You a party animal? Blame your genes...

Salve salve, a todos! Ando meio desplugado do mundo exterior graças à uma tese de mestrado atrasada, mas não podia deixar de postar este artigo, retirado do "The Gazette" e escrito por Shannon Proudfoot (Canwest news service) hoje...

NEW RESEARCH PUBLISHED Findings defy previous conclusions

Whether you’re the life of the party or a perpetual wallflower is partly inscribed in your genes, new research shows.

The findings fly in the face of the previous theory that social networks are purely a product of people’s environment and experiences, says James Fowler, a professor of political science at the University of California San Diego who studies behavioural economics and the impact of social networks on health.

“This is really the first evidence that human beings are not interchangeable in social networks,” he says.

“It really suggests that we gravitate toward a certain part of the social network. You can’t take someone who’s naturally inclined to be the life of the party and force them to sit on the sidelines.”

In comparing the social networks of identical twins – who share 100 per cent of their genes – with those of fraternal twins who share an average of half the genes that vary between humans, the researchers found the identical twins’ social groups more similar than those of the fraternal twins, pointing to a strong genetic effect.

The number of friends someone has and how many of their friends are friends with each other are shaped half by nature and half by nurture, their calculations determined. People’s tendency to occupy the nucleus of their social networks or hover on the periphery is about onethird “heritable,” or shaped by genes, it also found.

“If you’d asked me before we looked at these things, I would have said genes were maybe 10 or 20 per cent of the story,” Fowler says. “So to find out that they were half of the story was quite surprising.”

The results suggest that genes play a big role in influencing how much we attract people to be our friends – which makes sense, given people’s physical and personality differences, he says. But it also means our genes have an impact on how inclined we are to act as catalysts of friendship between our acquaintances.

“My genes have an impact on whether two of my friends are friends with one another,” Fowler says. “That is, one person’s genes influence the decision of two other people to become friends.”

The paper is co-authored by Christopher Dawes of UCSD and Nicholas Christakis of Harvard University and published in the journal Proceedings of the National Academy of Sciences. Fowler and Christakis’s previous research found that obesity, smoking and happiness are all “socially contagious” and passed on through social networks.

“The big hypothesis here, for which this paper is just the first step, is that one of the reasons why genes impact health outcomes is because they affect the structure of social networks,” says Fowler.