Individual Differences in Person Perception
As a behavioral researcher who started his career as a clinical psychologist, I have always been fascinated by individual differences in various faculties of the human mind. In my current research, I focus on the impact of the perceiver factors (e.g., stereotypes) and the impact of new information (e.g., new experiences) on social perception. A stronger emphasis on these conceptual (vs. perceptual) components of social processing naturally pushes me to investigate individual differences; the level and types of stereotypes and information gathered via life experiences vary across perceivers (whereas perceptual information from others’ faces for example, is identical across all perceivers). Investigating individual differences is valuable because it sheds a light on how a psychological phenomenon works. In my research, I have identified several domains of social perception in which individual differences substantially affect the way we perceive others: Individual differences in (1) gender stereotypes, (2) age, and (3) personality preferences.
The simplification of impressions (or lower level of differentiations across impressions) was more severe for those who strongly believed gender stereotypes, both for male and female faces. For example, if you are a person who strongly believes that ‘women are on average emotional, nurturing, etc. than men and that men are on average competitive, aggressive, etc. than women’, you are more likely to form a more simplified impressions of women and men than those who hold weaker gender stereotypes. Sexism at the level of faces (i.e., individuals whose look do not conform to gender norms are punished, economically and socially) is harsher, when the perceiver has stronger gender stereotypes. These findings show that it is essential to consider individual differences in the role of stereotypes in social perception.
Individual Differences in Stereotypes
Stronger stereotypes simplify your impressions of others from faces. My colleagues and I have found that people form more simplified (less differentiated) impressions of women than of men (Oh et al., 2019 Psychol Sci; Oh et al., 2019 J Exp Psychol: Gen). Impressions of women are more highly intercorrelated than those of men; people believed that on average for example, impressions of likability and dominance for women were more strongly negatively related to each other, compared to those of vs. men, in people’s minds. The simplification of impressions (or lower level of differentiations across impressions) was more severe for those who strongly believed gender stereotypes, both for male and female faces. For example, if you are a person who strongly believes that ‘women are on average emotional, nurturing, etc. than men and that men are on average competitive, aggressive, etc. than women’, you are more likely to form a more simplified impressions of women and men than those who hold weaker gender stereotypes. Sexism at the level of faces (i.e., individuals whose look do not conform to gender norms are punished, economically and socially) is harsher, when the perceiver has stronger gender stereotypes. These findings show that it is essential to consider individual differences in the role of stereotypes in social perception.

The level of impression simplification (how different individual impressions were differentiated, e.g., between ‘trustworthy’ impressions and ‘unhappy’ impressions, were predicted by participants’ level of gender stereotype endorsement. The more one endorsed the gender stereotypes (”women are on average more emotional than men are”), the more simplified their face-based impressions for others were. (from Oh et al. 2020 J Exp Psychol: Gen)
Individual Differences in Age
My colleagues and I previously found that individuals were perceived as more competent when their faces were paired with “expensive” clothes (Oh et al., 2019 Nat Hum Behav). Despite the subtlety in our manipulation, the effect was hard to control, surviving various countermeasures we coined (e.g., instructions to ignore the clothes, and the promise of a reward (100 US dollars) for the most “accurate” response that ignored the clothes).
In addition to this main finding, we also found the effects of participant age. We found two things: (1) Regardless of the types of attire paired with the faces (“richer” or “poorer”), older participants reported higher competence impressions (i.e., rated other individuals more favorably) than did younger participants; (2) interestingly, older participants showed smaller differences between their competence ratings of “richer” vs. “poorer” images than younger participants did. Put differently, older participants were more generous in competence judgments; and not only that, older participants were more “immune” to the status-cue effects in competence impressions than younger participants.

Older participants rated other individuals as more competent than did younger participants. Older participants also showed smaller differences between their competence ratings of “richer” and “poorer” images than younger participants did. (from
Oh
et al. 2020 Nat Hum Behav)
Individual Differences in Personality Preference
In an industrialized society (like the US), women find male faces with feminine shape (e.g., bigger eyes, narrower chin) more attractive, compared to faces with masculine shapes. My colleagues and I found that this may be because women’s prefer feminine (vs. masculine) personality in a partner: warmth, nurturingness, and gentleness (Oh et al., 2020 J Exp Pscyhol: Hum Percept Perform). In addition to this general principle (feminine personality preference → feminine face-shape preference), we also found a finding specific to individual perceivers: Those who preferred feminine personality traits in a partner preferred feminine characteristics in male faces, whereas those who preferred masculine personality traits (even though they were in minority) preferred masculine characteristics in male faces. This finding explains the rich diversity in attractiveness perception and mating choice. At the same time, it highlights that we should consider conceptual factors when we think about interpersonal attraction, in addition to perceptual factors (e.g., facial symmetry, which contributes to attractiveness).

Individual participants’ personality preferences predicted what type of facial judgments predicted their perceptions of attractiveness of faces. In other words, when a person prefers a specific trait such as dominance, faces that appear dominant are likely to appear attractive to them.
a: The positive effect of feminine trait judgments on attractiveness was stronger among those who preferred a feminine personality than among those who preferred a masculine personality, although the difference did not reach significance
b: The positive effect of masculine trait judgments on attractiveness was stronger among those who preferred a masculine personality than among those who preferred a feminine personality. (from Oh et al. 2020 J Exp Psychol Hum Percept Perform)