While suppression is associated with detrimental post-traumatic psychological adjustment, research has not considered the effect of culture on this relationship.

This study investigated cultural differences in the effects of expressive suppression, whilst watching a traumatic film, on subjective distress, psychophysiological responses and intrusive memory.

Australians of European heritage or East Asian Australian participants (n = 82) were randomly assigned to either a suppression group (instructed to suppress their emotions during the film) or a control group (no instructions regarding emotion management). Electrodermal activity, heart rate and heart rate variability (root mean square of the successive differences; RMSSD) were measured pre-, during and post-film. Participants reported the number of film-related intrusions in the 5 min and 7 days post-viewing.

While the European Australian group did not differ significantly on RMSSD, the East Asian suppression group scored significantly higher on RMSSD during the film than the East Asian control group. Second, those in the suppression groups, regardless of cultural background, reported significantly fewer intrusions immediately post-film than controls. Third, we found that for the European Australian group, change in heart rate interacted with group (control versus suppression) when predicting weekly intrusions. However, for the East Asian group change in heart rate did not interact with group when predicting weekly intrusions.

The findings are discussed in the context of current research on culture and emotion regulation and implications for post-traumatic stress disorder.