Psychologists have found that individual recall is better than collaborative recall in typical word list recall tasks (e.g. Finlay, et.al., 2000). That is, if experimenters give participants a list of unconnected words to learn, they remember more of them if they work alone, than if paired into a group. Individuals rarely spontaneously introduce false positives when completing lists alone.
However, real life does not merely involve brute rote memory, it requires narrative construction. Real mnemic epistemic success requires the ability to both remember facts and avoid false memories. Consider a significant event, such as a marriage. When recollecting details it can be difficult to avoid adding embellishments (e.g. was it really a mustard sauce or did the steak have a pepper sauce?). However, if we convey memories with fellow event attendees, then narrative flourishes or mistakes can be picked up on and removed (or scaled back) to maintain group accuracy, (e.g. it was definitely pepper because Bob says he bit on a peppercorn and started sneezing).
There is a new social false memory task which is being used to investigate collaborative reduction of false memories.
The most widely used false memory paradigm is the DRM word list (Roediger & McDermott, 1995) In this task, normal subjects are presented with lists of words with similar semantic associates (e.g. mad, fear, hate, rage, temper, fury) of a particular prototype word (e.g. anger), which is not itself studied. In subsequent tests, subjects are given lists of words that included the original list, the prototype word and unrelated words (e.g. bread). Although participants are able to separate out the semantically irrelevant words (e.g. bread), they were just as likely to recall prototype words as the actual words from the list (e.g. they claim that 'anger' was part of the original list). Not only this, but they claim to vividly recollect seeing 'anger'.
A newer false memory paradigm tests the effect of social factors in false memory creation (Roediger et.al., 2001):
Participants briefly viewed pictures of six rooms in a house and subsequently tried to recall the objects in each room... Immediately after viewing the pictures, participants were asked to remember six items from each scene. Participants took turns doing the recall with an anonymous 'other participant' who also recalled six items from the scene. The 'other participant' was actually a computer programmed to provide responses from a list of items in the photos. For three of the scenes, the computer provided the names of two items that had not appeared... Some of these false items would seem very likely to be in the target scene (high-expectancy items); other false items were less likely to be in the target scene (low-expectancy items), though not out of place...The critical recall phase occurred next. Participants were asked to remember as many items from each scene as they could. (Ross, et. al., p.86)Collaboration on this task reduces false memory errors in both older and younger subjects (Ross et.al, 2004).
False memory experiments are an institutional type of gaslighting, deliberately tricking or manipulating other's beliefs. They provide an excellent opportunity to study how social settings can yield skewed beliefs. I'd like to do the above experiment with different power structures. For example, instead of a computer program suggesting false items, a high-status individual would suggest them. I expect that false memory acceptance would increase when a powerful person suggests them and little external verification available.
 We might say that pepper sauce is the least important feature of a wedding to remember, however, those sort of facts are precisely what psychologists tend to examine in word list tasks.
Finlay, F., Hitch, G.J., & Meudell, P.R. (2000). Mutual inhibition in collaborative recall: Evidence for a retrieval-based account. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 1556-1567.
Roediger, H.L., III, McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, and Cognition, Vol. 21, 803-814.
Roediger, H. L., III. Meade, M. L., & Bergman, E. T. (2001). Social contagion of memory. Psychonomic Bulletin & Review, 8, 365-371
Ross, M., Spencer, S.J., Lindardatos, L., Lam, K.C.H., & Perunovic, M. (2004). Going Shopping and identifying landmarks: Does collaboration improve older people’s memory? Applied Cognitive Psychology, 18, 683-696.