Straight edge is a subculture of hardcore punk whose adherents refrain from using alcohol, tobacco, and other recreational drugs. It was a direct reaction to the sexual revolution, hedonism, and excess associated with punk rock. For some, this extends to not engaging in promiscuous sex, following a vegetarian or vegan diet, and not using caffeine or prescription drugs. The term was coined by the 1980s hardcore punk band Minor Threat in their song "Straight Edge".
Straight edge emerged from the late 1970s punk scene. Since then, a wide variety of beliefs and ideas have been incorporated into straight edge including vegetarianism, animal rights, communism and Hare Krishna beliefs. In many parts of the United States, straight edge is treated as a gang by law enforcement officials. However, a 2006 study suggested that only a small minority of the people who identify as straight edge are violent.