilia. While such activity may be illegal in a particular jurisdiction, it frequently exemplifies only borderline pedophilia, or far more commonly, no pedophilia at all, because the person's attraction is not specifically to persons that young. The terms hebephilia and ephebophilia are sometimes used to describe attraction to youths or adolescents, distinct from attraction to children.
Most cases of father-daughter incest are believed to involve fathers who are situational offenders, rather than clinical pedophiles.
Some have argued that these cases are caused by the withdrawal of the mother (often due to mental illness) from the family -- this withdrawal is more than purely sexual.
Modern cultures in general strongly condemn underage sex and regard it as a very serious crime, based on the idea that children are not sufficiently mature to be able to consent to sex and that sex with children is therefore rape.
Pederasty is underage sex, especially anal sex, between male adults and male adolescents or children. The North American Man-Boy Love Association advocates legalization of pederasty.
See also: