The downside of sexual imprinting is the desensitization effect discovered by anthropologist Edward Westermarck: people of different sexes brought up together in the first years of life (normally) most often do not experience sexual attraction to each other in the future.
Westermark vs. Freud
This discovery is a serious argument against Freud’s concept. Sigmund Freud believed that members of the same family have a natural sexual attraction to each other, which causes society to impose a taboo (an undiscussed ban) on incest, and Westermarck proceeds from the opposite point of view, that the taboo has no natural basis and is an arbitrary public or personal decision. Independent research confirms Westermarck’s observations and interpretation, but many psychoanalysts continue to support Freud’s concept, arguing that taboo would be meaningless if family members did not have such an attraction.