Cultures can be (very roughly) described as independent or interdependent. Many western cultures (eg the US, UK, Australia, New Zealand and Canada) are generally independent – they value separateness, autonomy and self-sufficiency and consider the individual to be at least as important as the group. Many eastern cultures (eg China, Japan, and parts of the m\Middle East) tend to be interdependent – they emphasize connectedness, social context and harmony and value the group more highly than any individual in it.
When a group of eyewitnesses get together to talk about an event, it is almost inevitable that there will be times when two people will have conflicting memories of the same aspect of the event. Groups from independent cultures tend to have a relatively low tolerance for this situation (often termed incongruity/cognitive dissonance in the psychological literature) and are likely to want to work out which of the two people is right. They will employ a range of strategies to determine this including taking a vote to see which version the majority of the group agrees with. Indeed, it’s quite likely that the second person will begin his or her version with the words “No, you’re wrong – it was like this.” While we in the west regard it as a bit awkward if this causes a robust discussion in which both sides insist that their version is the correct one, we are much more interested in finding out “what really happened” than in group harmony, so if the group splits into two camps and members of the other side don’t actually talk to us again, we see that as their problem not ours.
Groups from interdependent cultures will try to maintain harmony within the group, so they will work towards a compromise, even if the compromise position cannot possibly be the truth because no-one (initially) remembers it happening in that way. They often have a higher tolerance for incongruity/cognitive dissonance – and the fact that the early church was quite happy to accept the four gospels as canon suggests that they were like this. Tatian was possibly an exception, although the Diatessaron may simply have been a different way of allowing all versions of the Jesus story to be heard. I am not sure how long ago parts of western Christianity started to try to explain how there really is no contradiction between the gospels, but it does not appear to have been an issue for the church of the fourth century. (References for the effect of culture on dealing with differences in memory of events include: Jennifer L. Aaker and Jaideep Sengupta, “Additivity versus Attenuation: The Role of Culture in the Resolution of Information Incongruity,” Journal of Consumer Psychology 9 (2000): 67–82; Jennifer L. Aaker, “Accessibility or Diagnosticity? Disentangling the Influence of Culture on Persuasion Processes and Attitudes,” Journal of Consumer Research 26 (2000): 340; Sheena S. Iyengar and Mark R. Lepper, “Rethinking the Value of Choice: A Cultural Perspective on Intrinsic Motivation,” Journal of Personality and Social Psychology 76 (1999): 349–66; Michael W. Morris and Kaiping Peng, “Culture and Cause: American and Chinese Attributions for Social and Physical Events,” Journal of Personality and Social Psychology 67 (1994): 949–71.)
The other thing that has a significant effect on both recall and group processes is the relative authority of the people involved. There is significant evidence that the perceived authority of the person asking questions about an event will have an effect on how eyewitnesses answer questions. I am very frustrated that I can’t find the relevant references for this, but in general if someone with higher authority asks the questions, people will try harder to remember things and be more inclined to guess. Over time, the guessing is remembered more and more confidently (see, for example Hastie, Reid, Robert Landsman, and Elizabeth F Loftus. “Eyewitness Testimony: The Dangers of Guessing.” Jurimetrics Journal 19, no. 1 (1978): 1-8 and Schacter, Daniel L. The Seven Sins of Memory: How the Mind Forgets and Remembers. Boston: Houghton Mifflin, 2001: 115-117). And, although I don’t have references to back this up, I also suspect that the perceived relative authority of group members will affect how much notice is taken of their accounts of events. In strongly hierarchical societies, I suspect that it it both more likely that the more senior members of the group are given the opportunity to speak first and that there is significant unease about saying something that would make these people look as though they had made a mistake. This is certainly the case with the international students that I work with, and makes it challenging for them to operate in tutorial groups where they find it very difficult to question anything said by the lecturer or tutor.
Since it is well documented that ageing tends to have a negative effect on the memory and age is one of the criteria for authority and respect in eastern cultures, we have the possibility that the most flawed memory of the story is the one that the group accepts as accurate or is the most influential in forming the version that the group accepts and passes on. Given that there were quite a few eyewitnesses to many of the events in Jesus’ public ministry, it is highly likely that a range of different “agreed versions” of what he said and did were in circulation fairly soon after each event as different small groups talked together about their experiences.
A couple of references about the effect of the authority or credibility of the questioner are James Marshall, Law and Psychology in Conflict (Indianapolis: Bobbs-Merrill, 1965), 41–63; Loftus, Eyewitness Testimony, 98; Gerald Echterhoff, William Hirst, and Walter Hussy, “How Eyewitnesses Resist Misinformation: Social Postwarnings and the Monitoring of Memory Characteristics,” Memory & Cognition 33 (2005): 770–82.