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Swedish researchers repeated the calculations of the British anthropologist Robin Dunbar, who revealed in 1992 the relationship between the number of friends and the size of the brain of humans and primates, and found no confirmation of his theory.

"The theoretical basis on which the Dunbar number was derived turned out to be very shaky. The brains of other primate species process information quite differently than humans do, and other factors affect the structure of their groups, including what they eat and what predators attack them. In addition, the typical size of social networks among people varies greatly, " said Patrick Lindenfors, associate professor at Stockholm University (Sweden), whose words are quoted by the press service of the university.

The so-called Dunbar number was derived in 1992 by the famous British anthropologist Robin Dunbar. He drew attention to the fact that the typical size of social groups among primates was somehow related to the size of their brain in general and the area of the cerebral cortex in particular.

To test this idea, a British researcher compared the brain size of 38 primate species, which generally confirmed his calculations and allowed him to estimate the maximum number of social connections between people. According to his calculations, this value is about 150 individuals.

Many other anthropologists did not agree with Dunbar's ideas, as Lindenfors notes, but they attracted interest both from the scientific community and from ordinary people. As a result, the Dunbar number began to be widely used in the development of online projects, in the organization of business and government structures, as well as in many other projects that affect the lives of hundreds and thousands of people.

Swedish anthropologists are interested in whether it is possible to more accurately determine the Dunbar number, using the latest statistical methods and refined data on the size of the brain and cortex in a large number of primates, which have been collected by zoologists over the past three decades.

In total, scientists have obtained accurate data on the size of the groups and the brain for seven dozen species of primates, including humans. They analyzed and compared these data sets, using several statistical techniques at once to calculate the Dunbar number.

These calculations led Lindenfors and his colleagues to question whether a statistical relationship between the size of the primate brain and the number of social connections in their groups exists in reality. The scientists ' skepticism was due to the fact that the spread between the values of the Dunbar number, which were calculated in different ways, was too large. In some cases, it was more than 500 individuals, and in others it was less than ten.

Such a wide range of values, as the researchers note, in principle does not allow us to calculate the Dunbar number with any acceptable accuracy, which in fact makes it meaningless. For this reason, Swedish anthropologists suggest a cautious approach to the implementation of projects based on the assumption of their British colleague.

The article is published in the journal Biology Letters

Photo - Chimpanzees in search of honey © Andrew Bernard
Source: ITAR-TASS, sci-dig.ru