When Helping is Risky: The Behavioral and Neurobiological Tradeoff of Social and Risk Preferences

Helping others can entail risks for the helper. For example, when treating infectious patients, medical volunteers risk their own health. In such situations, helping-decisions should depend on the individual’s valuation of others’ well-being (social preferences) and the degree of personal risk the individual finds acceptable (risk preferences). We investigate how these distinct preferences are psychologically and neurobiologically integrated when helping is risky. We used incentivized decision-making tasks (Study 1, N=292, mean age=22.3±3.7, 142 female) and manipulated dopamine and norepinephrine levels in the brain by administering methylphenidate, atomoxetine, or placebo (Study 2, N=154, mean age=23.7±3.9, 77 female). We find that social and risk preferences are independent drivers of risky helping. Methylphenidate increased risky helping by selectively altering risk- rather than social preferences. Atomoxetine influenced neither risk nor social preferences and did not affect risky helping. This suggests that methylphenidate-altered dopamine concentrations affect helping decisions that entail a risk to the helper.