Social contact, stress, and the brain
One of the most powerful influences on our brains happens also to be one of the most powerful influences on our lives: other people. That ain’t no coincidence, folks – everything about us is related to our brains somehow. But it’s a fascinating area within neuroscience, because, believe it or not, scientists have just recently gotten around to documenting the way our connections with others influence the connections inside our heads.
The top academic journal Nature Neuroscience dedicated last month’s issue to “social neuroscience”, and there’s some cool stuff in there. One review paper talks about the various influences of social experience on our brain’s resiliency to stress. It’s been known for a long time that stressful experiences, especially early in life, cause the brain to develop in a way that makes it particularly vulnerable to stress, and also less cognitively efficient and able to learn. For example, it’s been found that abandoned children who were housed in those notoriously neglectful Romanian orphanages in the 1990s later had profound impairments in their cognitive ability, but – and this is the interesting part – the subsequent impairment was systematically less extensive, the earlier the children were taken into foster care. Other studies have shown that baby mice who are with their mothers have their stress/anxiety circuits kept in an immature state, but if they’re removed from their mothers, those circuits come online earlier in life.
Chronic stress prevents new neurons from forming and causes existing neurons to shrink in the cognitive parts of our brains (the hippocampus and prefrontal cortex, for you neuro-nerds), while in contrast the emotional parts of our brains (nerd alert: the amygdalae and the orbitofrontal cortex) grow and become more sensitive. Social stress (like loneliness, rejection, or conflict) is particularly powerful, and social contact is a powerful buffer against stress. One study showed that the brain’s stress response to impending electric shock was diminished significantly, just by having people hold their spouse’s hand!
It seems that cognitive ability, stress, and social contact are all intimately related to each other. So go out there and hug somebody; it might just make you smarter! And for heaven’s sake, call your mother and say thanks.