The Effect of Item Similarity and Response Competition Manipulations on Collaborative Inhibition in Group Recall

Collaborative inhibition refers to when people working together remember less than their predicted potential. The most common explanation for this effect is the retrieval-disruption hypothesis during collaborative recall. However, several recent studies have obtained conflicting results concerning this hypothesis. In the current study, item similarity was manipulated in Experiment 1 by requiring participants to study overlapping or non-overlapping unrelated wordlists. The unstructured instructions were then manipulated during a turn-taking recall task between conditions. The results showed that collaborative inhibition occurred for both overlapping and non-overlapping conditions. Subsequently, response competition during collaborative recall, in addition to item similarity, was manipulated in Experiment 2, and the results showed that when collaborative group members were instructed to recall in turn and monitor their partner's recall (the medium- and high-response-competition conditions), collaborative inhibition occurred. However, no such effect was shown when collaborative group members were instructed not to communicate with each other, but to simply recall in turn while in a group (low-response-competition condition). Together, these results suggest that the conflicts between the findings of the aforementioned studies were probably caused by differing instructions, which induced response competition in collaborative settings. Aside from retrieval-disruption, other possible mechanisms underlying collaborative inhibition were also discussed.