Social anxiety, acute social stress, and reward parameters interact to predict risky decision-making among adolescents

• We tested effects of social anxiety, social stress and rewards on risk-taking.
• Reward value influenced risk-taking in those with high but not low social-anxiety.
• Social stress affected reaction time in those with low but not high social-anxiety.
• Those with high social anxiety evidenced greatest RT on the most negative trials.
• Effects of context and reward parameters depended on level of trait social anxiety.

Risk-taking behavior increases during adolescence, leading to potentially disastrous consequences. Social anxiety emerges in adolescence and may compound risk-taking propensity, particularly during stress and when reward potential is high. However, the manner in which social anxiety, stress, and reward parameters interact to impact adolescent risk-taking is unclear. To clarify this question, a community sample of 35 adolescents (15–18 yo), characterized as having high or low social anxiety, participated in a study over two separate days, during each of which they were exposed to either a social stress or a control condition, while performing a risky decision-making task. The task manipulated, orthogonally, reward magnitude and probability across trials. Three findings emerged. First, reward magnitude had a greater impact on the rate of risky decisions in high social anxiety (HSA) than low social anxiety (LSA) adolescents. Second, reaction times (RTs) were similar during the social stress and the control conditions for the HSA group, whereas the LSA group's RTs differed between conditions. Third, HSA adolescents showed the longest RTs on the most negative trials. These findings suggest that risk-taking in adolescents is modulated by context and reward parameters differentially as a function of social anxiety.