Many theories of behavior pivot around a particular human tendency: We’re keen responders to positive and negative reinforcements, or zippy calculators of our self-interest, or lumpy duffel bags of psychosexual conflicts. SDT, by contrast, begins with a notion of universal human needs. It argues that we have three innate psychological needs—competence, autonomy, and relatedness. When those needs are satisfied, we’re motivated, productive, and happy. When they’re thwarted, our motivation, productivity, and happiness plummet.
