Transitive inference and awareness in humans.

Thirty-nine participants performed a transitive inference task. During training, they were shown six pairs of imaginary sports teams and learnt which team was better in each pair. The pairs of teams were adjacent members of a seven-term series of team rankings (A-G). The participants were not explicitly informed of this underlying stimulus hierarchy. Once a participant reached the training criterion, they were tested on the six training pairs and three novel pairs (BD, CE, and DF) that required the participant to make a transitive inference. The participants completed a post-experimental questionnaire that measured their awareness of the stimulus hierarchy. A more-aware group and a less-aware group were created from answers to the questionnaire. The less-aware group were significantly less accurate than the more-aware group on some training pairs and all three novel pairs, and the less-aware group's pattern of performance bore similarities to non-human animal performance.