Influence of interpersonal abilities on social decisions and their physiological correlates

Abstract The concept of interpersonal abilities refers to performance measures using social stimuli which quantify individual differences in social competences and skills that are at the core of interpersonal communication such as the abilities to perceive and remember faces and the abilities to recognize and express emotions. The aim of this dissertation was to examine the influence of interpersonal abilities on social decisions. A particular focus lay on the quantification of individual differences in brain-behavior relationships associated with processing interpersonally relevant stimuli. Study 1 added to existing evidence on brainbehavior relationships, specifically between psychometric constructs of face cognition and event-related potentials (ERPs) associated with different stages of face processing (encoding, perception, and memory) in a familiarity decision. Our findings confirm a substantial relationship between the N170 latency and the early-repetition effect (ERE) amplitude with three established face cognition ability factors. The shorter the N170 latency and the more pronounced the ERE amplitude, the better is the performance in face perception and memory and the faster is the speed of face cognition. Study 2 found that the ability to recognize fearful faces as well as the general spontaneous expressiveness during social interaction are linked toThe concept of interpersonal abilities refers to performance measures using social stimuli which quantify individual differences in social competences and skills that are at the core of interpersonal communication such as the abilities to perceive and remember faces and the abilities to recognize and express emotions. The aim of this dissertation was to examine the influence of interpersonal abilities on social decisions. A particular focus lay on the quantification of individual differences in brain-behavior relationships associated with processing interpersonally relevant stimuli. Study 1 added to existing evidence on brainbehavior relationships, specifically between psychometric constructs of face cognition and event-related potentials (ERPs) associated with different stages of face processing (encoding, perception, and memory) in a familiarity decision. Our findings confirm a substantial relationship between the N170 latency and the early-repetition effect (ERE) amplitude with three established face cognition ability factors. The shorter the N170 latency and the more pronounced the ERE amplitude, the better is the performance in face perception and memory and the faster is the speed of face cognition. Study 2 found that the ability to recognize fearful faces as well as the general spontaneous expressiveness during social interaction are linked to prosocial choices in several socio-economic games. Sensitivity to the distress of others as well as spontaneous expressiveness seem to foster reciprocal interactions with prosocial others. Study 3 confirmed the model of strong reciprocity in that prosociality drives negative reciprocity in the ultimatum game. Using multilevel structural equation modeling (SEM) in order to estimate brain-behavior relationships of fairness preferences, we found strong reciprocators to show more pronounced relative feedback-negativity (FN) amplitude in response to the faces of bargaining partners. Thus, the results of this dissertation suggest that established individual differences in behavioral measures of interpersonal ability are partly due to individual differences in brain mechanisms.