Formal modelling of interpersonal processes

Capturing the complexity of interpersonal dynamics - which results from the approach and avoidance motives of two individuals in dyadic interaction and unfolds simultaneously on multiple time levels - is a scientific challenge. In line with the call to capture complexity in psychological research through formal modelling, the aim of this project is to investigate the underlying mechanisms of the emergence and maintenance of interpersonal relationships using evolutionary game theory.

After formalising interpersonal situations on the basis of the affiliative motives of the interaction partners, a relational state space was constructed that reflects the relational possibilities available to the interaction partners in the current state of their interpersonal relationship. This makes it possible to model the development of an interpersonal relationship as a curve through the relational space, the path of which is determined by positive and negative reinforcement.

Depending on the motives of both interaction partners, three qualitatively different interpersonal dynamics emerge: (1) global stability with only one relationship attractor (e.g. an interpersonal relationship of pure friendliness in the long term), (2) bistability with two mutually exclusive relationship attractors (e.g. either pure friendliness or pure distance) and (3) cyclicality with periodic trajectories in the relationship space (e.g. oscillation between friendliness and distance). The formal model, which is based on empirically supported psychological constructs, generates the familiar pattern of interpersonal complementarity. In addition, new interpersonal patterns have emerged that may point to some underlying mechanisms of interpersonal maintenance of psychopathology.