Online Intervention Reduces Hostile Attribution Bias, Anger, Aggressive Driving, and Cyber-Aggression, Results of Two Randomized Trials

Background Anger and aggression often result from attributing hostile intent to the ambiguous actions of other people. Methods Two online double-blind parallel randomized pilot studies with healthy adult volunteers tested a novel online cognitive intervention called Hostile Bias Modification Training (HBMT). We hypothesized HBMT would reduce hostile attribution bias, anger, and aggression. In study one, 180 volunteers were randomized to one of three versions of HBMT (active, alternative, and placebo). In study two, 217 volunteers were randomized to either active or placebo HBMT and returned 24–96 h later to complete measures of hostile attribution bias, anger, and aggression. Results In study one, volunteers who completed active HBMT (vs. placebo) subsequently interpreted hypothetical vignettes as significantly less hostile ( d = 0.64, p = .006) and reported significantly less imagined anger ( d = 0.51, p = .006) and aggression ( d = 0.73, p < .001). In study two, active HBMT (vs. placebo) was associated with reduced hostile attribution bias ( _p^2 = .089, p < .001), less aggressive driving ( _p^2 = .039, p = .027), and lower likelihood of cyber-aggression (OR 0.56, p = .004) 24–96 h after intervention. Conclusions These results suggest HBMT may be an easily implemented intervention to improve anger-related outcomes. No harms to volunteers were observed. This trial was registered at ClinicalTrials.gov: NCT04015440 on July 11 2019.