is the range of characteristics pertaining to, and differentiating between, masculinity and femininity. Depending on the context, these characteristics may include biological sex
(i.e. the state of being male, female
or an intersex variation
which may complicate sex assignment
), sex-based social structures (including gender roles and other social roles), or gender identity. Some cultures have specific gender roles that can be considered distinct from male and female, such as the hijra (chhaka) of India and Pakistan.
Sexologist John Money introduced the terminological distinction between biological sex and gender as a role in 1955. Before his work, it was uncommon to use the word gender
to refer to anything but grammatical categories. However, Money's meaning of the word did not become widespread until the 1970s, when feminist theory embraced the concept of a distinction between biological sex and the social construct
of gender. Today, the distinction is strictly followed in some contexts, especially the social sciences and documents written by the World Health Organization (WHO).
In other contexts, including some areas of social sciences, gender
or replaces it. For instance, in non-human animal research, gender
is commonly used to refer to the biological sex of the animals. This change in the meaning of gender can be traced to the 1980s. In 1993, the USA's Food and Drug Administration (FDA) started to use gender
instead of sex
. Later, in 2011, the FDA reversed its position and began using sex
as the biological classification and gender
as "a person's self representation as male or female, or how that person is responded to by social institutions based on the individual's gender presentation
The social sciences have a branch devoted to gender studies. Other sciences, such as sexology and neuroscience, are also interested in the subject. While the social sciences sometimes approach gender as a social construct, and gender studies particularly do, research in the natural sciences
investigates whether biological differences in males and females influence the development of gender in humans; both inform debate about how far biological differences influence the formation of gender identity. In the English literature, there is also a trichotomy between biological sex, psychological gender, and social gender role. This framework first appeared in a feminist paper on transsexualism in 1978.