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Neuroscience
The Complexities of Human Smiles
Recent research sheds interesting light on smile interpretation.
Posted August 30, 2021 Reviewed by Davia Sills
Key points
- Americans smile twice as much as East Asians do, research has found.
- American students are also more likely to smile while alone than are East Asian students.
- People seek an unexpected smile despite related financial loss, and this is paired with distinct neural patterns.
- Children and adults are more likely to remember a person who displays incongruence between expression and expected behavior.
You are likely familiar with the expression that a smile is “just a frown turned upside down.” But this platitude belies the nuanced nature of smiling. The complexity of smiling is likely reflected in the number of synonyms for different types of smiles (e.g., beam, simper, smirk, and leer).
Let’s take a look at some recent research on smiles.
Cultural Differences
In results from a 2018 study available via SSRN, researchers compared rates of smiling in European American students with those of Chinese students. The investigators found that Americans smiled twice as much as East Asian students in ID photos (40.4 percent vs. 20.2 percent), with the former slightly more likely to display “excited” smiles. Rates of “calm” smiles were the same in both groups.
The authors also found that in real-time, students at U.S. universities were more likely than their Chinese counterparts to smile while walking on campus. Intriguingly, 3 percent of Chinese students walking alone smiled, whereas 29.1 percent of American students were observed doing so.
“One explanation for these differences is that smiling reflects base rates of happiness in China and the U.S. Studies have found higher life satisfaction in the U.S. than in China. Perhaps people in China smile less because they’re less happy,” wrote the authors.
“Another explanation is that the differences reflect differences in ideal affect. If Americans value high-intensity positive emotions, that could explain why they are more likely to smile,” they added.
Social Decision-Making
The ultimatum game is a frequently used research tool in the investigation of human decision-making. During this task, one party is the “prosperer” and divides an amount of money to share with the “responder.” The responder can then accept or reject the offer. If accepted by the responder, the money is divided as proposed by the proposer. If not, no money is distributed. Most people would expect that half the amount of money, or 50 cents on the dollar, is fair. An offer of 10 cents, on the other hand, would be considered unfair.
In a 2020 study published in Cognitive, Affective, and Behavioral Neuroscience, researchers used the ultimatum game to test the influence of socially unexpected feedback, or smiling in reaction to a rejected offer in the ultimatum game, on behavioral and neural responses.
The investigators found that identities who reacted with a smile toward rejected offers elicited lower acceptance rates versus those who rewarded acceptance with a smile. Electrophysiologic tests involving brain potentials supported these findings.
“To sum up, we were able to show that positive feedback does not necessarily have to be interpreted as such, and by social framing, it could have different meanings, such as a friendly apology,” the authors wrote. “Hence, individuals seek an unexpected smile despite the associated monetary loss, which is accompanied by distinct neural patterns.”
Facial Recall
As demonstrated in the aforementioned study, smiling after rejecting an offer is an example of emotional incongruity that adversely affects social interactions. Emotional incongruity can also impact facial recall, as demonstrated by the results of a 2019 study published in the Journal of Experimental Child Psychology.
Researchers assessed how well children aged 5 or 6 years remembered smiling or angry phases based on social cues. Children obtained coins that could be traded in for stickers (i.e., rewards) after answering quiz questions. The children then took part in a coin-collection game in which individual persons with smiling or angry expressions either gave or took coins from the child participants in congruent (i.e., smiling giver/angry taker) or incongruent (i.e., angry giver/smiling taker) fashions.
During later tests of facial recall, children were significantly more likely to recognize incongruent instances involving smiling takers versus angry takers. No differences in recall, however, were observed involving smiling and angry givers. These patterns of child recall reflect those of adults, with adults more likely to remember a person who demonstrates incongruence between expression and expected behavior (e.g., smiling while stealing).
“Remembering whether a person is cooperative is essential in social interactions,” wrote the authors. “The findings lead to implications and further questions for integrating evolutionary and proximate explanations of the memory advantage for threatening others, in particular—the ‘smiling enemies.’”
Bottom Line
Findings from an emerging corpus of studies demonstrate the expectations people have with regard to smiles, as well as how smiles are interpreted cross-culturally. In the aggregate, the power of a smile should not be underestimated in social interactions and as a form of social currency.
