Why 'This Is Us' Makes You Cry So Much

Sterling K. Brown on 'This is Us' season 2 premiere
Sterling K. Brown as Randall on Episode 201 of "This Is Us," premiering on NBC on September 25. on Batzdorff/NBC

The second season of the hit television show This Is Us—also known as America's favorite reason to ugly-cry—premiered this week. The series has developed a sort-of cultlike following among viewers who enjoy having their heartstrings tugged on for an hour once a week (with commercial breaks).

Newsweek spoke with Jeffrey Zacks, associate chair and professor of psychological and brain sciences and professor of radiology at Washington University, as well as the coauthor of Flicker: Your Brain on Movies, about the science behind why the small (and big) screens get away with emotional terrorism—and why viewers keep coming back for more.

Why do we enjoy TV that makes us sad?

It's not just that we enjoy media that makes us sad. If you ask people why they're choosing something, they'll also tell you sometimes they're choosing something to feel happy.

Even weirder is if you ask people why they're sitting down in front of the screen in the first place or why they're picking a particular television show or film, they'll explicitly mention what's known as "mood repair." They're likely to give one of two diametrically opposed rationales. One of the rationales they'll give is mood congruence, such as "I was in a melancholic mood, so I wanted to watch Terms of Endearment." Or the person may say, "I was feeling down, so I picked a romantic comedy to cheer me up." I find that really interesting that people pick things that are either congruent or opposed.

Humans are hardwired to react to things in real life. Why do movies and television evoke the same emotions?

It's the way our systems are built. If it walks like a duck and quacks like a duck, our perceptual and emotional systems treat it like a duck. If you are confronted with a crying face or a smiling face, your emotions system responds to it as a crying or smiling face first and foremost. And yet, your brain has to do little extra work to reinterpret it as a fictive face.

In computational terms, the brain is taking input—patterns of light on the retina and patterns of pressure on the ears and so forth—and running computations on those that eventually result in behaviors such as crying or laughing. The kind of inputs you get when you see something on the screen are the same inputs if you see a real-world emotion.

Why do we get addicted to certain television shows?

The auditory and visual experience are like real life but cranked up a bunch of notches and purified. One analogy I make in my book is to highly processed foods. Sweet things produce a reaction from us. You now have factories where you can make things really sweet and really purify out the parts so the food really appeals to the sugar sensors or the fat sensors. And you can produce sensations that are much stronger than you get from natural whole foods. And I think media has the option to do that in exactly the same way. You can cut out the boring bits, you make facial expressions exaggerated, you can make it really big. A 20-foot-high crying face on the screen is a much more purified stimulus than you actually get when you're interacting with a real person.

Are there differences in the physiological responses to watching something from a screen versus seeing it in real life? Can those be measured?

A lot of what we know about the study of emotion comes from measures of peripheral physiology—pretty straightforward stuff like the size of your pupils, breathing rate, sweating, your heart rate. The most popular measures are in central brain physiology—functional MRI. These gauge local metabolic activity, in particular the local changes in blood oxidation.

The go-to methods for manipulating people's emotions in labs is to show them movie clips. Sometimes scientists also play music or ask people to remember something happy or sad. You can manipulate people's emotions with those techniques, but you can do it super fast and super strong with movie clips.

The caveat I'd add to that is there's an asymmetry. It's really easy with those methods to make people sad. You just show bad things happening to people, and viewers get sad. You can show people rainbows and puppies all day long, but it's very difficult to make people very happy. That's a grim part of the human condition that science hasn't fully explained.