A child falling on the street might seem perfectly fine yet burst into tears upon being noticed by its parents. If your (male) partner has the flu, you will no doubt detect his overt expressions of suffering. As humans, we likely express our pain when we seek understanding or help from others. In extreme cases this might save our lives, so it is not surprising that the expression of pain, which is present in humans and non-human animals, might have evolutionary underpinnings .
However, expressions of pain are likely dependent on the context and in some cases, the portrayal of vulnerability might be disadvantageous. For example, it could lead to being invalidated, mocked or even exploited. We do know that pain behavior is greatly influenced such social surroundings, but there is very little research on how expressions of pain are affected by threatening social environments.
An earlier study from our lab showed that facial pain expression is reduced when in a threatening social environment, while at the same time self-reported pain intensity is increased . This result is partly in line with another study, which showed that if pain is the result of an intentional act it, is perceived as more painful than when it is the result of an unintentional act . This may point to a worrisome possibility: When individuals do not feel safe, their pain experience might be worsened, but at the same time, outward expression might be reduced. This could lead to underestimation of pain by others (e.g., health-care professionals) and suboptimal treatment, an already common problem .
In order to study this further, we used an approach developed by Peeters and Vlaeyen  to create a credible threatening social context. Here, a participant comes to the lab with another student, whom they believe to be a second participant in the same study….but in truth, are a confederate to the study. Using a bogus randomization procedure, the confederate is chosen to administer painful electrical stimuli to the participant. The confederate is instructed to administer either a set number of 10 electrical stimuli to the participant (control group) OR to choose to deliver between 1 to 10 electrical stimuli, all-the-while planning to deliver the full 10 (social threat group). So, while all participants received 10 stimuli in both groups, one group was led to believe that it was the intentional choice of the confederate to administer the maximum amount of stimuli, thereby creating a threatening social interaction. For every participant we assessed (1) painful facial expression, and (2) self-reported pain ratings. After participants received the electrical stimuli they were given a chance to administer painful stimuli to the confederate, and were assessed regarding their feelings at this opportunity. These two measures served as indications of (3) aggression and (4) empathy towards the confederate. Luckily for our confederate, we did not actually administer these electrical stimuli.
So what did we find? We recruited a total of 72 female participants from the general population in Leuven, Belgium. Unlike previous research, pain expression (1) and (2) pain intensity did not differ between groups. However, participants in the social threat group did demonstrate more aggression (3) to the confederate but there was no difference in empathy (4). So how can we make sense of this? One of the most likely reasons for this might be that participants perceived the confederate as threatening in both groups. After all, a total stranger administering painful stimuli to you might be threatening no matter what. As such, participants might show less pain expression in general, independent of group. This would be problematic, as it would point to the fact that individuals truly need an environment of safety and trust to express their pain. This is especially relevant for health-care settings, which often involve painful procedures administered by strangers. Even though health-care professionals might have the patients’ best interest at heart, we do know that especially individuals with chronic pain can often perceive treatment to be inadequate, invalidating or dismissive  and their pain is frequently underestimated . Social threat did have an interpersonal cost though, as participants returned more painful stimuli to the confederate in the social threat group. There was also preliminary evidence, based on a responder analysis, that perceiving someone else as threatening, also affects how threatening pain itself is perceived and how much empathy is felt towards the threatening other. In other words, perceived social threat was positively correlated with the threat value of pain and negatively correlated with empathy.
In conclusion, this line of research highlights the importance of taking interpersonal context and relationships into account when assessing pain in others. In light of recent research demonstrating that stigmatization and invalidation in pain patients are all too common [5,6], it should be our primary goal to create an environment of support, safety and trust, which ultimately facilitates assessment of pain and consequently, treatment itself.
For the full story, please check out the recently published article here .
About Kai Karos
Kai Karos finished his bachelor and research master degree at Maastricht University, the Netherlands. He is currently a doctoral researcher in the Research Group on Health Psychology at the University of Leuven (Belgium) under the supervision of Johan Vlaeyen, Ann Meulders and Liesbet Goubert. His PhD research concerns the effects of a threatening social context on pain perception and pain expression. These processes are mainly investigated using experimental laboratory research with healthy participants. For more information see here.
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