Even when adults cry out of happiness—at, say, a reunion or the birth of a healthy baby—it’s still connected to this same idea of attachment. We cry happily when we recognize, deep down, that every connection we make in life could end up severed.
The similarity between “happy” tears and “sad” tears also exists in the biochemical and physiological processes that underpin all types of emotion-based crying.
Years ago, the chemist and tear expert Dr. William Frey published a number of highly cited studies showing that when we go through any emotion-based crying (happy and sad), our tears contain stress hormones and other chemical toxins. Frey took this as proof that crying is about the removal of stress hormones from our bodies in order to maintain emotional homeostasis. The actual health benefits of this process have been debated—Vingerhoets suggests that instead of asking, “does crying bring relief?” we should be asking, “for whom and in what conditions does crying bring relief?”
Either way, it’s useful to consider tears as the “outward signs of abrupt shifts in neurophysiology,” write researchers Jay Efran and Mitchell Greene. More specifically, crying, whether happy or sad, is the external result of an internal body shift, when the sympathetic nervous system — the “fight or flight” mechanism— gives up control of the body to the parasympathetic nervous system —a.k.a. “rest-and-digest.”
Think about the last few times you’ve cried. Regardless of what it was that ultimately caused you to tear up, most likely, you didn’t cry during the height of the experience.
For example, say you’re having a terrible day at work—just the most awful eight hours you could imagine. No matter how stressful it gets, it’s unlikely that you’ll cry, because your body won’t let you. In moments of intense stimulation, your sympathetic nervous system kicks into gear. And during this time, your body has no use for crying; it is stressed and aroused, focused and functional. It says “deal with it,” so you do; you go pick up the lunch that was never delivered, you re-write the report that you lost when your computer shut down, and you walk the extra 15 blocks when your train stopped running.
But eventually, the stressors end. When you finally get home, and you kick off your shoes, and sit alone on your couch, in that calm quiet moment, that’s when your parasympathetic nervous system kicks in. It’s at the moment of that switch that we cry: the transition between a sensory overload and a moment of calm.
While there have not been any peer-reviewed studies of crying on airplanes up to this point, there was study published in 2004 that considered grieving while driving, and in it, researchers found that grievers often “hold off grieving until they are alone and behind the wheel. They are free then from the distractions…this time by themselves provides them with the freedom for emotional processing and relief.”
The same thing occurs when you finally sit down in your seat on an airplane: your body shifts gears. You’ve finally reached the end of what was likely a full day of getting to the airport, and could have been weeks of preparing, or even years of an important life phase culminating in an end and new beginning. And that’s the time to have a good, long cry.
Speaking of cars: Recently the writer, director, and comedian Louis C.K. made the social media rounds in a video clip discussing crying on Conan O’Brien’s talk show. C.K. begins by explaining how hard it is to simply sit with yourself these days, when access to cell phones and our extended social networks have conditioned us to imagine ourselves as always connected. His argument is that if you take those things away, we fall to pieces very quickly—he talks about breaking down into tears whenever he’s on long drives in a car. He couches it in humor, but he’s being dead serious.
“You need to build an ability to just be by yourself and not be doing something —that's what the phones are taking away, and that's being a person, right?” C.K. asks.
When you’re alone, in a situation where you can’t can’t fiddle with your smartphone or turn your anxieties outward toward your social network, the apprehensions and fears of loneliness quickly overtake you. Then you have no choice but to face the fact: you’re a person, in the universe, and you are in some way big or small, alone here. You might cry.
“Crying seems to occur in situations where action makes no sense,” Vingerhoets says. “Where [action] is not needed or where you can’t act because you feel hopeless or are helpless.” Grief is the paramount example: after a death, there’s no explanation and there’s nothing a person can do except work through their feelings. “When there’s no reason to fight or fly, you just have to deal with your emotions,” Vingerhoets says.
This is what it’s like on a plane—it’s that rare situation where you are alone for a long period of time and there is nothing you can do. You are far from the world and you’ve given up control: your life is literally in the hands of the pilot and crew.