Several studies found that acute stress leads to increased risk taking in humans. However, this effect appears to be time-dependent because the few studies that examined delayed (>40 min after stress onset) stress effects show in fact a decrease in risk taking. In 32 young healthy women, we intra-individually examined whether psychosocial stress decreases risk taking 80 min after stress induction. All participants performed the Balloon Analog Risk Task (BART) twice: once after exposure to the Trier social stress test (TSST) and once after a control condition Placebo-TSST (P-TSST). The experimental order was randomized across participants. The psychophysiological stress response increased after the TSST compared to the P-TSST, indicated by elevated cortisol concentrations, elevated alpha-amylase activity, and elevated blood pressure. We found a significant interaction of stress condition and experimental order. Compared to the control condition psychosocial stress decreased risk taking in novel decision situations but not when participants were already familiar with the BART from the prior condition. Delayed effects of psychosocial stress lead to a decrease in risk taking in unfamiliar but not familiar conditions 80 min after stress exposure. Lay summary It has been suggested that stress exerts delayed effects on risk taking propensity. We found that individuals who are exposed to psychosocial stress take less risk when confronted with novel decisions even 80 min after the stressor compared to individuals who are not stressed.
Keywords: Stress; TSST; alpha-amylase; cortisol; decision making; risk taking.