Collective and individual processes in remembering

When a group of people work together to remember an event, the group do appear to recall more than an individual working alone, but do they recall more than the sum of the memories each individual recalls?

Studies have found that "brainstorming" groups actually produce fewer ideas than groups that are groups in name only1. And in many tasks, from rope-pulling to vigilance tasks, it has been found that people contribute less when they are part of a group than when they are working alone2.

In this study, two experiments compared the memory performance of nominal and collaborative groups of three, using

  • random lists of pictures and words;
  • a story (The "War of Ghosts", a supposed folk-tale, long used in psychology labs to demonstrate the errors in people's memories)

It was found that the nominal groups (where individual results were pooled) remembered the best. Collaboration appears to inhibit recall. Such collaborative inhibition was greater with the story than with the list.


1. Bouchard, T. J. Jr. & Hare, M. 1970. Size, performance, and potential in brainstorming groups. Journal of Applied Psychology, 54, 51-55.

Diehl, M. & Stroebe, W. 1987. Productivity loss in brainstorming groups: Toward solution of a riddle. Journal of Personality and Social Psychology, 53, 487-509.
Dunnette, M. D., Campbell, J. & Jaastad, K. 1963. The effects of group participation on brainstorming effectiveness for two industrial samples. Journal of Applied Psychology, 47, 30-37.

2. Karau, S.J. & Williams, K.D. 1993. Social loafing: A meta-analytic review and theoretical integration. Journal of Personality and Social Psychology, 65, 681-706.

  • "Brainstorming" actually produces fewer ideas than would be produced by the same individuals working individually
  • Groups working together to remember something recall more poorly than the same individuals would working on their own
  • The inhibitory effect of working in a group is worse when the information being recalled is more complex

Weldon, M.S. & Bellinger, K.D. (1997). Collective and individual processes in remembering. Journal of Experimental Psychology: Learning, Memory and Cognition, 23, 1160-1175.