Common painkiller may make you less empathetic

Taking a popular painkiller may decrease your empathy for both the physical and social aches that other people experience, a new study has found.
Researchers at the Ohio State University in US found that when participants who took acetaminophen learned about the misfortunes of others, they thought these people experienced less pain and suffering, when compared to those who took no painkiller.
"These findings suggest other people's pain doesn't seem as big of a deal to you when you've taken acetaminophen," said Dominik Mischkowski, a former PhD student at the Ohio State University.
"Acetaminophen can reduce empathy as well as serve as a painkiller," said Mischkowski, who is now at the US National Institutes of Health.

The researchers conducted two experiments, the first involving 80 college students.
At the beginning, half the students drank a liquid containing 1,000 mg of acetaminophen, while the other half drank a placebo solution that contained no drug.

The participants then read eight short scenarios in which someone suffered some sort of pain.
Participants rated the pain each person in the scenarios experienced from one (no pain at all) to five (worst possible pain). They also rated how much the protagonists in the scenarios felt hurt, wounded and pained.
Overall, the participants who took acetaminophen rated the pain of the people in the scenarios to be less severe than did those who took the placebo.

A second experiment involved 114 college students, half of whom took acetaminophen and half took the placebo.
The participants received four two-second blasts of white noise that ranged from 75 to 105 decibels. They then rated the noise blasts on a scale of one (not unpleasant at all) to 10 (extremely unpleasant).
They were then asked to imagine how much pain the same noise blasts would cause in another study participant.
Results showed that, when compared to those who took the placebo, participants who took acetaminophen rated the noise blasts as less unpleasant for themselves - and also thought they would be less unpleasant for others.

In another part of the experiment, participants met and socialised with each other briefly.
Each participant then watched, alone, an online game that purportedly involved three of the people they just met.
In the "game," two of the people the participants had met excluded the third person from the activity.
Participants were then asked to rate how much pain and hurt feelings the students in the game felt, including the one who was excluded.
Results showed that people who took acetaminophen rated the pain and hurt feelings of the excluded student as being not as severe as did the participants who took the placebo.

The study was published in the journal Social Cognitive and Affective Neuroscience.