The role of interindividual differences in task-based approach-avoidance behavior

Abstract

Approach and avoidance are evolutionary highly conserved mechanisms of survival, realized by approaching rewarding and avoiding punishing stimuli in one’s environment. In the laboratory, approach-avoidance behaviors are often measured using experimental tasks. In this thesis, the relationship of interindividual differences with behavioral outcomes of those so-called approach-avoidance tasks was investigated. Firstly, the literature on approach-avoidance tasks and interindividual differences was systematically reviewed. Secondly, the influences of the stress mediators cortisol and noradrenaline as well as self-reported interindividual differences was investigated with a pharmacologically validated approach-avoidance conflict paradigm in a double-blind study with healthy participants. Lastly, the approach-avoidance conflict paradigm was compared to two more established approach-avoidance tasks, the joystick and manikin tasks, in their efficacy to relate to self-reported interindividual differences. Both, systematic review and the conducted research indicates that relationships between task-based approach-avoidance measures and interindividual differences are ambiguous in nature with few exceptions, e.g. in the case of specific phobias. The approach-avoidance conflict paradigm was not affected by the stress mediators, but related to self-reported behavioral inhibition, physical aggression and verbal aggression whereas the joystick and manikin tasks did not. Even those findings appear to be ambiguous, as while interactions of aggression were found in the comparison study, they were not in the pharmacological study, possibly due to a lack of power. Internal consistency measures of all three tasks indicated subpar consistencies for joystick and manikin task and robust consistencies of approach-avoidance conflict paradigm measures. Potential reasons such as differences in the level of abstraction between task and trait measures, particularities of the task designs as well as ideas to resolve or improve them, for example, by employing more ecologically valid designs, are discussed.