1. The belief that males and females are born with distinctively different natures, determined biologically rather than culturally. This involves an equation of gender and sex. The term is often used pejoratively by constructionists (see constructionism), but strategic essentialism is a common activist strategy, and biological essentialism surfaces in the insistence of some feminists that the physical facts of sexual difference do have entailments. See also difference model; essentialism.
2. The belief that gay people are born gay (a form of biological determinism) and/or that there is a distinctive ‘gay sensibility’.
3. The attribution of a homogeneous identity to a labelled group (such as women or gay males), ignoring differences within it. This can be either a naïve essentialism (for instance, labelling people in widely-different cultures and historical periods simply as ‘gay’), or a politically-motivated strategic essentialism.