Innate bisexuality (or predisposition to bisexuality) is a term introduced by Sigmund Freud (based on work by his associate Wilhelm Fliess), that expounds all humans are born bisexual but through psychological development (which includes both external and internal factors) become monosexual while the bisexuality remains in a latent state. There is no modern scientific consensus as to how biology influences sexual orientation (see biology and sexual orientation).