"Термин "инбридинг" применяется только по отношению к животным."
Definition
inbred (RELATED) [Show phonetics]
adjective
produced by breeding between closely related plants, animals or people:
an inbred population/family/strain
inbreeding [Show phonetics]
noun [U]
when plants, animals or people are inbred:
the dangers/effects of inbreeding
(from Cambridge Advanced Learner's Dictionary)
Definition
incest [Show phonetics]
noun
sexual activity involving people who are closely related and not legally permitted to marry:
a victim of incest
http://dictionary.cambridge.org/define.asp?key=39783&dict=CALD
inbreeding
the mating of individuals or organisms that are closely related through common ancestry, as opposed to outbreeding, which is the mating of unrelated organisms. Inbreeding is useful in the retention ...

Random mating
incest
sexual relations between persons who, because of the nature of their kin relationships, are prohibited by law or custom from intermarrying. Because, cross-culturally, incest is more an emotional ...
http://search.britannica.com/search?ref=A01015&query=inbreeding&exact
Ни в каком языке мира inbreeding не применяется только по отношению к животным.
Incest не обьязательно ведет к появлению потомства, это просто - sexual relations. Это совершенно другой термин.
PS: Неужели в нашем колхозе школа была настолько лучше, что приходится объяснять высокообразованным модераторам такие элементарные вещи!?