The Effect of Expert Testimony on Jury Perception of Battered Woman Syndrome: An Experimental Evaluation of Counterfactual Reasoning and Blame Attribution

This experimental study evaluated the influence of Battered Woman Syndrome (BWS) expert testimony on mock juror decision-making, focusing on counterfactual reasoning, blame attribution, and final verdict outcomes. A sample of 256 jury-eligible adults was randomly assigned to a 2 (Expert Testimony: Present vs. Absent) × 2 (Abuse Severity: High vs. Moderate) between-subjects factorial design based on a trial vignette involving a female defendant accused of killing her abusive partner during a non-confrontational lull in violence. Results revealed that the presence of BWS expert testimony significantly reduced the generation of victim-focused counterfactual thoughts (e.g., "If only she had left the relationship") and substantially decreased victim blame attribution. Furthermore, mediation analysis demonstrated that victim-focused counterfactual thinking served as a significant indirect mechanism through which expert testimony reduced guilty verdicts and increased self-defense acquittals. Abuse severity moderated these effects, with expert testimony exerting its strongest protective impact under moderate abuse conditions where juror skepticism was naturally higher. These findings demonstrate that forensic psychological expert testimony functions primarily by altering cognitive counterfactual framing, helping jurors contextualize non-confrontational self-defense and mitigate pervasive hindsight biases in intimate partner violence cases.