A control-theory reward-based approach to behavior modification in the presence of social-norm pressure and conformity pressure

This paper takes a control engineering perspective on the use of rewards to modify the behavior of a person. We consider the particular scenario where a parent is trying to coerce her child to get more physical exercise. The goal is to determine a reward sequence that drives the child's behavior to some desired value. The main novelty of this paper is the introduction of social-norm effects (arising from social pressure due to, say, a teacher) and conformity effects (arising from interactions that the child has with a friend). The social-norm effect, being uni-directional, acts as a disturbance, while the conformity effect, which is bi-directional, creates an extra dynamic feedback loop. We model the psychological state of the child and friend using a combination of psychological theories (the “theory of planned behavior,” “cognitive dissonance theory,” and “overjustification theory”), and we use classical control tools to design an output-feedback controller that achieves the setpoint tracking objective. Robustness issues are also considered.