Collaborative inhibition effect: the role of memory task and retrieval method

It is well established that the recall of collaborative groups is lower than the pooled recall of an equal number of lone individuals-the collaborative inhibition effect (Weldon and Bellinger, J Exp Psychol Learn Memory Cogn 23(5):1160-1175, 1997). This is arguably the case because group members have conflicting retrieval strategies that disrupt each other's recall-the retrieval strategies disruption hypothesis (Basden et al., J Exp Psychol Learn Memory Cogn 23(5):1176-1191, 1997). In two experiments, we further examined this hypothesis by testing whether the memory task (free recall vs. serial recall) and the recall method (turn-taking vs. unconstraint) moderate collaborative inhibition. Experiment 1 compared the performance of collaborative and nominal groups in a free recall and a serial recall task. Results revealed collaborative inhibition in free recall, but this effect was reduced in serial recall. In Experiment 2, collaborative and nominal performance was compared in the same tasks with collaborative but also nominal groups, using the turn-taking method. The collaborative inhibition effect was still observed in free recall, although to a lesser extent when participants in nominal groups used the turn-taking method. In the serial recall task, the collaborative inhibition effect was eliminated. Taken together, these results further support retrieval strategies disruption as an explanation for the collaborative inhibition effect.