People who feel less pain are also less willing to help others

A reduced ability to feel pain in one's own body leads to a reduced willingness to help others who feel pain. This result of a study published in Psychological Science by cognitive psychologists at the University of Vienna led by Claus Lamm and Helena Hartmann points beyond the individual effects of pain medication to its social costs.

It has been known for a few years that there is a connection between the ability to feel pain in one's own body and empathy for the pain of other people. This conclusion was reached in multiple experiments in which subjects were given placebo painkillers (i.e., pills without a pharmacological agent), which affected both their emotions and corresponding brain activity. It is also known that people‘s ability to empathize is related to how helpful they are. However, no research has yet been done to determine whether reducing one's sensitivity to pain actually leads to a lower willingness to help.

Social neuroscientist Helena Hartmann and her three co-authors from the University of Vienna have now published the results of an experimental study that investigated this question in the journal Psychological Science. 90 participants were confronted with a situation in which they believed another person was being administered varying amounts of painful electrical stimuli. However, the participants had the opportunity to reduce the supposed amount of these stimulations by exerting physical effort – squeezing a hand dynamometer measuring their force. Before they made their choices, however, half of the participants received a supposed painkiller – a so-called deceptive placebo – while the other half did not. In fact, the belief that one has taken a pain-reducing medication already measurably reduces one's own sensitivity to pain. Indeed, the experiment showed that the group that had received the placebo painkiller was less often willing to reduce the number of electric shocks through own physical effort than the group that did not receive placebos. However, this was only the case if there was little one could do to help the other person, e.g., reduce the stimuli by one. And even when individuals chose to help the other person, the placebo group pushed the dynamometer less than the control group. Importantly and interestingly, this effect was dependent on how much empathy the participant felt for the second participant receiving the stimuli. The placebo painkiller dampened the participants‘ empathy, which in turn led to reduced helping behavior.

"Previous studies had already shown that such a placebo can reduce empathy. Our experiment now shows for the first time that it also reduces the willingness to engage in actual helping behavior, based on this reduced empathy," Hartmann explains. The study hints that already one-dose painkillers can have subtle effects on our behavior toward others. Such effects could have far-reaching consequences for people with chronic pain conditions, but also for people who are under the (regular) influence of painkillers. "If this is confirmed for actual pain medication and in studies outside the laboratory, this negative social side effect would have to be publicized," adds group leader and co-author Claus Lamm. After all, the social consequences of this study go beyond the use of painkillers: the willingness to help others who are in distress is the basis of social cohesion and has a significant influence on one's own social well-being.

Publication in Psychological Science: 

Helena Hartmann, Paul Forbes, Markus Rütgen, & Claus Lamm: Placebo analgesia reduces costly prosocial helping to lower another’s pain. In: Psychological Science, 2022. 

DOI: 10.1177/09567976221119727