Historical concepts of mental illness.

People are social creatures who learn how to behave appropriately in families and communities. What is considered appropriate, however, depends on a host of factors, including historical period, culture, geography, and religion. Thus, what is valued and respected changes over time, as do sociocultural perceptions of aberrant or deviant behavior. How deviancy is treated depends a great deal on the extent of the deviancy—is the person dangerous, a threat to self or to the community, in flagrant opposition to community norms, or is the person just a little odd? How the community responds also depends on its beliefs as to what causes aberrant behavior. Supernatural beliefs in demons, spirits, and magic were common in preliterate societies; in the medieval Western world, Christians believed that the devil was in possession of deranged souls. Hence, "the mad" were subjected to cruel treatments justified by the idea of routing out demons or the devil. For centuries, the prevailing explanation for madness was demonic possession.