Alcohol use disorder (AUD) is associated with deficits in social cognition, but the relationship between harmful alcohol use and the processes underlying interactive social behavior is still unknown. We hypothesized that prosocial decision-making is reduced in AUD and that individual differences in the underlying processes are key to better understand these reductions.
In one laboratory study (Swedish participants, n=240) and one confirmatory online study (American participants, n=260), we compared young adults with AUD to age-, gender-, and education-matched healthy controls on six facets of prosocial decision-making. We used standardized behavioral economic tasks, namely: Dictator Game, Ultimatum Game, Trust Game, and Third-Party Game. To better understand the expected differences in prosociality, we evaluated attention by tracking eye-gaze, decision response time, clinical symptoms and social cognition.
Altruism (Lab study: p = .007; Online study: p < .001), Fairness (Lab study: p = .003; Online study: p = .007), and Reciprocal trust decisions (Lab study: p = .007; Online study: p = .039) were reduced in AUD compared to healthy controls whereas Trust, and Third-party punishment and compensation were comparable in both studies. Reduced prosociality was associated with attending to the selfish response option, faster response time, and moral attitudes, while dissociated from both psychiatric symptoms and drinking history in AUD.
Individuals with AUD have trait-related reductions in prosocial decision-making that do not vary with drinking history or psychiatric symptom load. These reductions were confined to one-to-one interaction accompanied by differences in attention, decision-time and moral attitudes.