The American Psychological Association states that "[s]exual orientation refers to an enduring pattern of emotional, romantic, and/or sexual attractions to men, women, or both sexes" and that "[t]his range of behaviors and attractions has been described in various cultures and nations throughout the world. Many cultures use identity labels to describe people who express these attractions. In the United States, the most frequent labels are lesbians (women attracted to women), gay men (men attracted to men), and bisexual people (men or women attracted to both sexes). However, some people may use different labels or none at all". They additionally state that sexual orientation "is distinct from other components of sex and gender, including biological sex (the anatomical, physiological, and genetic characteristics associated with being male or female), gender identity (the psychological sense of being male or female), and social gender role (the cultural norms that define feminine and masculine behavior)". According to psychologists, sexual orientation also refers to a person’s choice of sexual partners, who may be homosexual, heterosexual, or bisexual.