Differential outcomes effect in children: Demonstration and mechanisms

The present paper reports three experiments that examine the role of sample stimulus-outcome (S-O) and of comparison or choice response stimulus-outcome (R-O) relations in the differential outcomes discrimination learning of five-year-old children. In these experiments, S-O relations or R-O relations were maintained or removed across two different conditional discrimination tasks. The results indicated that only children who received training in either S-O or R-O relations showed positive transfer between the conditional discriminations. These data support a two-process (‘outcome expectancy’) account of differential outcomes phenomena in which each sub-problem in a discriminative conditional choice task has its own unique reinforcer, but they also indicate that both unique sample-outcome associations and unique choice-outcome associations are important contributing features to enhanced discriminative learning under differential outcomes procedures in humans. Comparison to a control in Experiments 2 and 3 indicated that merely having had previous experience with the stimuli or having previously discriminated the stimuli did not contribute to cross-discrimination transfer in the absence of prior explicit association between those stimuli and the specific differential outcomes.