Eyewitness reports become less accurate after exposure to inconsistent information. When such phenomenon of diminishing accuracy occurs among cowitnesses, it is termed memory conformity or the social contagion effect. The present study set out to provide a rigorous test of the underlying mechanisms with particular emphasis on investigating whether genuine false memory is involved. To this end, we conducted an earwitness experiment in which some participants were exposed to discrepant cowitness information and provided their recollections repeatedly and under different conditions. Additionally, we examined the impact of cowitness intimacy by using a random assignment procedure, an aspect that has not been previously studied. With regard to the underlying processes, our findings clearly argue that informational rather than normative influence plays a dominant role. Moreover, highly accurate source attributions indicated that participants were aware of drawing on the recollection of their counterparts. Consequently, we did not obtain any evidence for false memory. With regard to cowitness intimacy, the results were inconsistent and call for further research.