Appetitive motivation predicts the majority of personality and an ability measure: a comparison of BAS measures and a re-evaluation of the importance of RST Chris J. Jackson * , Luke D. Smillie School of Psychology, University of Queensland, Brisbane, Qld. 4072, Australia Received 1 July 2002; received in revised form 1 May 2003; accepted 20 June 2003 Abstract Our first study develops a measure of appetitive motivation and our second study compares several measures of GrayÕs (1987) behaviour activation system (BAS) in the prediction of the surface scales of personality. In particular, we were interested in determining the utility of the new appetitive motivation scale and DickmanÕs functional impulsivity scale. In comparison to other well-known measures, both scales were generally good predictors. We conclude that the appetitive motivation scale is a promising measure of BAS based upon construct validation. Contrary to previous studies which have suggested that BAS is a generally poor predictor of the surface scales of personality, we discovered appetitive motivation to be an important predictor of personality in general. Interestingly, the scale was also predictive of scores on the Baddeley reasoning test. Ó 2003 Elsevier Ltd. All rights reserved. Keywords: EPP; BAS; RST; Appetitive motivation; Approach; Impulsivity; Functional impuslivity 1. Introduction GrayÕs (1982, 1987) reinforcement sensitivity theory (RST) is a motivational theory of per- sonality with a biological basis. Implicit in RST is that it is at least a partial cause of personality (e.g., Corr, 2001; Gray, 1970; Matthews & Gilliland, 1999). The model consists of three systems but the focus of this study is constrained to the behaviour activation system (BAS). According to most recent clarification, the BAS mediates responses to appetitive stimuli and involves * Corresponding author. Tel.: +61-7-3365-6230; fax: +61-7-3365-4466. E-mail address: chrisj@psy.uq.edu.au (C.J. Jackson). 0191-8869/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2003.06.010 Personality and Individual Differences 36 (2004) 1627–1636 www.elsevier.com/locate/paid