The functionalist perspective on deviance: Is based on the concept that what is regarded as deviant behavior by one person or social group may not be so regarded by other persons or social groups. Relies on the ideas of what is good and what is bad to define illness, but also incorporates biological components. Stresses societal-level processes, systems, equilibrium, and interrelationships, representing a homeostatic approach to deviance. Purely focuses on health and well-being and disregards other forms of deviance, such as criminality.