The origins of bodily sex are well understood but consensus on origins for gender are missing. While gonadal sex and sexual orientation are accepted as emanating from genetic and hormonal templates, gender’s existence, when it is acknowledged, currently has so far emanated from either social origins or a nebulous ‘somewhere’ in the brain. Although the characteristics of sex-related behavior relative to the physicality of reproduction are clearly dimorphic, other cognitive behaviors relative to reproduction have not been explicitly identified and presented. This article synthesizes important research to present a biological location of gender as opposed to sex. These cognitive behaviors can be differentially linked with reproduction throughout the lifespan. A physiological location for gender in the human phenotype may help advance this research further.

The origins of bodily sex are well understood, but consensus on any origins for gender is absent. While gonadal sex and sexual orientation are accepted as emanating from genetic and hormonal templates, the existence of gender, when acknowledged, currently has so far originated either from strictly social origins, a nebulous ‘somewhere’ in the brain or from some combination of sources. We propose gender identity emanates from previously unrecognized universal early stable dimorphic sex differences in cognitive signalling relevant to reproduction, and removed from the behaviors widely accepted as a sex/gender mosaic. The neural networks associated with these behaviors thus provide a biological or anatomical location for gender as opposed to sex.