Mirella Walker

Portraits made to measure: Manipulating social judgments about individuals with a statistical face model

The social judgments people make on the basis of the facial appearance of strangers strongly affect their behavior in different contexts. However, almost nothing is known about the physical information underlying these judgments. In this article, we present a new technology (a) to quantify the information in faces that is used for social judgments and (b) to manipulate the image of a human face in a way which is almost imperceptible but changes the personality traits ascribed to the depicted person. This method was developed in a high-dimensional face space by identifying vectors that capture maximum variability in judgments of personality traits. Our method of manipulating the salience of these vectors in faces was successfully transferred to novel photographs from an independent database. We evaluated this method by showing pairs of face photographs which differed only in the salience of one of six personality traits. Subjects were asked to decide which face was more extreme with respect to the trait in question. Results show that the image manipulation produced the intended attribution effect. All response accuracies were significantly above chance level. This approach to understanding and manipulating how a person is socially perceived could be useful in psychological research and could also be applied in advertising or the film industries.

Universals and Cultural Differences in Forming Personality Trait Judgments From Faces

Previous research has shown high cross-cultural consensus in personality trait judgments based on faces. However, the information that was provided in these studies included extrafacial features, such as hairstyle or clothes. Such styling information can be intentionally chosen by target persons to express who they are. Using a well-developed and validated Western face model, we were able to formalize the static facial information that is used to make certain personality trait judgments, namely, aggressiveness, extroversion, likeability, risk seeking, social skills, and trustworthiness judgments. We manipulated this information in photographs of Asian and Western faces with natural-looking results. Asian and Western participants identified the enhanced salience of all different personality traits in the faces. Asian participants, however, needed more time for this task. Moreover, faces with enhanced salience of aggressiveness, extroversion, social skills, and trustworthiness were better identified by Western than by Asian participants.

Caring or daring? Exploring the impact of facial masculinity/femininity and gender category information on first impressions.

In two studies we disentangled and systematically investigated the impact of subtle facial cues to masculinity/femininity and gender category information on first impressions. Participants judged the same unambiguously male and female target persons–either with masculine or feminine facial features slightly enhanced–regarding stereotypically masculine (i.e., competence) and feminine (i.e., warmth) personality traits. Results of both studies showed a strong effect of facial masculinity/femininity: Masculine-looking persons were seen as colder and more competent than feminine-looking persons. This effect of facial masculinity/femininity was not only found for typical (i.e., masculine-looking men and feminine-looking women) and atypical (i.e., masculine-looking women and feminine-looking men) category members; it was even found to be more pronounced for atypical than for typical category members. This finding reveals that comparing atypical members to the group prototype results in pronounced effects of facial masculinity/femininity. These contrast effects for atypical members predominate assimilation effects for typical members. Intriguingly, very subtle facial cues to masculinity/femininity strongly guide first impressions and may have more impact than the gender category.

The Basel Face Database: A validated set of photographs reflecting systematic differences in Big Two and Big Five personality dimensions

Upon a first encounter, individuals spontaneously associate faces with certain personality dimensions. Such first impressions can strongly impact judgments and decisions and may prove highly consequential. Researchers investigating the impact of facial information often rely on (a) real photographs that have been selected to vary on the dimension of interest, (b) morphed photographs, or (c) computer-generated faces (avatars). All three approaches have distinct advantages. Here we present the Basel Face Database, which combines these advantages. In particular, the Basel Face Database consists of real photographs that are subtly, but systematically manipulated to show variations in the perception of the Big Two and the Big Five personality dimensions. To this end, the information specific to each psychological dimension is isolated and modeled in new photographs. Two studies serve as systematic validation of the Basel Face Database. The Basel Face Database opens a new pathway for researchers across psychological disciplines to investigate effects of perceived personality.

Modelling perceptions of criminality and remorse from faces using a data-driven computational approach

ABSTRACT Perceptions of criminality and remorse are critical for legal decision-making. While faces perceived as criminal are more likely to be selected in police lineups and to receive guilty verdicts, faces perceived as remorseful are more likely to receive less severe punishment recommendations. To identify the information that makes a face appear criminal and/or remorseful, we successfully used two different data-driven computational approaches that led to convergent findings: one relying on the use of computer-generated faces, and the other on photographs of people. In addition to visualising and validating the perceived looks of criminality and remorse, we report correlations with earlier face models of dominance, threat, trustworthiness, masculinity/femininity, and sadness. The new face models of criminal and remorseful appearance contribute to our understanding of perceived criminality and remorse. They can be used to study the effects of perceived criminality and remorse on decision-making; research that can ultimately inform legal policies.

The conceptual structure of face impressions

Significance Current theory of face-based trait impressions focuses on their foundation in facial morphology, from which emerges a correlation structure of face impressions due to shared feature dependence, “face trait space.” Here, we proposed that perceivers’ lay conceptual beliefs about how personality traits correlate structure their face impressions. We demonstrate that “conceptual trait space” explains a substantial portion of variance in face trait space. Further, we find that perceivers who believe any set of personality traits (e.g., trustworthiness, intelligence) is more correlated in others use more similar facial features when making impressions of those traits. These findings suggest lay conceptual beliefs about personality play a crucial role in face-based trait impressions and may underlie both their similarities and differences across perceivers. Humans seamlessly infer the expanse of personality traits from others’ facial appearance. These facial impressions are highly intercorrelated within a structure known as “face trait space.” Research has extensively documented the facial features that underlie face impressions, thus outlining a bottom-up fixed architecture of face impressions, which cannot account for important ways impressions vary across perceivers. Classic theory in impression formation emphasized that perceivers use their lay conceptual beliefs about how personality traits correlate to form initial trait impressions, for instance, where trustworthiness of a target may inform impressions of their intelligence to the extent one believes the two traits are related. This considered, we explore the possibility that this lay “conceptual trait space”—how perceivers believe personality traits correlate in others—plays a role in face impressions, tethering face impressions to one another, thus shaping face trait space. In study 1, we found that conceptual and face trait space explain considerable variance in each other. In study 2, we found that participants with stronger conceptual associations between two traits judged those traits more similarly in faces. Importantly, using a face image classification task, we found in study 3 that participants with stronger conceptual associations between two traits used more similar facial features to make those two face trait impressions. Together, these findings suggest lay beliefs of how personality traits correlate may underlie trait impressions, and thus face trait space. This implies face impressions are not only derived bottom up from facial features, but also shaped by our conceptual beliefs.