Individual differences in evaluative conditioning and reinforcement sensitivity affect bet-sizes during gambling Geir Scott Brunborg ⇑ , Bjørn Helge Johnsen, Rune Aune Mentzoni, Helge Molde, Ståle Pallesen Department of Psychosocial Science, University of Bergen, Norway article info Article history: Received 23 September 2010 Received in revised form 16 December 2010 Accepted 20 December 2010 Keywords: Gambling Evaluative conditioning Conditionability Personality Behavioral inhibition system/behavioral approach system Bet-size Risk-taking abstract This study investigated the relationship between evaluative conditioning (EC), reinforcement sensitivity, and risk-taking on a simulated slot machine in a lab setting. Participants (51 female, 49 male, mean age 21.01 years [SD = 2.49] healthy adults) completed an EC paradigm with both negative unconditioned stimuli (negative EC) and positive unconditioned stimuli (positive EC). A negative EC by positive EC inter- action effect indicated that those who did not show negative EC or positive EC gambled with lower aver- age bet-size compared to the other participants. Scores on the fight-flight-freeze system (FFFS) and scores on the behavioral approach subscale Reward responsiveness (BAS-RR) were positively associated with average bet-size. An FFFS by BAS-RR interaction effect showed that participants who scored low on both BAS-RR and FFFS had lower bet-sizes compared to the other participants. These findings suggest that con- ditionability and reinforcement sensitivity play a role in gambling behavior. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction According to Blaszczynski and Nower’s (2002) ‘‘pathways model’’, behavioral conditioning plays an important role in the development and maintenance of problem gambling. The gambling environment is assumed to become associated with excitement through Pavlovian conditioning, and subsequently this excitement becomes a conditioned reinforcer for continued gambling (Sharpe & Tarrier, 1993). There are, however, individual differences in the acquisition of Pavlovian conditioning (condition- ability) (Eysenck, 1967). A decisive question that arises is whether individual differences in conditionability can help explain why some individuals develop gambling problems. Individuals who easily learn associations between previously neutral stimuli and positive stimuli may be more likely to develop gambling problems than others. Also, individuals who have difficulties learning associ- ations between previously neutral stimuli and negative stimuli may be more likely to develop gambling problems because they fail to associate gambling with the negative feelings associated with losing. One avenue for research in this area is to investigate how indi- vidual differences in conditionability are related to risk-taking in gambling. This is relevant to problem gambling since individuals who develop gambling problems usually gamble with higher risk compared to other gamblers (American Psychiatric Association, 2000). In one previous study we found that individuals who showed aversive autonomic Pavlovian conditioning showed greater risk avoidance on the Iowa Gambling Task (IGT) (Bechara, Damasio, Damasio, & Anderson, 1994) compared to individuals who did not show aversive conditioning (Brunborg et al., 2010). We concluded from our previous study that aversive conditionabil- ity may be associated with learning to avoid risky choices over time. Appetitive conditioning may also be important for understand- ing the role of individual differences in risk-taking, as gambling in- volves both aversive (losing) and appetitive (winning) stimuli. Aversive conditioning denotes the pairing of an initially neutral conditioned stimulus (CS) with an aversive unconditioned stimu- lus (US). Appetitive conditioning implies the pairing of a CS with an appetitive US. Aversive and appetitive conditioning may be studied simultaneously through evaluative conditioning (EC). One of the most common EC designs is the picture–picture paradigm (De Houwer, Thomas, & Baeyens, 2001). In this paradigm, pictures with neutral valence are evaluated before conditioning. Then the pictures are repeatedly paired with either a positive or a negative US, and subsequently the pictures are re-evaluated at post-condi- tioning (Levey & Martin, 1987). A recent meta-analysis including 214 single studies found that the overall effect size for EC was only in the medium range (Hofmann, De Houwer, Perugini, Baeyens, & 0191-8869/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2010.12.026 ⇑ Corresponding author. Address: Department of Psychosocial Science, University of Bergen, Christiesgate 12, 5020 Bergen, Norway. Tel.: +47 55 58 32 90; fax: +47 55 58 98 79. E-mail address: geir.brunborg@psysp.uib.no (G.S. Brunborg). Personality and Individual Differences 50 (2011) 729–734 Contents lists available at ScienceDirect Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid