A concept popularized by Talcott Parsons. He argued (in The Social System, 1951) that whilst disease involves bodily dysfunction, being sick—that is, being identified and accepted as ill—is a role governed by social expectations, of which he listed four. First, exemption from normal social role responsibilities: this exemption must be legitimated by some authority, often a medical practitioner. Second, exemption from responsibility for being ill, which means that the sick must be looked after. Third, since sickness is deemed undesirable, the sick are obliged to want to get better; and also, fourthly, to seek technically competent help and co-operate in trying to get better.
The concept draws attention to the social regulation of illness: to the mechanisms that guarantee the compliance of sick persons, help to restore them to health, and ensure that only the genuinely sick are exempt from normal responsibilities. It also provides a means of analysing the motivational factors involved in illness. Indeed, Parsons suggested that because of these motivational components (he was influenced here by Freudian theorizing), illness could be considered a special form of deviance, functional to the social system in directing deviant tendencies away from group formation, solidarity, and successful claims to legitimacy.
Critics have questioned the universality of Parsons's specification of the expectations governing the sick role, the extent to which illness is motivated, the model's relevance to long-term sickness, and his focus on what is functional for society. None the less, the concept of the sick role has been central to sociological thinking about health and illness, and its importance would be hard to overestimate.