Original:  In this view, repressors try to suppress thoughts of their undesirable traits , and these efforts make those trait categories highly accessibleso that they are then used all the more often when forming impressions of others.
Revised:  In this view, repressors try to suppress thoughts of their undesirable traits make those trait categories highly accessibleso that they are then used all the more often when forming impressions of others.
Edit intent: clarity