A purity test is a self-graded survey that assesses the participants' supposed degree of innocence in worldly matters (sex, drugs, deceit, and other activities assumed to be vices), generally on a percentage scale with 100% being the most and 0% being the least pure. Online purity tests were among the earliest of Internet memes, popular on Usenet beginning in the early 1980s. However, similar types of tests circulated under various names long before the existence of the Internet.