Science suggests certain neurochemicals & genes influence how social we are.

In the book, ‘Why We Love: The new science behind our closest relationships’, evolutionary anthropologist Anna Machin explains how the human brain is wired to release feel-good chemicals when we interact with others. This ensures we have the motivation to form and maintain relationships.

But what about those of us who don’t derive pleasure from being with people, who lack that motivation to connect? 

Are shy/schizoid/socially anxious/solitary people deficient in those feel-good chemicals? 

Are the brains of socially distant people different?

Well yes, that might very well be the case.

Machin says that, “We all exist at different baseline levels of the neurochemicals which underpin love and it is in part [my italics] this difference that impacts why we all experience love differently.” (And by ‘love’, Machin not only means romantic love, but familial and platonic love too). 

In other words, certain neurochemicals, along with our genes, do have a part to play in how social we are. 

Oxytocin

The most significant of these chemicals is oxytocin – also known as the ‘love hormone’, for the central role it plays in social bonding. 

Oxytocin helps to calm the amygdala – the part of our brain that triggers fear – to give us the confidence to approach people and instigate relationships. Those with low levels of oxytocin are therefore more likely to be shy and experience social anxiety. 

Our genes also have some influence here, specifically the oxytocin receptor gene – OXTR. The OXTR gene “determines sensitivity to oxytocin” and “more than any other gene” may influence “how big our social networks are” and “how likely we are to suffer from social anxiety.”

There are different versions of the OXTR gene and the extent of our sociability may be determined by which version – genotype – we carry. Those with the GG genotype have been found to “experience a greater neurochemical reward from their social interactions” than those with the AG or AA genotype. 

And if that wasn’t enough, there’s also methylation – a process which regulates gene expression. Methylation of one particular area of the OXTR gene “limits the expressions of the gene and by association our social abilities.” Brain scans of people with high levels of methylation in this area have shown “heightened activity in the prefrontal cortex” and this can make “engaging in social interaction… much more effortful.”

Dopamine 

Another neurochemical which influences our sociability is dopamine.  

Dopamine is a “vital neurochemical in the rewarding experience of love”. We get a hit when we interact with people, and it therefore acts as a motivator to ensure we maintain our relationships.

However, just like with oxytocin, levels of dopamine can vary between individuals. Some people will have a lot, others will have little. And those with low levels are likely to feel “listless and unfocused.” They don’t get the same hit when they connect with others, and they will have less interest in being sociable. People with depression and schizophrenia have been found to have lower levels of dopamine. 

There’s a gene associated with dopamine too – COMT.  Two different versions of this gene exist – Met and Val. 

A recent study found that Val carriers “exhibit lower dopamine levels in the prefrontal cortex” and were “more likely to display avoidant attachment in romantic relationships.” Interestingly, Machin writes that for “carriers of the Val allele of the COMT gene, love is… not one of life’s great motivators.” Their lack of dopamine means they “do not experience the drive or need for love.”

I wonder whether low levels of dopamine might also (partly) explain the schizoid’s lack of interest in relationships?

However…

There’s enough science to suggest that the brains of socially distant people might very well be different from those of our more sociable peers/colleagues/family members. We might have lower levels of the ‘love buzz’ chemicals, we might have genes that make us more indifferent to pursuing relationships.

But it’s important to point out that biology is not destiny here; an individual’s neurochemistry and genes are not the sole determinants of how social they will be. Environmental factors also have a huge part to play. 

That being said, it is interesting to note the role of nature in socially distant behaviour. 

References

All quotes taken from ‘Why We Love: The new science behind our closest relationships’ by Anna Machin, except “determines sensitivity to oxytocin” which is taken from this article: Oxytocin Genes (OXTR) & SNPs: Are You High or Low in it?