Smiles serve as a window into personality, providing others with the opportunity to see through. 

Smiles do more than just express emotion— when posed in photographs, they offer a glimpse into our personalities. In today's world, where we often share our smiles through social media, professional profiles, and dating apps, understanding what our smiles convey is more important than ever. Not all smiles are the same, and subtle variations can reveal a lot about who we are.

One particular type of smile, the Duchenne smile, involves the simultaneous activation of two muscles: the Zygomatic Major, which lifts the corners of the mouth, and the Orbicularis Oculi, which creates wrinkles at the lateral corners of the eyes. Traditionally, Duchenne smiles were thought to only occur with spontaneous happiness experiences. However, my research suggests that these smiles emerge when posing a smile, and reveal key aspects of a person's personality.

Research Overview

To explore this, we conducted two studies:

  • Study 1: We photographed 303 participants, capturing both neutral and smiling expressions. We also assessed their personality traits, focusing on warmth, trustworthiness, aggression, conscientiousness, and hubris. Using the Facial Action Coding System (FACS), we analyzed their smiles, particularly looking for the Duchenne smile.

  • Study 2: We asked 987 participants to evaluate the personality traits of the individuals in the photographs from Study 1. They rated the subjects on the same traits we assessed earlier.

Key Findings

The results showed that people who are warmer, more trustworthy, and more conscientious, or less aggressive and hubristic, are more likely to pose with Duchenne smiles when spontaneously smiling for a photograph. When others viewed these smiles, they were able to make accurate judgments about the person's personality for each of these traits. In fact, the accuracy of these judgments was linked directly to the observing Duchenne smiles.

Additionally, observers made slightly more accurate personality assessments from smiling photos compared to neutral ones. This suggests that our smiles, especially Duchenne smiles, serve as a reliable indicator of our personality traits, helping others form more accurate impressions of us.

In summary, a posed smile is more than just an expression—it's a reflection of your personality that others can read and interpret, perhaps more accurately than we might expect.

 
 

Discussion

Taken together, posed smiles (especially Duchenne smiles) reveal key personality traits including trustworthiness, warmth, conscientiousness, aggression, and hubris, allowing observers to form accurate judgments about a person based on their simple smile. These insights carry significant implications, both for society and for the scientific understanding of nonverbal communication.

Societal implications: The good, the bad, and the ugly

In today’s digital age, where smiling photographs are frequently shared on platforms like Facebook, Instagram, and LinkedIn, this research raises important privacy concerns. Our smiling images might reveal more about our personalities than we intend, potentially exposing us to unintended personality signaling or even privacy violations. Given that many social networking sites require profile pictures to be publicly accessible, the risk of inadvertently sharing personal information through our smiles is heightened.

However, this transparency isn’t necessarily a negative thing. On the positive side, showcasing our personality through a smile may help us connect with more compatible partners on virtual dating platforms, or authentically present ourselves as being the right fit for a job. In these cases, our smiles can act as a powerful and honest tool in social and professional interactions.

Read the full paper here.