Probability matching on a simple simulated foraging task:The effects of reward persistence and accumulation on choice behavior

Over a series of decisions between two or more probabilistically rewarded options, humans have a tendency to diversify their choices, even when this will lead to diminished overall reward. In the extreme case of probability matching, this tendency is expressed through allocation of choices in proportion to their likelihood of reward. Research suggests that this behaviour is an instinctive response, driven by heuristics, and that it may be overruled through the application of sufficient deliberation and self-control. However, if this is the case, then how and why did this response become established? The present study explores the hypothesis that diversification of choices, and potentially probability matching, represents an overextension of a historically normative foraging strategy. This is done through examining choice behaviour on a simple simulated foraging task, designed to model the natural process of accumulation of unharvested resources over time. Behaviour was then directly compared with that observed on a standard fixed probability task (cf. Ellerby & Tunney, 2017). Results indicated a convergence of choice patterns on the simulated foraging task, between participants who acted intuitively and those who took a more strategic approach. These findings are also compared with those of another similarly motivated study (Schulze, van Ravenzwaaij, & Newell, 2017)