Study Reveals Stress May Make Us More Altruistic in the Face of Injustice

A study reveals that stress experienced while witnessing injustice may bias the brain toward altruistic behaviors, such as helping victims over punishing offenders. The research, involving fMRI scans of participants in a decision-making task under stress, shows a shift in brain activity that favors altruistic choices, highlighting the complex influence of stress on moral decisions.

During a brain scan, while engaging in a bystander intervention task, participants experiencing stress displayed distinct neural activation patterns compared to those who were not stressed, and were more likely to help the victim.

According to a study recently published in the journal PLOS Biology, experiencing stress while observing injustice might incline your brain toward altruism. This research was conducted by Huagen Wang and colleagues at Beijing Normal University, China.

It takes more cognitive effort to punish others than it does to help them. Studies show that when witnessing an act of injustice while stressed, people tend to behave selflessly, preferring to help the victim rather than punish the offender. This aligns with theories proposing that distinct brain networks drive intuitive, fast decisions and deliberate, slow decisions, but precisely how a bystander’s brain makes the trade-off between helping and punishing others in stressful situations is unclear.

The Study’s Design and Findings

To better understand the neural processes driving third-party intervention in the face of injustice, Wang and colleagues recruited 52 participants to complete a simulated third-party intervention task in an fMRI (functional magnetic resonance imaging) scanner, where they watched someone decide how to distribute an endowment of cash between themself and another character, who had to passively accept the proposal.

The participant then decided whether to take money away from the first character, or give money to the second. Roughly half of these participants submerged their hands in ice water for three minutes right before starting the task to induce stress.

Acute stress decreased the third party’s willingness to punish the violator and the severity of the punishment, and increased their willingness to help the victim. Credit: Huagen Wang (CC-BY 4.0)

Acute stress affected decision-making in extremely unfair situations, where the participant witnessed someone keep the vast majority of the cash they were supposed to split with someone else. The researchers observed higher dorsolateral prefrontal cortex (DLPFC) activation—a brain region typically linked to mentalizing and decision-making—when stressed participants chose to punish an offender. Computational modeling revealed that acute stress reduces bias towards punishment, raising the likelihood that someone will help a victim instead.

The researchers state that their findings indicate that punishing others requires more deliberation, cognitive control, and reliance on calculations than helping a victim. These results align with a growing body of evidence suggesting that stressed individuals tend to act more cooperatively and generously, perhaps because people devote more of their cognitive resources towards deciding how to help the victim, rather than punishing the offender.

The authors add, “Acute stress shifts third-party intervention from punishing the perpetrator to helping the victim.”

Reference: “Acute stress during witnessing injustice shifts third-party interventions from punishing the perpetrator to helping the victim” by Huagen Wang, Xiaoyan Wu, Jiahua Xu, Ruida Zhu, Sihui Zhang, Zhenhua Xu, Xiaoqin Mai, Shaozheng Qin and Chao Liu, 16 May 2024, PLOS Biology.
DOI: 10.1371/journal.pbio.3002195

The research was supported by the National Natural Science Foundation of China, the Major Project of National Social Science Foundation, and the Beijing Municipal Science and Technology Commission.