Collaborative false recall in the DRM procedure: Effects of group size and group pressure

Basden, Basden, Thomas, and Souphasith (1998) demonstrated that false recall in collaborative trios is enhanced when group members feel under pressure to output items. In the present study, individuals, pairs, trios, and quartets were presented with lists of words drawn from the Deese-Roediger-McDermott paradigm. Memory was tested under high or low group pressure conditions. It was found that false recall increased in proportion to group size regardless of group pressure, but that groups experiencing the most pressure to output items made a greater number of errors. Furthermore, on a surprise later individual recall test, participants who experienced the most pressure during collaboration retained an equivalent level of critical lures. Collectively these findings demonstrate that group pressure can increase collaborative false recall, and that these false memories can be retained beyond group testing.