False denials increase false memories for trauma-related discussions.

False denials are sometimes used to cope with traumatic experiences. We examined whether false denials can affect true and false memory production for a traumatic event and conversations surrounding the trauma. One hundred and twenty-six participants watched a trauma analogue video of a car crash before being randomly asked in a discussion with the experimenter to (1) respond honestly or (2) falsely deny that certain details happened in the video. After one week, all participants received misinformation about the discussion with the experimenter and the car crash. Finally, all participants were instructed to respond truthfully in a source memory task. Participants who falsely denied information during the first session were statistically significantly more prone than honest participants to omit details they denied and to report misinformation about what was discussed in the first session. Our work suggests that false denials of a traumatic experience might lead to both forgetting and increased false memory levels for earlier conversations about the event.