Much controversy surrounds the assigning or distinguishing of some variations, especially since differences between groups in a society or between societies is often debated as part of either a person's "essential" nature or a socially constructed attribution. For example, there has long been a debate among sex researchers on whether sexual orientation is due to evolution and biology (the "essentialist" position), or a result of mutually reinforcing social perceptions and behavioral choices (the "constructivist" perspective). The essentialist position emphasizes inclusive fitness as the reason homosexuality has not been eradicated by natural selection. Gay or lesbian individuals have not been greatly affected by evolutionary selection because they may help the fitness of their siblings and siblings' children, thus increasing their own fitness through inclusive fitness and maintaining evolution of homosexuality. Biological theories for same gender sexual orientation include genetic influences, neuroanatomical factors, and hormone differences but research so far has not provided any conclusive results. In contrast, the social constructivist position argues that sexuality is a result of culture and has originated from language or dialogue about sex. Mating choices are the product of cultural values, such as youth and attractiveness, and homosexuality varies greatly between cultures and societies, which takes into account complexities such as sexual orientation changing in one's lifespan.[1]

  1. ^ DeLamater, John D.; Hyde, Janet Shibley (1998-01-01). "Essentialism vs. Social Constructionism in the Study of Human Sexuality". The Journal of Sex Research. 35 (1): 10–18.