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Genetics

The genes of friendship

When we make a new friend or become part of a group it is because we experience some kind of affinity toward these people. It appears that this affinity could be mediated by the action of our genes, according to a study published in the journal PNAS by scientists at the University of California at San Diego

XAVIER PUJOL GEBELLÍ | JANUARY 21st, 2011

Studies on the social behavior of animal species in their infancy have just started to look at whether or not genes mediate certain attitudes or interests. However, some evidence is arising, although many scientists still consider it coincidental, which points to the existence of common genes in certain groups or underlying certain behaviors. The latest study to produce such results, published in the journal Proceedings of the National Academy of Sciences (PNAS), reveals the presence of the DRD2 gene in groups of friends.

Does this finding suggest that when we feel an affinity for someone it is because we somehow perceive the presence of this gene in the other person? That is one possibility among many others, concludes James Fowler , lead author of the article, for whom the biology of online social networks is an undiscovered country. "Our ability to make friends and maintain friendships over time is something that defines us as humans," he said, so it "is likely" that in our genetic code there is a sequence that explains this phenomenon.

On the origin of a social network

From a sociological or even psychological point of view, the formation of a group seems well defined. Common likes or hobbies, a certain affinity, interests and objectives in the short or long term, coinciding in time and place are all factors that explain how and why a group is formed and stays together.

New information technologies also add a new factor of cohesion, since they bring to light elements that may be attractive or overlapping between individuals who may not have ever met without the publicity factor that these different tools on the Internet offer to users. In any case, the mechanism of online social networks continues to be an amplification of the classical group model.

The CYP2A6 gene is associated with open-minded people and DRD2 with alcohol consumptionThe question is, however, if there is a biological explanation to support the formation of a group or even online network. According to the study by Fowler it is a possibility. In his research on different groups, he found that the DRD2 gene was present in groups of friends who were very tight-knit. The result, far from causing shock, seemed to confirm a fact already known, since this gene is linked to a propensity to consume alcohol and appears to be at the root of addictive phenomenon. "The ability of drinkers to build relationships and join groups is well known," Fowler said. The finding, he said, extends the vision of the relationship between friends.

Another gene, CYP2A6, appears to support the theory that genes also determine social behavior. The gene in question is commonly associated with "open-minded" people and it has been observed that these individuals tend to relate to people who do not have the same CYP2A6 gene. According to Fowler, this negative correlation could reflect people’s “unconscious” search for those who are "genetically different." That is, it is the opposite of the case of the DRD2 gene.

Health and reproduction

Both genes, according to Fowler, could indicate issues that go far beyond the identification of similarities or differences. They could indicate, for example, groups of people whose ancestors were part of a specific population or even the same family, something which would explain the willingness to establish relationship, even for reproductive ends.

Genes indicate a predisposition and environmental influences do the rest In this context, the opposite case could indicate a strategy to increase the genetic variability of offspring, an aspect that is shown in individuals who, unconsciously, select partners with immune systems which respond differently in order to ensure healthy descendants.

Regarding the biology of behavior, the two identified genes are only "the first, disconnected pieces" of what is presumably written into the genetic code. "There are multiple factors, some more subtle than others, that affect behavior," Fowler said. Most likely, those which have now been found, along with others associated with addictive or violent behavior, do nothing beyond determining a bias. The influence of the environment is responsible for the rest.

BEES’ SOCIAL GENE
Vitellogenin, a gene involved in the production of eggs of many animals, including insects, seems to clearly determine the social behavior of bees. Scientists have discovered that this gene plays a central role in the natural tendency of bees to feed their young, in the specialization of groups dedicated to the same task, and longevity. These are all elements related to the mechanisms of socialization in the hive. Further studies are trying to verify whether there are similar genetic mechanisms in other social animals.

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