Pavlíčková, K., Gärtner, J., et al. (2024).
Communications Psychology, 2(1).
Abstract
Although the acute stress response is a highly adaptive survival mechanism, much remains unknown about how its activation impacts our decisions and actions. Based on its resource-mobilizing function, here we hypothesize that this intricate psychophysiological process may increase the willingness (motivation) to engage in effortful, energy-consuming, actions. Across two experiments (n = 80, n = 84), participants exposed to a validated stress-induction protocol, compared to a no-stress control condition, exhibited an increased willingness to exert physical effort (grip force) in the service of avoiding the possibility of experiencing aversive electrical stimulation (threat-of-shock), but not for the acquisition of rewards (money). Use of computational cognitive models linked this observation to subjective value computations that prioritize safety over the minimization of effort expenditure; especially when facing unlikely threats that can only be neutralized via high levels of grip force. Taken together, these results suggest that activation of the acute stress response can selectively alter the willingness to exert effort for safety-related goals. These findings are relevant for understanding how, under stress, we become motivated to engage in effortful actions aimed at avoiding aversive outcomes.
Here are some thoughts:
This study demonstrates that acute stress increases the willingness to exert physical effort specifically to avoid threats, but not to obtain rewards. Computational modeling revealed that stress altered subjective value calculations, prioritizing safety over effort conservation. However, in a separate reward-based task, stress did not increase effort for monetary gains, indicating the effect is specific to threat avoidance.
In psychotherapy, these findings help explain why individuals under stress may engage in excessive avoidance behaviors—such as compulsions or withdrawal—even when costly, because stress amplifies the perceived need for safety. This insight supports therapies like exposure treatment, which recalibrate maladaptive threat-effort evaluations by demonstrating that safety can be maintained without high effort.
The key takeaway is: acute stress does not impair motivation broadly—it selectively enhances motivation to avoid harm, reshaping decisions to prioritize safety over energy conservation. The moral is that under stress, people become willing to pay a high physical and psychological price to avoid even small threats, a bias that is central to anxiety and trauma-related disorders.
