A well-established sense of gender does not depend on sexual object choice but on a sense of security in belonging to the gender correlated to one's biological sex. Cross-gender identifications are often found in heterosexual couples who show a marked reversal of conventional gender norms and whose typical interaction constitutes a shared defence against their mutual lack of gender security. Both partners are ‘possessed’ by the contrasexual archetype (anima and animus) and have been unable to integrate their contrasexual potential. Three aetiological factors seem to predispose both men and women towards cross-gender identification: an over-close relationship with the parent of the opposite sex, a negative identification with the parent of the same sex, and inappropriate use by their mothers as substitute caretakers (‘narcissistic objects’). In both sexes masculinity is idealized while femininity is denigrated.