The National Survey of Sexual Attitudes and Lifestyles (NATSAL) is the name given to a series of face-to-face surveys of people in the United Kingdom regarding their sexual behaviour and patterns. The three rounds of interviews completed to date are NATSAL I (1990–91) and NATSAL II (2000-01) and NATSAL III (2010–12). The results are widely used in research and policy making. NATSAL's principal investigator is Anne Johnson, a professor at University College, London. The 2010 survey revealed, among other things, that British people are having sex less often than they did 20 years ago.