How do people determine trustworthiness in others?
While research has shown that smiling faces are generally trusted more than non-smiling ones, the perception of trustworthiness varies significantly across cultures.
We discussed this in last week’s blog, which examined cross-cultural research that delved into the complex and varied interpretations of smiling.
Yet another study on the subject seems to confirm that research.
Exploring the “smile effect” in American and Japanese participants, this study focuses on how different elements of a smile – intensity at the eyes, intensity at the mouth, and facial symmetry – influence judgments of trustworthiness.
Let’s dive in.
Cultural Variations in Smile Perception
Researchers initially had Japanese participants rate 54 American and 69 Japanese male faces for smile intensity at the eyes and mouth, as well as facial symmetry.
These images were then presented to 142 American and 80 Japanese participants, who rated each face’s trustworthiness.
The findings revealed stark cultural differences.
Japanese participants found faces with greater upper-half (eye) intensity and smile symmetry to be more trustworthy but viewed faces with greater lower-half (mouth) intensity as less trustworthy.
Conversely, American participants perceived faces with greater lower-half intensity as more trustworthy, while upper-half intensity and smile symmetry had no significant impact.
Understanding These Differences
Why do these cultural differences occur?
The study suggests that in Japanese culture, people tend to control their emotional expressions, relying more on the eyes and smile symmetry, which are harder to manipulate, to judge trustworthiness.
Additionally, in Japan, highly expressive smiles are less appropriate in cooperative contexts, leading to a lower trust rating for strongly smiling faces.
In contrast, American culture encourages overt emotional expression.
Therefore, American participants focused more on the mouth, the most expressive part of the face, when making trust judgments.
Additional Findings
The study also examined other personality traits and found a variety of cultural differences and similarities.
Interestingly, American faces were rated by Japanese participants as more trustworthy than Japanese ones, while Japanese faces were rated by American participants as more trustworthy than American ones.
This suggests that cultural biases can influence perceptions of trustworthiness.
The study had several limitations.
The three smile elements were rated only by Japanese participants, and these ratings may differ across cultures.
The photographs used were taken for electoral campaigning, which might not reflect everyday expressions.
Furthermore, only male faces were used, so future studies should include female faces to see if the findings apply across genders.
Smile Trustworthiness
This study highlights significant cultural differences in how trustworthiness is inferred from smiles.
To fully understand the detection of trustworthiness, future research should explore how people express their intentions and emotions when they have an incentive to be trusted, considering both the receivers and senders of facial signals.
Additionally, understanding the historical context and origins of these cultural differences would provide a deeper insight into the mechanisms of nonverbal communication, which becomes more important as the world becomes more globally connected.
Success Across Cultures 