nudism or naturism, practice of going without clothing in social settings, generally in mixed gender groups and for purposes of good health or personal comfort. Governed by a strict set of rules, the practice of nudism is purposely nonerotic and nonsexual. As a social and philosophical movement, nudism began in Germany in the early 20th cent. and spread throughout Europe between the two World Wars. It originated as a protest against strict Victorian codes of behavior and sought to alleviate the ignorance and shame caused by hiding the human body. Nudism also represented a challenge to the traditional dichotomy that celebrates nudity in artistic representation but condemns it as a practice in everyday life. Stressing nudism's supposed benefits to physical health and mental well-being, contemporary adherents of the movement maintain that its practice aids both exercise and relaxation while promoting stress relief, positive body image, and increased self-esteem.
In the United States, nudism as an organized movement began in 1929 with an upstate New York picnic organized by German immigrant Kurt Barthel and achieved some popularity in North America during the 1930s. Today nudism, which commonly includes sunbathing, swimming, sports, and other social activities, is usually practiced at clubs, camps, and parks and on special nude beaches. The Denmark-based International Naturist Federation, which has a membership of almost 500,000 in more than 60 countries, is devoted to worldwide nudist activities. The largest North American advocacy group, with a membership of nearly 50,000, is the Florida-based American Association for Nude Recreation, founded in 1931 and until 1995 known as the American Sunbathing Association.