Gender Identity

Gender identity is the personal sense of one's own gender.[1] Gender identity can correlate with assigned sex at birth or can differ from it.[2] All societies have a set of gender categories that can serve as the basis of the formation of a person's social identity in relation to other members of society.[3]

In most societies, there is a basic division between gender attributes assigned to males and females,[4] a gender binary to which most people adhere and which includes expectations of masculinity and femininity in all aspects of sex and gender: biological sex, gender identity, and gender expression.[5] Some people do not identify with some, or all, of the aspects of gender assigned to their biological sex;[6] some of those people are transgender, non-binary or genderqueer. Some societies have third gender categories.

Core gender identity is usually formed by age three.[7][8] After age three, it is extremely difficult to change,[7] and attempts to reassign it can result in gender dysphoria.[9] Both biological and social factors have been suggested to influence its formation.