Masculinity is a set of qualities, characteristics or roles generally considered typical of, or appropriate to, a man. It can have degrees of comparison: "more masculine", "most masculine'". The opposite can be expressed by terms such as "unmanly'" or epicene. A near-synonym of masculinity is virility (from Latin vir, man). Constructs of masculinity vary across historical and cultural contexts. The dandy, for instance, was regarded as an ideal of masculinity in the 19th century, but is considered effeminate by modern standards.
Academic study of masculinity underwent a massive expansion of Interest in the late 1980s and early 1990s, with courses in the United States dealing with masculinity rising from 30 to over 300 Although in a sense all scholarship had previously been masculine studies, the new approach to the study of the characteristics of men was prompted by feminist, LGBT and racial equality campaigners. This has led to the Investigation of the intersection of masculinity with other axes of social discrimination and also to the use of concepts from other fields - such as feminism's model of the social construct of Gender.
The extent to which masculinity is a result of nature or nurture, a matter of what someone is born with or how they are socialised, has been the subject of much debate. Genome research has yielded much Information about the development of masculine characteristics and the process of sexual differentiation specific to the reproductive system of human beings.. The SRY gene on the Y chromosome, which is critical for male sexual development, activates SOX9. SOX9 associates with Sf1 to increase the level of Anti-Müllerian hormone to repress female development while activating and forming a feed-forward loop with FGF9, which creates the testis cords and is responsible for the proliferation of sertoli cells. The activation of SRY interferes with the process of creating a female, causing a chain of events that leads to testes formation, androgen production, and a range of pre-natal and post-natal hormonal effects. There is an extensive debate about how children develop Gender identities. On the nature side of the debate, it is argued that masculinity is inextricably linked with the male Body. In this view, masculinity is something that is associated with the biological male sex and having male genitalia, for instance, is regarded as a key aspect of masculinity.
Others have suggested that while masculinity may be influenced by biological factors, it is also culturally constructed. As such, masculinity is not restricted to men and can, in fact, be female when women display behavior, traits and physical attributes that are considered masculine in a given historical and social context. Proponents of this view argue that women can become men hormonally and physically and that many aspects that are assumed to be natural are linguistically and therefore culturally driven. On the nurture side of the debate, it is argued that masculinity does not have a single source of origin or creator such as the media, certain institutions, or certain groups of people. While the military, for example, has a vested Interest in constructing and promoting a specific Form of masculinity, it does not create it from scratch and masculinity has influenced the creation of the military in the first place. However, as an example of socialization into masculinity, facial Hair has been linked to masculinity through Language, in such forms as stories about boys becoming men when they start to shave.