Strangers Show Unexpected Effect on Pain Relief in Test of Xenophobia

"We were surprised, but happy."

When researchers from northern Europe began their new study on how differences in nationality might impact doctor-patient discussions about pain, their hypothesis, based on humanity’s most basal, xenophobic instincts, was bleak. But their results, published Tuesday in The Proceedings of the Royal Society B, reveal an unexpectedly bright outcome: Strangers might actually be better at helping people psychologically process pain.

Grit Hein, Ph.D., a professor of translational social neuroscience at the University of Würzburg in Germany, first got the idea for her study while observing the doctors in a clinic near her lab. “Many doctors and nurses come from all over the place, they don’t necessarily share the same nationality or social group as the patient,” she tells Inverse. “So our question was: Does this have an impact? And we took the issue of pain, because we know that the way we process pain is very strongly influenced by psychological factors.”

It might seem like a stretch to say pain has anything to do with our feelings toward strangers, but previous research has confirmed that humans are tribalistic jerks. We prefer our own ingroups and are mistrusting of strangers. On top of that, other studies show that the experience of pain is modulated by social factors. For example, Hein explains, while we experience physical pain in the body, that pain may actually feel worse if you’re outside your element. Taking this information into account, she had a sinking suspicion that people might report greater levels of pain when being treated by a doctor who was unlike themselves.

Interestingly, her study proved her wrong.

Subjects who received treatment from an "outgroup" member tended to rate lower experiences of pain post-treatment 

Proceedings of the Royal Society  B 

For the study, Hein divided 20 Swiss male participants into two groups. All of them received mild shocks to the back of the hand, but one group received “pain treatment” either from a member of their own social group (a Swiss person) or from an outgroup — in this case, a person from the Balkans, whose “presence is often portrayed as problematic,” according to the authors.

Here, she noticed something puzzling. Contrary to the predictions of her hypothesis, people who were treated by an individual from the Balkans tended to report less pain after treatment than those treated by a Swiss person.

“A lot of studies show that people prefer doctors or treatment providers from their own social group because it’s about trust or similarity,” Hein says. “What we find is the opposite. That in a certain way, especially for people who have pretty strong prejudice against people from different social group, these people are positively surprised when they experience help from another person.”

During the experiment, Hein also scanned the brains of the participants for changes in activity patterns twice. The first scan came after the shock but before their “pain treatment,” and the second happened after the treatment. This neural data showed that the Swiss men who received treatment from the Balkan individuals had far higher activation in the anterior insula, typical of the “learning signal” that this brain region shows when it learns to re-contextualize its experience of pain. The team took this as evidence that the brains of those participants were teaching them that the pain is temporary, helping them minimize their experience of it.

The "learning signal" seen in the brains of people who received treatment from an outgroup member

Proceedings of the Royal Society B 

“I think this is pretty fascinating,” says Hein. “Even if you have the same pain again, even if you have the same painful stimulus, you feel less pain. This is because the brain learns that it experiences pain relief in this situation.”

It turns out that feeling surprise at receiving good, pain-relieving treatment from a member of an outgroup is an important behavior. In animals, Hein explains, studies shown that the feeling of surprise tends to speed up the learning process. This could partially explain the pattern she saw in her participants: When people were surprised by good treatment from a person from the outgroup, their learning process sped up, helping them re-contexualize their pain faster.

On the whole, Hein says her findings are a beacon of hope in an otherwise bleak field of research.

“In the beginning, people were puzzled by it, but when we understand why it happens of course this is more interesting than the expected findings,” she adds. “We were surprised, but happy.”

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