Study finds that small amounts of stress increase empathy levels

Elevated levels of stress have long been associated with the fight-or-flight response, an instinctive physiological response exhibited by animals in harrowing situations. Although being stressed appears detrimental, small amounts of stress can lead to increased levels of empathy and other prosocial behavior, according to a study published in the journal Social Cognitive and Affective Neuroscience in March.

An international team of researchers, which included leader Claus Lamm of the University of Vienna, utilized stress tests on neural mechanisms in combination with fMRIs in order to assess exactly how stress affects the brain’s neural empathy network.

Since previous studies hypothesized that a link between stress and increased empathy existed solely in females, this study looked to solidify evidence of the same link in males. Study participants included 76 healthy men between the ages of 18 and 40, with each participant completing screening questionnaires prior to the experiment that gauged their mental and physical health. Those who reported prescription medication use, psychiatric illness, psychoactive drug or alcohol use, social anxiety or smoking on a daily basis were excluded from the study.

Participants prepared for the study by abstaining from drug and medication use for 24 hours prior to the experiment. Researchers assessed their baseline cortisol levels before receiving instructions related to experimental tasks and being placed in the fMRI scanner. Participants first received an anatomical scan and preparation paradigm, followed by the stress paradigm, which was either stress or control version of the Montreal Imaging Stress Task. MIST includes several computerized mental arithmetic challenges and evaluative threat components that are administered by researchers or a computer program.

While participants under the stress paradigm completed the MIST in the fMRI scanner, the potential for their stress levels to rise was further increased by being timed and shown a live webcam broadcast of a researcher allegedly watching them and taking notes. In the control version of the experiment, participants solved similar arithmetic problems as the other group, but without any sort of recording of their performance, researcher observation or time restriction.

Throughout the entirety of the experiment, saliva samples were collected from all participants. After being scanned, the stress levels of the participants were calculated by assessing these samples for cortisol levels.

Subsequent parts of the study consisted of participants viewing 36 photographs of painful or uncomfortable medical procedures, such as a hand receiving a needle injection on a green surgical sheet. During this part of the experiment, participants were instructed to imagine the sort of pain that a patient receiving the procedure might be experiencing. For several photographs, participants were told that the patient had been under anesthesia at the time of the procedure. This allowed the researchers to measure the ability of participants to regulate their own emotions, as well as take the patient’s perspective, aka empathy.

Researchers found that the neural reactions of participants were just as strong when they knew that the patient’s procedure was not actually a painful one.

“Based on their neural responses, stressed participants had a stronger emotional reaction to the pictures. However, this implies that they also ignored complex information about the actual situation the shown person was in,” said Lamm.

In another portion of the experiment, researchers analyzed the prosocial behavior of participants by way of a behavioral economics game known as the dictator game. In the activity, participants were given 10 euros and told that they could give a portion of the money in any ratio they desired with an anonymous participant of the experiment. The participants were also told that they would be able to keep the money that they had decided to allot to themselves, along with the money that the previous participant had allotted to them. However, participants were not told how much money had been given to them by the previous participant until the conclusion of the experiment.

Researchers determined that participants’ neural activity during the procedure experiment was correlated to the prosocial behavior exhibited during the dictator game. The stronger the participant’s brain reacted to the pain of the patient, the more money the participant shared with the anonymous participant.

“In some circumstances, the stronger emotional response might thus result in aid that is uncalled for or inappropriate, for example when one’s first impression of another’s mental state does not match their actual emotion—e.g. when someone is crying out of joy,” said Lamm. “Hence, depending on the context and situation, stress can be either beneficial or detrimental in social situations.”