Conspecific presence reduces pigeons’ suboptimal choice

Abstract

According to Zajonc’s (1965) motivation based theory, the presence of a conspecific should increase motivation and the effect of an increase in motivation should depend on the nature of the target behavior. If the target behavior is already in the animals repertoire, the presence of a conspecific should increase the target behavior. If, however, the target behavior needs to be acquired, it should retard its acquisition. There is evidence that pigeons will choose suboptimally when given a choice between a 20% chance of signaled reinforcement and a 50% chance of unsignaled reinforcement. Under these conditions, once a preference is found, Zajonc’s theory suggests that the presence of a conspecific should increase suboptimal choice. However, there is also evidence that social experience by pigeons outside the experimental context reduces suboptimal choice. In the present experiment, pigeons performed this task either in the presence of a conspecific or without a conspecific present. Inconsistent with Zajonc’s theory, the results indicated that pigeons that performed the task in the presence of a conspecific chose suboptimally less often than pigeons that performed the task on their own. The results suggest that the presence of a conspecific may provide an alternative source of reinforcement, thus replacing some of the effect of the conditioned stimulus provided by the signal for reinforcement. Further testing with increased experimental sample size is recommended to confirm these preliminary findings.