A Science Journalist On The Link Between Loneliness & Sleep
According to Zaraska, the reason has evolutionary roots: “In our evolutionary past, when you were lonely, it meant you were outside of your tribe. You were kicked out, lost, or whatever. And suddenly, you’re alone in the [desert] with all these wild animals around.” Essentially, you wouldn’t want to sleep too deeply in that situation, because then you’d be vulnerable to predators in the wild. Rather, you’d want to stay vigilant, awake, ready to take on any mountain lions that come your way.
Of course, this is not so applicable to modern life (unless you frequently wander the desert). However, says Zaraska, your body didn’t exactly shake that innate response as humans evolved. That’s why when you feel lonely and isolated—just like you might if you were exiled back in the day—that same stress response may have you feeling wired. Research even shows how chronic isolation can disrupt a number of neuroendocrine factors that can lead to higher stress response. In more basic terms: “Still, when we are feeling lonely, we feel that we’re outside of the tribe,” Zaraska explains. “And we look out for the lions.”