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The illustration shows graphically superimposed portraits of the participants who were treated with placebo (left) or with E. coli bacteria
Photo: Artin Arshamian / Karolinska Institutet / dpa
People can tell from the face of sick people that they are not healthy.
Even peoples distant from civilization, who hardly or not at all know western faces, can identify sick western Europeans with great certainty.
This is the conclusion of a study by the Karolinska Institute in Stockholm published in the journal Proceedings of the Royal Society B.
It is known that mammals have the ability to recognize sick conspecifics.
This is crucial in order to reduce contagion and increase your own chances of survival.
An international research team led by Artin Arshamian has now looked at the extent to which people can do this.
Above all, they wanted to know whether they would be able to do this in the case of illnesses in people from other cultures with whom they had little or no contact so far.
Ultimately, they investigated whether the ability to recognize sick people is a universal human quality.
Subjects intentionally infected
For the study, the experts infected a good dozen Swedish test participants with bacteria or gave them an ineffective placebo.
Two hours later, the faces of the participants were photographed.
These recordings were then presented to 53 other participants from Sweden as well as more than a hundred people from five other populations around the world.
You should indicate which of the faces hid sick people and behind which, healthy people.
Three groups were small hunter-gatherer peoples from Thailand, Malaysia and Mexico.
Accordingly, they live in rainforests and the desert, and they have little or no access to television or the Internet.
The other participants were city dwellers from Thailand and Mexico.
Habit doesn't help
"There were group differences, but Western participants who observed faces from their own community were not systematically better than non-Western participants," writes the research team.
In other words: All groups were able to identify a sick person with a high probability of being hit.
The result is surprising, said Arshamiane.
It was assumed that those who were more used to Western European faces had an advantage over the other groups.
"But that was not the case at all," said Arshamian.
The Swedish test group was no better than any of the other groups, although they had known healthy and Swedish faces all their life.
In further projects, the scientists now want to investigate, among other things, whether sick and healthy people can also be differentiated on the basis of their movements.
jme / dpa
