As Westerners, we tend to rely on facial appearance to make an initial judgment about someone, especially a judgment of trust. Our first impression of a person is thus formed from the physical characteristics of their face. The existence of a social consensus in the judgments made about individuals sharing certain facial features suggests that, when perceived by different observers, these features lead fairly systematically to similar judgments (Melissa Carré, 2021).
A reflex impossible to inhibit
When we first meet someone, we are first exposed to a new face. The perception of its different aspects quickly contributes to the formation of our first impression. The latter occurs automatically, without us being aware of it or being able to inhibit it.
It is in fact a reflex, i.e. we do not have to make any cognitive effort. This first impression can then be used as a heuristic (or cognitive shortcut) to judge the trustworthiness of the person and to answer complex questions, such as those asked by an evaluator during a job interview.
What the research says
Faces, and particularly the information they convey, have attracted the attention of early studies in psychology, whether it be on the detection of emotions or the deduction of personality traits.
Although current research recognizes that the face is a vehicle for emotions, it does not consider that it reflects personality. Instead, researchers focus on the mechanisms that lead us to make judgments based on the face. They are thus interested in what we call "impression formation".
The work of Nikolaas N. Oosterhof and Alexander Todorov in 2008 informs us about the first impression based on the face of our interlocutor.
In their work, these researchers first identified and catalogued a wide variety of psychological traits spontaneously used to categorize emotionally neutral faces, such as attractiveness, sociability, aggressiveness, and dominance, to mention a few.
They then subjected these judgments to a principal component analysis. In doing so, the researchers demonstrated that social judgments can be grouped under two orthogonal dimensions:
· Emotional valence, which is the ability to perceive the positive or negative character of our emotional state from our face, and more particularly from our smile;
· dominance, which would be associated with masculine features and facial maturity associated with facial aging.
Figure 1: Examples of faces with neutral expressions.
Examples of trait-based judgments
It would be difficult to provide an exhaustive list of possible variations in facial features in individuals adopting a neutral expression. However, it can be seen that the shape of the mouth has a strong impact on the trustworthiness of a person: the more trustworthy the face is perceived to be, the more the line between the lips appears to be U-shaped, and vice versa. This characteristic associated with a trustworthy face is reminiscent of the curve in a person's face when smiling. It is therefore possible to think that we perceive the reliable face as that of a happy person.
The assumption that a happy person is a reliable person is, of course, a generalization. It is because certain facial features (e.g., the U-shaped lip line) evoke universal emotional expressions (such as the smile of a happy person) that this type of generalization takes place and colors our judgment. We unconsciously judge that if a person is happy, he or she must be likeable and therefore trustworthy, which of course is not always true!
Other examples of facial features influencing trust judgments about a person at the first impression stage were given by the researchers:
- The closer the features were to an angry expression, the more untrustworthy (or dominant) the face was perceived by observers.
- As the distance between the eyes and the eyebrows increased, the facial features became more baby-like, and thus were perceived by observers as those of a trustworthy person.
In general, there is a social consensus that most observers perceive the expression of anger on a face as inversely proportional to the degree of trustworthiness. In other words, the face on the right in Figure 1 would likely be perceived as that of an unreliable person. Conversely, the more happy a face looks, the more likely it is to be categorized as trustworthy. This would be the case, for example, with the face on the left in Figure 1; most observers' judgment of the person to whom it belongs would likely be positive.
What is the lesson to be learned from this?
When we look at a face, we can extract different types of information that tell us about the person and his or her situation (e.g., age class, membership in a population group, or emotional state). This ability to detect and interpret information from the face is innate and develops throughout life. This is why children are particularly interested in the faces of adults, and adolescents and adults are better able to interpret the faces of their peers.
What is extremely interesting is the consistency of our judgments observed in the study by Oosterhof and Todorov . In fact, almost everyone denotes the same characteristics in a face and associates the same judgment to it.
Carré (2021) points out that "contrary to the recommendation in the phrase 'you shouldn't judge a book by its cover', most of us quickly and effortlessly infer personality traits based solely on facial appearance" (Bar et al., 2006; Walker & Vetter, 2009; Willis & Todorov, 2006). In other words, every encounter we have is likely to be colored by the unconscious cognitive bias of first impressions.
Confidence judgment represents one of the main dimensions of social judgments made on the basis of a first impression, as it can explain more than half of the total variance in evaluations made from faces (Oosterhof & Todorov, 2008).
In a recruitment context, this can have a direct impact on the confidence you have in a candidate during a first interview. Be wary of your first impression, or at least learn to minimize it. By being aware of this possible cognitive bias in your selection process, you will ensure that you give every face you meet a chance, regardless of its features.
 Oosterhof, Nikolaas N. and Alexander Todorov (2008). The functional basis of face evaluation. Proceedings of The National Academy of Sciences, 105(32), 11087-11092.