Orientation sexuelle ou préférences sexuelles ?

The objective of this article is to identify in humans and mammals in general the neurobiological processes for sexual orientation and the development of sexual preferences, and to assess the importance of each. The data was collected from a review of the literature concerning the neurobiology of sexual orientation and preferences. In non-primate mammals (rodents, caninae, felidae, bovidae, equidae, etc.), there are several different types of process and situation involved in the development of preferences for certain partners over others. There are also neurobiological processes that are specifically arranged for heterosexual orientation; mainly the olfactory circuits that detect and process sexual pheromones. But in hominids (orang-utans, gorillas, chimpanzees, bonobos, humans), the pheromone receptor genes are impaired, thus reducing the functional importance of these sexual orientation processes. However, the processes underpinning sexual preferences are more important. This is why, in human beings, the impaired olfactory processes and sexual pheromones only have a secondary influence, and are combined with several other factors (genes, hormones, conditioning, sexual preferences, emotions, cognitive processes, cultural context). The relative importance of each of these factors is dependent both on individual physiological characteristics, personal experience and aspects of the sociocultural environment. This complex combination of several interacting factors (including the residual activity of the olfactory processes for sexual orientation) is thought to be the at the origin of development of sexual preferences, different for each individual.