A Trait Conceptualization of Reward-Reactivity: Psychometric Properties of the Appetitive Motivation Scale (AMS)

Abstract

The Appetitive Motivation Scale (AMS; Jackson & Smillie, 2004) represents a recent attempt to conceptualize individual differences in the functioning of Gray's (1981) Behavioral Activation/Approach System (BAS). In this paper we subject the AMS to psychometric scrutiny via factor analysis, item response theory (IRT) analysis, and concurrent construct validation. In Study 1 (N = 1,366 university students, 53% male), results from factor analysis (FA) and IRT led to the removal of several problematic items from the scale. The revised AMS was shown to have improved unidimensional structure and item properties. In Study 2 (N = 122 university students, 20% male), correlational data and factor anal..