Nudity is the state of being in which a human is without clothing. While estimates vary, for the first 90,000 years of pre-history, anatomically modern humans were naked, having lost their body hair and living in hospitable climates. As humans became behaviorally modern, body adornments such as jewelry, tattoos, body paint and scarification became part of non-verbal communications, indicating a person's social and individual characteristics. Indigenous peoples in warm climates used clothing for decorative, symbolic or ceremonial purposes but were often nude, having neither the need to protect the body from the elements nor any conception of nakedness being shameful. In many societies, both ancient and contemporary, children might be naked until the beginning of puberty. Women may not cover their breasts if they were associated with nursing babies more than with sexuality.
In the ancient civilizations of the Mediterranean, from Mesopotamia to the Roman Empire, proper attire was required to maintain social standing. The lower classes might possess a single piece of cloth that was wrapped or tied to cover the lower body; the lowest classes including slaves might be naked. However, through much of Western history until the modern era, people of any status were also unclothed by necessity or convenience when engaged in labor and athletics; or when bathing or swimming. Such functional nudity occurred in groups that were usually but not always segregated by sex. Although improper dress might be socially embarrassing, the association of nudity with sin regarding sexuality began with Judeo-Christian societies, spreading through Europe in the post-classical period. Traditional clothing in temperate regions worldwide also reflect concerns for maintaining social status and order, as well as by necessity due to the colder climate. However, societies such as Japan and Finland maintain traditions of communal nudity based upon the use of baths and saunas that provided alternatives to sexualization.
The spread of Western concepts of modest dress was part of colonialism, and continues today with globalization. Contemporary social norms regarding nudity reflect cultural ambiguity towards the body and sexuality, and differing conceptions of what constitutes public versus private spaces. Norms relating to nudity are different for men than they are for women. Individuals may intentionally violate norms relating to nudity; those without power may use nudity as a form of protest, and those with power may impose nakedness on others as a form of punishment.
While the majority of contemporary societies require clothing in public, some recognize non-sexual nudity as being appropriate for some recreational, social or celebratory activities, and appreciate nudity in the arts as representing positive values. A minority within many countries assert the benefits of social nudity, while other groups continue to disapprove of nudity not only in public but also in private based upon religious beliefs. Norms are codified to varying degrees by laws defining proper dress and indecent exposure.