When I was a Ph.D. student, my advisor told me a story about returning to his native Japan. As he walked into the elevator, he smiled at the employee operating the lift. In response, she gasped out loud and recoiled slightly. As my advisor told it, he reminded himself, "Oh yeah, when I'm in Japan I need to…" while he pulled his cheeks down into a slack expression.

His experience resonated with the six years I've lived in Mainland China. On one of my first trips to China, I remember smiling at a shopkeeper, who responded by furrowing her eyebrows. "I guess I shouldn't do that anymore," I thought to myself.

I was curious whether these casual observations were accurate—and whether they hinted at a deeper cultural difference—so I set out to test it systematically.

I trained research assistants in the United States and China how to systematically judge whether people were smiling or not. Then they stood at designated spots on university campuses and simply counted who was smiling and who wasn't. After observing 1,061 people, the differences we found surprised even me. As shown here, twice as many people were smiling on the American campus than on the Chinese campus.

Figure 1. Rates of smiling while people were walking outside in the US and China.

Figure 1. Rates of smiling while people were walking outside in the US and China.

When we analyzed factors such as weather, time of day, and even air pollution, we found these factors couldn't explain the differences between China and the U.S. For example, people were no more likely to be smiling on warm days versus cold days. The differences were also consistent regardless of which research assistant made the judgments.

However, coding smiles in the real world in real-time can be a challenge. To test whether we would also find these differences in smiling in a different context, we turned to a situation that gave the research assistants more time to make fine-grained determinations—school ID photos. Over 200 students at the University of Virginia gave us permission to rate their school ID photos for smiling.

Comparing student ID photos has the benefit of comparing people in the same environment. All students had their pictures taken in the same room in the same city with the same setup. The ID office also confirmed with us that they had no rules or instructions about smiling, so students could smile as much or as little as they wished.

Even though they were in exactly the same environment, the photographs showed that students from East Asia smiled less than students of European descent. The photographs also allowed us to separate so-called "true smiles" from fake smiles. Research has found that people perceive mouth smiles as less genuine than smiles that use the muscles around the eyes. (However, later research has found that some people can fake eye smiles too.)

Figure 2. In so-called

Figure 2. In so-called "true smiles," smilers use the muscles around the eye (AU6), which produces squinting and wrinkling around the eyes. Mouth smiling (AU12 and AU 25) is easier for people to fake. Image from Tsai et al., 2016.

Eye smiling was less common than mouth smiling across the board. Yet the cultural differences results were similar whether we looked at eye smiles or mouth smiles. Students from East Asia smiled less with both their eyes and their mouths.

Figure 3. In school ID photos, students from East Asia smiled less than students of European background. This difference held both in mouth smiling (left) and eye smiling (right).

Figure 3. In school ID photos, students from East Asia smiled less than students of European backgrounds. This difference held both in mouth smiling (left) and eye smiling (right).

Across two different contexts and methodologies — walking on campus and posing for ID photos — people in East Asia smiled less, but why? One hint might lie in loners. When we counted people walking outside, we noted whether they were walking alone or with other people. Not surprisingly, people were more likely to smile when they were with other people.

But the difference that struck me the most involved the people walking alone. Among people who were walking alone, roughly 35% of the Americans were smiling. Yet in China, almost no one who was walking alone was smiling.

Graph: Smiling in groups versus alone

In other words, smiling in China was limited to social interactions. In the U. S., smiling more often reflects an internal state—people having a good day or thinking of something nice that happened to them. In China, smiling was almost always contained in social interactions.

In line with this reasoning, researchers have found that Americans are more likely than people in other countries to interpret smiling as an indication of something internal, such as being in a good mood. In contrast, people in Japan are more likely to see smiling as serving a social function, such as wanting to sell you something or expressing embarrassment.

To be clear, complicated smiles are not just an East Asian phenomenon. Smiling doesn't always represent simple happiness in the U.S. either. For example, researchers in the West found that 96% of women who were asked an inappropriate question during a mock interview smiled in response.

Smiling sometimes serves a social communication function other than to indicate "I'm happy." It's just that this communication function appears to be more common in East Asia. That could explain why all those oddball Americans are smiling on their own.


For Further Reading

"Who smiles while alone? Rates of smiling lower in China than U.S."

Talhelm, T., Oishi, S., & Zhang, X. (2018). Who smiles while alone? Rates of smiling lower in China than U.S. Emotion, 19(4), 741–745.

Rychlowska, M., Miyamoto, Y., Matsumoto, D., Hess, U., Gilboa-Schechtman, E., Kamble, S., … Niedenthal, P. M. (2015). Heterogeneity of long-history migration explains cultural differences in reports of emotional expressivity and the functions of smiles. Proceedings of the National Academy of Sciences, 112(19), E2429–E2436.
 

Thomas Talhelm is an associate professor of behavioral science and William Ladany Faculty Scholar at the University of Chicago Booth School of Business.