Back in the day, when the fam would get together at my parents’ house, I would enjoy shuffling through their box of old photos. Looking at childhood pictures of myself and relatives, it was natural to compare our adult selves to the old pictures and look for similarities – emotional expressions, gestures, etc. – that have carried on through the years and are (were) a part of who we are (became) today. It’s always amazing what you think you can see, and if you’re like me, you may be somewhat amazed by how much of your adult self was already in full swing as a child. The manner in which the developing brain confers such stability over time and over generations (now I see my own childhood traits in my son – yikes!) is of course a timeworn question among families and scientists alike.
That the genome would contribute to cross generational parent-child similarities in personality and temperament is fairly obvious, but not so apparent is how the genome interacts with the environment to exert an influence on psychological development. Along this line of inquiry, a research article entitled, “Influence of RGS2 on anxiety-related temperament, personality, and brain function” by Smoller and colleagues [free access] provides an amazing perspective – from a single gene. RGS2, eponymously named as a regulator of G-protein signaling, was first identified as a factor that regulates emotional behavior in mice [PMID] and subsequently as a risk factor for schizophrenia [PMID] as well as anxiety disorders in humans [PMID]. In the current study, the team examined the temperament of children (119 families), personality of adults (744 undergraduates) and brain activity in adults (55 participants) to ascertain whether the adult risk for anxiety conferred by RGS2 might be related to actions of the gene that occur much earlier in development – such as on the systems that regulate temperament in children. Specifically, they focused on behavioral inhibition in children (shy, avoidant, restrained in novel situations) and introversion in adults – as these traits have been associated with increased risk for anxiety disorders.
What is so interesting to me is that RGS2 (particularly the G allele of the 3′UTR SNP rs4606) was found to be associated with both childhood temperament and adult personality. Thus, an introverted adult who looks through an old photo album and sees themselves to have been a shy or inhibited child, may be experiencing – to a small degree – the effects of the RGS2 gene. The team suggests, via additional brain imaging-genetic studies, that RGS2 is of particular relevance to activity in circuits containing the insular cortex and amygdala – when subjects perform an emotional face matching task.
My own 23andme record does not contain the rs4606 SNP but does contain the data for rs1819741 where a T allele was significantly associated with introversion. Since I’m a C/T heterozygote, I guess I’ll have to look a bit harder at my old pictures to see signs of behavioral inhibition.