Making the Connections Between Loneliness and Health
March 7, 2012
by Robin Tricoles
Loneliness may seem to be a simple state of mind. But it's not. There's much more to this complex emotion than meets the eye. Loneliness can be your friend, your ally, even your personal watchdog. Or it can be your adversary or your enemy--if it stays too long.
You see, loneliness has been of service to humans and other social species for millennia. But only in small doses. In large protracted ones, loneliness increases morbidity and mortality even among seemingly hardy individuals.
Here's why. Throughout time, social species such as squirrels, whales, and humans thrived when they banded together to fend off predators, care for their young, forage for food, and learn from one another. In essence, social animals were busy forming a super-organism that maximized its chances for survival and reproduction. Meanwhile, hormonal systems, cells, genes, and brains adapted to reinforce the gains realized from their united front. One of those adaptations: the brain's growing sensitivity and aversion to loneliness.
To be clear, loneliness isn't about being alone. It's about how an individual perceives his or her connections to others. "Humans are capable of deception, betrayal, exploitation, and murder as well as empathy, compassion, loyalty, and prosocial behavior," social neuroscientist John Cacioppo says. However, given the fluidity of social hierarchies friends can become threats at any time, he explains. That's why perception is key to distinguishing loneliness from just being alone. It's one's perception of being socially isolated that affects the health and well-being of the body.
Even if one happens to be a fly. Scientific studies have shown that social isolation cuts the lifespan of fruit flies. Rodents suffer, too. In mice, isolation increases obesity and type 2 diabetes. Other research has shown social isolation is linked to a drop in immunity, sleep disturbances, and a rise in blood pressure and stress-hormone levels.
Intriguingly, loneliness is tied to genuine physical pain as well. That's because loneliness activates the same neural pathways as physical pain. It's thought that the physical pain that accompanies loneliness evolved to alert us that our connections to others are weakening and that these connections need to be strengthened.
In one study, Cacioppo showed lonely and non-lonely people unpleasant images of others and unpleasant images of scenes. When social, in contrast to nonsocial, images were presented, the visual cortices were more active and the temporal parietal junction (a region involved in taking the perspective of others) was less active in lonely compared to non- lonely individuals. When we're lonely our brains are more sensitive to perceived social threats and self-preservation, explains Cacioppo. "It's social connections that give us a buffer from threats," he says.
Something else to consider: connections also facilitate social learning within a group and ultimately social norms, says Cacioppo. Take for example, a small child who misbehaves while playing with his peers. When he's isolated from the rest of the group but still able to see his playmates carrying on without him, he feels ostracized, lonely. He feels pain. Once comforted and re-admitted to the group, the child's pain subsides, but the memory of the importance of playing well with others lingers. In essence, the temporary pain of loneliness helps us learn what's socially acceptable and what's not. "That pain can teach us to be better citizens as long as the pain is not chronic," says Cacioppo.
John Cacioppo is the director of the Center for Cognitive and Social Neuroscience at The University of Chicago. His fresh way of thinking about loneliness contributed to Cacioppo's receipt of the Society for Personality and Social Psychology Theoretical Innovation Prize in 2008. The National Institutes of Health honored him with the MERIT Award for his work on loneliness and aging. Cacioppo has received numerous awards from various scientific societies.