Editing Psilocybin (section)

====Set and setting and moderating factors====
The effects of psilocybin are highly variable and depend on the mindset and environment in which the user has the experience. factors commonly called [[set and setting]]. In the early 1960s, [[Timothy Leary]] and his Harvard colleagues investigated the role of set and setting in psilocybin's effects. They administered the drug to 175 volunteers (from various backgrounds) in an environment intended to be similar to a comfortable living room. 98 of the subjects were given questionnaires to assess their experiences and the contribution of background and situational factors. Those who had prior experience with psilocybin reported more pleasant experiences than those for whom the drug was novel. Group size, dosage, preparation, and expectancy were important determinants of the drug response. In general, those in groups of more than eight felt that the groups were less supportive and their experiences less pleasant. Conversely, smaller groups (fewer than six) were seen as more supportive and reported more positive reactions to the drug in those groups. Leary and colleagues proposed that psilocybin heightens suggestibility, making a user more receptive to interpersonal interactions and environmental stimuli.<ref name=Leary1963/> These findings were affirmed in a later review by Jos ten Berge (1999), who concluded that dosage, set, and setting are fundamental factors in determining the outcome of experiments that tested the effects of psychedelic drugs on artists' creativity.<ref name=Berge1999/>