Why Painkillers Impair Empathy

Pain empathy varies in intensity

Source: Canva/Pixabay BM10777

Painkiller medications reduce our empathic responses. Research shows that when taking acetaminophen (paracetamol) we show significantly less empathy for others’ pains and or joys. Although this is interesting in itself, the explanation of why it happens reveals the crucial role that somatic (body) sensations play in our comprehension of the world.

Survival requires us to be able to rapidly ‘read’ others and so there have been strong selective pressures to unconsciously nonverbally assess other people (and other animals). By studying the evolutionary age of the relevant neurological processes, it is thought that before the evolution of language, we understood others by sharing their experiences, taking on how they felt and feeling with them. We and other mammals retain this ancient intelligence; this ability to feel with others and thereby read the situation.

We often use the word 'empathy' to describe a deep understanding of others. A common definition is the understanding and sharing of someone else’s experience. There are two elements: comprehension and shared experience. It is this ‘sharing’ part that is relevant because it is somatic sensations that can be dulled by painkillers.

How do painkillers dull empathy?

When we see or hear about others experiencing pain, we share an aspect of what it feels like as if we were in that same pain ourselves. Mostly, pain contagion happens without our awareness; we might notice a tingle of discomfort or we squirm with displeasure. If I see someone stub their toe, my same toe tingles. If you watch someone bang their head, your head may feel weird for a split second.

The reason we feel with others is complex but—putting it simply—the process of perception is not merely a mental process; it is also embodied. We translate what we sense in the outside world into internal 3D experience using an array of ‘perception-action mechanisms’. This produces somatic empathy – a sense of shared experience. Perceiving pain in others involves simulating their experience in our own body.

A small proportion of people (1-2%) don’t experience pain contagion. They can work out mentally how someone else might be feeling but they can’t share the experience of anyone’s discomfort. At the other extreme, a similarly small percentage of people experience excessive pain contagion and find themselves in discomfort much of the time simply from what is happening to others around them. Such a person is unable to watch a violent film or listen to a traumatic story as it impinges on them physically.

Most of us experience moderate pain contagion and this is entirely normal.

The importance of discomfort

In order to self-regulate we need to feel what is going on inside of us. If I feel thirst, I drink. If I feel scared, I remove myself from the scary situation. Without a sense of fear or thirst, I would not survive for long. Feeling discomfort is essential for self-regulation. Feeling the discomforts of others is also important information. It is an essential ingredient of the social glue that binds us. When we take painkillers to numb discomforts, we not only kill our own pain but the ability to experience pain contagion and thereby dull the somatic component of empathy.

We are not talking about super-strong painkillers such as ketamine or codeine. The humble paracetamol, taken by a quarter of all US citizens every week, is sufficient to reduce empathy. Some researchers speculate that the rise in use of painkillers is producing a "low-empathy" society. Pain killers don’t just take the edge off our personal aches and pains; they dull our ability to ‘feel’ our world.