The use of alcohol and other psychoactive drugs is deeply intertwined with social behaviour. As indicated by earlier chapters, drinking, smoking and illicit drug use all become increasingly commonplace as young people grow older. In addition, the use of licit and illicit drugs is widely viewed as a hallmark of attractiveness, maturity and sociability. Because of the highly social nature of much of their use, alcohol and other drugs are frequently associated with sexual behaviour. Psychoactive drugs are associated with sexuality for two broad reasons. The first of these is the cultural and social connections between the use of such substances and sexual encounters. Very often drinking or other types of drug use may simply be the conventional accompaniments or precursors of dating and sexual activity. The second reason is that drugs have and are widely believed to have effects upon sexual arousal and performance.