An Animal Model of Human Gambling Based on Pigeon Suboptimal Choice

When humans gambling they choose an outcome that has high value but a low probability of occurrence over a more favourable high probability outcome of lower value (not gambling). Similarly, pigeons show a preference for an alternative that occasionally provides a signal for reinforcement over a more optimal alternative that always provides a signal for a lower probability of reinforcement. Two mechanisms appear to be responsible for this suboptimal behaviour: the signal for non-reinforcement (losing) appears to result in little or no inhibition and the probability of the signal for reinforcement is relatively unimportant. Human gambling behaviour appears to be controlled by similar mechanisms. Also, we have found that as with human gambling, pigeons that are more motivated to win choose less optimally. Furthermore, pigeons exposed to an enriched environment choose more optimally than those normally housed. Similar to humans, individual differences in impulsivity by pigeons predict attraction to the suboptimal alternative by pigeons. These findings may have implications for the treatment of humans who have problems with gambling behaviour.