Empathy is the heartbeat of healthy relationships. Without it, there is limited scope for connection and understanding – arguments heat up, intimacy cools down, small issues become big ones, and relationships break. New research has made some startling findings in relation to the popular painkiller that reduces empathy.

Empathy is the ability to understand what another person might be feeling or thinking. It involves being able to see things from another person’s point of view, even when it pushes against our own. This means being able to stay curious and open to another person’s experience, while at the same time being able to tap into our own emotional bank to understand and interpret the other person’s experience.

Our own individual stories may differ vastly, but behind every story are feelings that are familiar to all of us. At some point, we have all found ourselves knee-deep in the messiest of human emotions – anguish, loss, shame, grief, fear, jealousy, disappointment. Empathy lets us tap into our own pain to understand the pain of others. New research published in the journal Social Cognitive and Affective Neuroscience has found that our ability to do this may be interrupted by a common painkiller. 

The research found that when participants took acetaminophen, the main ingredient in Tylenol, they were less responsive to the pain and suffering of others, compared to those who did not take a painkiller. (Acetaminophen is also known as paracetamol, the main ingredient in Panadol.)

Acetaminophen is found in more than 600 medicines. It is the most common drug ingredient in the United States and is used by about 23% of American adults each week.

The Popular Painkiller That Reduces Empathy – The Research

The research consisted of a number of separate studies. In the first study, 40 college students were given 1000mg of acetaminophen while the other half were given a placebo. The students had no idea whether they had taken the drug or the placebo.

After the participants had waited for an hour for the drug to take effect, they read about eight individual people who were each experiencing some sort of physical or emotional pain. The stories included one about somebody who had received a cut with a knife that went down to the bone, and another about a person whose father had died. The participants had to rate the pain they believed each person would be experiencing from 1 (no pain) to 5 (worst possible pain).

Those who had taken the acetaminophen rated the severity of pain as lower, compared to those who had taken the placebo.

In the second study, 72 college students took acetaminophen and 72 took the placebo. They were then exposed to four 2-second blasts of white noise from 75 decibels (about the noise of an average vacuum cleaner) to 105 decibels (the noise of a power lawn mower or a live rock concert). They then had to rate their experience of the noise on a scale of 1 (not at all unpleasant) or 10 (extremely unpleasant). They were then asked to imagine the level of pain the same noise blasts might cause someone else.

Compared to those who took the placebo, the people who took the acetaminophen rated the noise blasts as more tolerable for themselves, and more tolerable for others.

Similar results were found when participants were asked to watch an online game which involved two players actively excluding a third person from playing. Each participant had met and socialised with the three people involved (the two playing and the one excluded) briefly before the study. Those who took the acetaminophen rated the pain of the excluded person as less severe, compared to the ratings by those who took the placebo.

‘We don’t know why acetaminophen is having these effects, but it is concerning … (T)hose who took acetaminophen showed a reduction in empathy. They weren’t as concerned about the rejected person’s hurt feelings.’ Baldwin Way, co-author of the study and assistant professor of psychology at Ohio State University.

The results support previous research that found the same part of the brain is activated when people experience pain, and when they imagine other people feeling the same pain. It makes sense then, that when medication is taken to reduce a person’s own experience of pain, it will also reduce the ability to feel the pain of other people.

In short bursts, reduced empathy might not seem such a big deal, but it only takes a moment for arguments to fever up.

‘Empathy is important. If you are having an argument with your spouse and you just took acetaminophen, this research suggests you might be less understanding of what you did to hurt your spouse’s feelings.’ –Baldwin Way.

Earlier research found that acetaminophen reduces the pain of social rejection (as in the pain of a breakup), but research since has found that that acetaminophen also flattens positive emotions, like joy. 

The researchers are now turning their attention to ibuprofen, another common pain medication, to see if there are similar results.