Love, Actually is one of my favorite movies. In it, moviegoers see all the shapes and sizes of love. Earlier this month, we focused our attention on the genetics of romantic love. In our continued tribute to Valentine’s Day, this month’s Gene Therapy will spotlight research on another sort of love – the bond between friends.
What is it that makes your BFF well, your BFF?
Is it your shared love of half-priced margaritas? Is it the fact that she greets you at the door in matching flannel pajamas to watch season 1000 of Dancing with the Stars? Is it that she remains non-judgmental, no matter how many spoonfuls of raw Pillsbury cookie dough you eat right from the tube?
It could be any of those things. Or, it could be your DNA.
A recent study found that friends are more genetically alike than random strangers. They also found that friends were on average around two-thirds as genetically similar as married couples, which past research has suggested tend to be another social grouping impacted by genetic selection.
Why does this happen?
A proposed theory is social homophily, which is the idea that friends are more “genetically similar to one another because they form their friendships partly on the basis of shared characteristics”. And many of those traits, such as appearance and education, can be traced to genetics.
“Wait, my love of affordable margaritas is genetic?”, you ask.
Well, maybe. But there’s more.
Social structuring, which may also be impacted by genetics, is believed to shape this bond. This is the idea that people are drawn to others in their own social environment (i.e. at school, church, or extracurricular activities).
So, what does this all mean?
Basically, this underscores how closely genetics and social interactions are linked. But it’s unclear which shapes which. The jury is out on a definitive cause and effect but there seems to be a strong correlation.
The bottom line: Genetics actually is all around. Even in your raw cookie dough.