Final answer:
Homosexuality is considered a normal variant of human sexuality by contemporary scientific and social understanding, although cultural responses to sexual diversity vary widely. The historical view of heteronormativity, which considered heterosexuality as the natural sexual orientation, has been challenged by recent research and advocacy.
Step-by-step explanation:
The concept in question pertains to the normalcy of sexual orientation, specifically homosexuality. It is indeed true that different cultures have varied historical and contemporary responses to sexual diversity. The idea of heteronormativity, which implies that heterosexuality is the default or 'natural' state of human sexuality, has been significantly challenged by both scientific research and the growth of the global LGBTQIA+ movement. In some cultures, there is a greater acceptance of multiple forms of sexuality, and the notion of a strict sexual identity doesn't necessarily apply. However, this does not mean that these societies are always liberal with respect to sexuality. It is common in many of these societies for individuals to engage in same-sex relationships or activities under certain conditions while still adhering to societal expectations of marrying someone of the opposite sex and having children.