Heterosexuality

Heterosexuality is romantic attraction, sexual attraction or sexual behavior between persons of the opposite sex or gender. As a sexual orientation, heterosexuality is "an enduring pattern of emotional, romantic, and/or sexual attractions" to persons of the opposite sex; it "also refers to a person's sense of identity based on those attractions, related behaviors, and membership in a community of others who share those attractions."[1][2] Someone who is heterosexual is commonly referred to as straight.

Along with bisexuality and homosexuality, heterosexuality is one of the three main categories of sexual orientation within the heterosexual–homosexual continuum.[1] Across cultures, most people are heterosexual, and heterosexual activity is by far the most common type of sexual activity.[3][4]

Scientists do not know the exact cause of sexual orientation, but they theorize that it is caused by a complex interplay of genetic, hormonal, and environmental influences,[5][6][7] and do not view it as a choice.[5][6][8] Although no single theory on the cause of sexual orientation has yet gained widespread support, scientists favor biologically-based theories.[5] There is considerably more evidence supporting nonsocial, biological causes of sexual orientation than social ones, especially for males.[3][9][10]

The term heterosexual or heterosexuality is usually applied to humans, but heterosexual behavior is observed in all other mammals and in other animals, as it is necessary for sexual reproduction.