Gender and sexuality are not just personal identities; they are social identities. They arise from our relationships to other people, and they depend upon social interaction and social recognition. As such, they influence how we understand ourselves in relation to others. In sociology, we make a distinction between sex and gender. Sex are the biological traits that societies use to assign people into the category of either male or female, whether it be through a focus on chromosomes, genitalia or some other physical ascription. When people talk about the differences between men and women they are often drawing on sex - on rigid ideas of biology - rather than gender, which is an understanding of how society shapes our understanding of those biological categories.