People are social animals. And, of course, some people are more social than others. Think Penny and Sheldon from The Big Bang Theory to get a feel for the range.
A new study has found a genetic difference that might explain at least part of this spectrum of sociability. It might even help us understand how someone can go from being shy as a child to outgoing as an adult or vice versa.
The gene involved, the oxytocin gene, makes perfect sense as it is intimately involved in sociability. It has the instructions for making the hormone oxytocin and this hormone forges bonds when falling in love, plays a critical role in mother-child bonding and improves people's ability to read emotions accurately in the face of another person. Oxytocin isn’t the whole story, but it is almost certainly a piece in these puzzles.
In this new study, the researchers collected the spit of 121 healthy volunteers and looked at their oxytocin gene. But the team wasn't looking at the A’s, G’s, C’s and T’s that have the genetic instructions for making oxytocin. Instead, they were looking at something that decorates the gene and affects how much oxytocin the gene says to make. That something is called methyl groups.
In general, the more methylation a gene has, the less active it is. And the less active it is, the less product it makes. So an oxytocin gene with a lot of methylation will make less oxytocin. And an oxytocin gene with just a little methylation will make more of it.