Changes in Person Impressions

One line of my work is focused on understanding continuous update in social perception, with information provided by new experiences. This update allows people to adapt to the ever-changing environment. This line of research shows that impressions of other individuals often drastically yet reliably change after the initial judgments, affecting various aspects of our perception and memory, including the facial identity perception and personality impressions. My research aims to identify the underlying forces behind people’s evolving perception of others.

Although superficial information such as facial features and social biases contributes to initial social judgments, various factors color the initial input at later stages. To dissect the complex, multi-staged process of social impression formation, I use techniques such as mouse-tracking, reverse correlation, continuous rating, and multivariate pattern analysis. In my research, I have identified the role of knowledge in different stages of dynamic impression updating, ranging from facial identity recognition to trait judgments about other individuals.

Changes in Face Identity Perception

Newly learned person knowledge shapes the way we recognize faces (Oh et al. 2021 Cognition). My colleagues and I first found that when a perceiver believed that two famous individuals’ personalities were similar, their faces were perceived to be similar, above and beyond their actual physical facial similarity, as revealed by hand-motion trajectories in face-to-name and face-to-face perceptual-match tasks. Correspondingly, when a perceiver believed that two individuals were similar, the perceptual representations of their faces were similar, as revealed by a reverse-correlational technique. 

Moreover, the effect persisted when perceivers learned about novel faces randomly linked to specific personality traits (e.g., trustworthiness): When any two individuals were presented as having more similar personalities – independent of their physical facial similarity – their faces were perceived as more similar. These findings suggest that the link between person knowledge and facial identity perception is causal in nature, providing evidence that even facial individuation – a seemingly rudimentary perceptual process – is influenced by novel social knowledge. At the same time, these findings highlight the need to consider how new information is integrated after the initial judgments, so as to gain a more complete understanding of social impressions.

Knowledge of a person’s personality can bias perception of a face’s identity toward an alternate identity that is not ostensibly related. For example, if Vladimir Putin and Justin Bieber (above) have more similar personalities in your mind, then they visually appear more similar to you as well. Further, when you learn two novel individuals are similar in their personalities (below), you remember their faces as more similar to each other (compared to when you learn the two individuals were dissimilar in their personalities). (from Oh et al., 2021 Cognition)

Changes in Personality Trait Impressions 

People’s impressions of others’ personalities can be reliably tracked over time and systemically explained. My colleagues and I are working to identify the computational and neural basis of real-time social perception. To collect data, participants in an MRI scanner, without an explicit task, viewed a film in which various characters naturally interacted with one another. A separate group of participants watched the same video and continuously rated a trait of one of the characters (e.g., friendliness) in real time. Preliminary analyses indicated that (1) the perceivers considerably changed their impressions of each character as they learned more about these individuals during the continuous real-time trait rating; (2) nonetheless, there was a high level of consensus across perceivers in how they changed their impressions of the character over time; and (3) the impressions of each character were tracked in multiple brain regions. These findings suggest that we need to consider both how impressions of others are initially formed and how new information about them is continuously integrated over time. A novel framework is needed to consider the meaningful real-time changes in impressions.

Using a continuous rating paradigm, participants altered their trait judgments over time as they watch naturalistic interactions between other individuals. Participants considerably changed their impressions of each character as they learned more about these individuals, but there was a high level of consensus across participants in how they changed their impressions of each character over time. The impressions of each character were tracked in multiple brain regions.