Acute stress reduces effortful prosocial behaviour

Abstract

Acute stress can change our cognition and emotions, but what specific consequences this has for prosocial behaviour is unclear. Previous studies have mainly investigated prosociality with financial transfers in economic games and produced conflicting results. We examined how acute stress changes our willingness to exert effort for others, which is a core feature of many types of real-life prosocial behaviour. Participants – half of whom were put under acute stress – made decisions whether to exert physical effort to gain money for themselves or another person. With this design, we could independently assess the effects of acute stress on prosocial, compared to self-benefitting, effortful behaviour. Compared to controls, stressed participants chose to exert effort more often for self- than for other-benefitting rewards. This was particularly pronounced for more selfish participants. Neuroimaging combined with computational modelling revealed a putative neural mechanism underlying these effects: more stressed participants showed increased activation to subjective value in the dorsal anterior cingulate cortex (dACC) and anterior insula when they themselves could benefit from their exerted effort relative to when someone else could. Activation differences in the dACC mediated the effect of perceived stress on effortful prosocial behaviour. Using effort-based paradigms to better approximate real-life prosocial behaviour and incorporating trait differences in prosocial tendencies could be key to understanding how acute stress affects prosociality. Considering the importance of such behaviours for our individual relationships and social cohesion, this highlights the need to tackle the sources of stress and help people better cope with stress when it occurs.

The Drive to Survive: Acute Stress Promotes Aversive Motivation

“…For example, stressed participants have been reported to exhibit a reduced willingness to exert cognitive effort, such as engaging in a challenging demand selection task 13 . On the other hand, we have previously observed a reduced emphasis on learning to minimize physical effort under stress (thus facilitating effort expenditure), while Forbes et al 14 reported a reduction in the willingness to exert physical effort only for the financial benefit of others. In contrast, the study by Forbes et al 14 found no evidence for a stress-induced change in the willingness to exert physical effort for personal rewards, aligning with Experiment 2 results.…”

“…On the other hand, we have previously observed a reduced emphasis on learning to minimize physical effort under stress (thus facilitating effort expenditure), while Forbes et al 14 reported a reduction in the willingness to exert physical effort only for the financial benefit of others. In contrast, the study by Forbes et al 14 found no evidence for a stress-induced change in the willingness to exert physical effort for personal rewards, aligning with Experiment 2 results. Collectively, these emerging results reveal how stress can induce situationallyspecific effects on motivation, which is relevant for psychopathology related to anxiety and/or avoidance, reward-seeking behavior, and social interactions.…”

“…Results from Experiment 2, as well as a limited amount of available previous work, suggest that the acute stress response does not promote a universal increase in the willingness to exert effort 12,13,14 . For example, stressed participants have been reported to exhibit a reduced willingness to exert cognitive effort, such as engaging in a challenging demand selection task 13 .…”

“…All participants were informed to not consume any caffeine or food (<2 hours before session), alcohol (day of session), or painkillers (day of session), which was confirmed verbally before the start of the study session. Eight participants were excluded or data were unavailable because of early termination of the experiment (n=2; one at the start of the session and one at the start of stress-induction procedures), failure to adhere to study guidelines (n=1; consumption of coffee and painkillers), a hardware issue (n=1; data not saved), BMI (n=1; BMI ~15), and "inflexible responder" status 14,30,31 (i.e., no variation in choices for all effort-threat combinations; 2 MASTPLC, 1 MASTEXP), although their inclusion did not change any key results (see below).…”

The acute effects of stress on dishonesty are moderated by individual differences in moral default

“…Accounting for these individual differences may help resolve the controversy on the effect of stress on prosocial decision making. In line with this reasoning, a recent study by Forbes and colleagues 29 found that individuals with a more selfish social value orientation exhibit even more selfish behavior under acute stress, whereas this was not observed for individuals with a more prosocial value orientation. Moreover, Azulay and colleagues 30 reported that individuals with high trait empathy became more prosocial after acute stress, whereas individuals with low trait empathy became more selfish.…”