Reward uncertainty and the aversion-attraction dilemma

Uncertainty is a common feature of the real world for many organisms, including humans. However, uncertainty is also the source of a constant dilemma that has to be solved by organisms to maintain their safety: avoiding it when possible while being ready to deploy some effort to counter its unavoidable consequences. When an uncertain outcome is crucial for survival (e.g., food), it may seem obvious to say that the individual ought to be invested in reward procurement rather than giving up. Many experimental studies confirm that a conditioned stimulus (CS) unreliably predictive of food delivery generates higher response rates in various animal species than the same CS reliably predictive of food on each trial. Here, the crux issue is to try to understand the psychological mechanism responsible for the investment in a reward-related task whose pay-off is not guaranteed. Is it aversion-induced frustration? Or is it motivational attraction resulting from incentive salience? I show that neither of these two theories is fully convincing. I argue that uncertain individuals “ hope ” for reliable CS-Reward associations instead of being focused on aversive uncertainty or attractive reward per se.