Abstract

A study investigated how the ability to suppress thoughts in the laboratory was affected by type of thought suppressed (positive, negative, neutral), participants’ age and working memory capacity (WMC). Linked variables (Use of thought suppression, social desirability, and mindfulness) were measured to assess whether they modified susceptibility to thought intrusion. Younger, middle aged and older adults suppressed three different valenced thoughts in a counterbalanced order for 5-min per thought. Participants then completed a WMC task and questionnaire measures of the linked variables. Valence had no effect on intrusions. WMC was positively related to intrusions; higher WMC corresponded to greater intrusions. Age was negatively related to intrusions; with increasing age intrusions decreased. Hierarchical regression showed only age and backward digit span (WMC) significantly predicted intrusions. The relationship between WMC and intrusions was not moderated by age. WMC and age both independently predict level of intrusion, and no synergistic effect was found.