Testing a Curvilinear Relationship between Chemosensory Responsivity and Avoidance Motivation

Abstract

Approach and avoidance motivations underlie much of human behavior. This paper examines an as-yet under-investigated contributor to those motivations – chemosensory responsivity. Based on the logic that the chemical senses help the perceiver to detect ecological threats, we predicted that individual differences in chemosensory responsivity may predict approach-avoidance motivations. Specifically, because people with below or above average sensory responsivity may be unable to reliably discriminate threats from nonthreats in their environment, they may consequently adopt a compensatory shift from approach to avoidance motivations. The current project tested for such a curvilinear relationship between chemosensory responsivity and approach-avoidance motivation. In Study 1, chemosensory responsivity was indexed by combined performance on the University of Pennsylvania Smell Identification Test with detection of bitterness in a taste strip containing phenylthiocarbamide. Approach versus avoidance motivation was measured with the line bisection task. Study 2 provided a conceptual replication using self-report measures. Study 3 used a new psychophysical measure directly assessing olfactory detection thresholds, and extended the investigation to perceptions of threat-related facial expressions. In all three studies, results revealed a quadratic effect of sensory responsivity on approach-avoidance motivation, such that participants scoring relatively low or relatively high on sensory responsivity displayed higher levels of avoidance-related cognition. Elucidating the link between sensory processing and general motivational orientations has the potential to inform understanding of higher-order social cognitive functioning.