The study was about pain. Not, “Ouch, I stubbed my toe!” pain, but rather “that wasn’t a very nice thing to say” sort of pain. In psychology, what most people call “hurt feelings” is called social pain. Anecdotally, we use the same language to refer to physical pain as social pain, and only recently have we had the technology to investigate whether the two concepts overlap actually, or just metaphorically.
About 4 years ago, Dr. C. Nathan DeWall of the University of Kentucky and his colleagues published a study on social pain. In this study, he asked the very simple question:
To answer this question, he conducted 2 experiments. In the first experiment, he recruited 62 undergraduate students. These participants were randomly assigned to receive either 1000 mg of acetaminophen per day (500 mg in the morning, and 500 mg before bed) or a placebo pill. The participants were prescribed their respective pills for 3 weeks. During these 3 weeks, the participants also completed daily reports of their “social pain.” These included items such as, “Today being teased hurt my feelings.”
At the end of the three weeks, they found that participants taking acetaminophen experienced declining reports of “hurt feelings” throughout the study. In comparison, the participants taking the placebo demonstrated no change in their reports of daily hurt feelings. Since the participants were randomly assigned to either receive the acetaminophen or the placebo, the reduction in hurt feelings over the course of the three weeks was likely caused by the effects of acetaminophen on the central nervous system’s recognition of pain.
Dr. DeWall then asked whether the effects of acetaminophen on social pain corresponded to neural networks in the brain. What we know from the past 2 decades of neuroimaging research, is that people who have lesions in the anterior insula and the dorsal anterior cingulate cortex report not being bothered by physical pain, and are less sensitive to social rejection and loss. Thus, Dr. DeWall was interested in whether acetaminophen use would result in differences in neural activity in response to social rejection in these two areas.
To answer this question, he recruited another 25 undergraduate students and randomly assigned them to receive either acetaminophen or a placebo. Participants took their assigned pill every day, morning and night, for 3 weeks. At the end of the 3 weeks, the participants came to the lab to participate in an fMRI, or brain imaging session. While in the scanner they played a ball toss game that, unbeknownst to them, was designed to make them feel socially rejected.
The ball toss game had 2 parts. In the first part, the participant and two other players virtually played catch with each other. In the second part, the two other players stopped throwing the ball to the participant after 3 possessions. This is likely to prime the participant to think and feel socially rejected.
Dr. DeWall and his colleagues found that participants who had been taking acetaminophen for the past three weeks demonstrated less activity in the areas of the brain that are responsible for experiencing pain, anterior insula and the dorsal anterior cingulate cortex, compared with the placebo group. Thus, taking a daily dose of acetaminophen caused their brain to be less sensitive to social rejection.
So, am I telling you to start taking acetaminophen every day to feel less sensitive? NO, absolutely not. These studies were conducted with a very small number of young and healthy people, and taking any medication should be a decision made with the advice of your personal physician. Furthermore, I'm not convinced that not having hurt feelings would be a good thing. Experiencing hurt feelings may be a good thing in the long run, as those experiences will teach you who in your life is a reliable and supportive friend, and who is not. Evidence to support this notion is that Dr. DeWall also collected information on positive emotions throughout the study, and the participants in the acetaminophen group didn't report more positive emotions, even though they had fewer experiences of hurt feelings.
What this study should remind you of is the importance of feelings and their relevance to development and well-being. Given that humans are dependent on adults for a relatively long period of childhood, being able to express “hurt feelings” at separation from a caregiver would have been adaptive. It completely makes sense that physical and social pain would be neurobiologically intertwined. Given that we now have a wealth of information to support that the brain responds similarly to physical and social pain, I would like to challenge the notion that fault can only be placed on people who inflict physical pain on others. Put another way, every time a person says something hurtful to another person, the brain might as well be getting punched. This has implications that we don’t necessarily understand yet. People who are physically abused or live in conditions of chronic pain have long term negative repercussions, but very few people understand the long term consequences of living in an environment filled with hurtful and rejecting social interactions. If these experiences act on the central nervous system in a similar way, ought the long term negative consequences overlap as well? In light of this reminder, I leave you with a quote from my favorite book:
“Shall we make a new rule of life from tonight: always to try to be a little kinder than is necessary?” ~ J.M. Barrie, Peter & Wendy
Dewall, C. N., Macdonald, G., Webster, G. D., Masten, C. L., Baumeister, R. F., Powell, C., ... & Eisenberger, N. I. (2010). Acetaminophen reduces social pain: behavioral and neural evidence. Psychological Science, 21(7), 931-937.