Tomboy

A tomboy is typically described as a girl who behaves according to the gender role of a boy, though the term is also applied to adult women. This social phenomenon typically manifests itself through these characteristics:
 * The wearing of typically masculine-oriented types of clothes.
 * The practice of games and activities (often physical in nature), that are typically considered to be the domain of boys.
 * The preference of school subjects typically considered to be the domain of boys (i.e. mathematics, the hard sciences)
 * The preference to befriend boys rather than other girls.

Word history
The word has been recorded to be used in the English language since 1553, primarily to describe a "rude, boisterous boy," from Tom (a common boys' name as in 'Tommy', meaning soldier) + boy; the meaning "bold or immodest woman" is attested from 1579; the present use is first recorded in 1592.

In modern society
Historically, tomboys have been defined, as suggested in the examples mentioned above, by "boyish" behavior (like more physically active, technological, and scientific interests) and wearing boys' clothing. In recent times, as the use of traditionally female clothing such as dresses, blouses and skirts steadily declines among Western females, the distinction has become more and more one of behavior. A general increase in the popularity of woman's sporting events (see Title IX), and other activities that were traditionally male-dominated, is today broadening tolerance and lessening the impact of "tomboy" as a pejorative.

Childhood gender roles are handled somewhat differently for tomboys and girlish boys. Gender scholar Judith 'Jack' Halberstam has claimed that while the defying of gender roles is often tolerated in young girls, older girls and adolescents who display masculine traits are often repressed and punished.

Causes
There is little study of the causality of the phenomenon, since it has been considered, first and foremost, to be a phase one might go through in early years of life. One theory of a possible cause is that a girl who spends her childhood and/or adolescence in an environment where the male presence predominates, she simply lacks any feminine role models. However, this hypothesis has been challenged by one report from the Avon Longitudinal Study of Parents and Children which suggests that the state is heavily influenced by genetic and prenatal factors.