Androphilia and gynephilia are terms used in behavioral science to describe sexual orientation, as an alternative to a gender binary homosexual and heterosexual conceptualization. Androphilia describes sexual attraction to men or masculinity; gynephilia describes the sexual attraction to women or femininity.Ambiphilia describes the combination of both androphilia and gynephilia in a given individual, or bisexuality.
The terms are objectively used for identifying a person's object of attraction without attributing a sex assignment or gender identity to the person. This can avoid bias inherent in normative conceptualizations of human sexuality, avoid confusion and offense when describing people in non-western cultures, as well as when describing intersex and transgender people, especially those who are nonbinary or otherwise falling outside the gender binary.
In a discussion of homosexuality, sexologist Magnus Hirschfeld divided men into four groups: paedophiles, who are most attracted to prepubescent youth, ephebophiles, who are most attracted to youths from puberty up to the early twenties; androphiles, who are most attracted to persons between the early twenties and fifty; and gerontophiles, who are most attracted to older men, up to senile old age. According to Karen Franklin, Hirschfeld considered ephebophilia "common and nonpathological, with ephebophiles and androphiles each making up about 45% of the homosexual population."