Myriad psychological research evinces a negative association between self-control and aggression with some arguing for self-control failure as a cause of aggression. Recent literature suggests that the relationship between aggression and self-control is likely more complex and even positive in some cases. One source of such conflict in the literature could be the presence of unaccounted for random item slopes in commonly used measures of self-control which may inflate the likelihood of Type I errors. This study (N = 1386) tested the hypothesis that self-control would share random item slopes with the facets of trait aggression using random item slope regression.