Perspective distortion from interpersonal distance is an implicit visual cue for social judgments of faces

Abstract

The basis on which people make social judgments from the image of a face remains an important open problem in fields ranging from psychology to neuroscience and economics. Multiple cues from facial appearance influence the judgments that viewers make. Here we investigate the contribution of a novel cue: the change in appearance due to the perspective distortion that results from viewing distance. We found that photographs of faces taken from within personal space elicit lower investments in an economic trust game, and lower ratings of social traits (such as trustworthiness, competence, and attractiveness), compared to photographs taken from a greater distance. The effect was replicated across multiple studies that controlled for facial image size, facial expression and lighting, and was not explained by face width-to-height ratio, explicit knowledge of the camera distance, or whether the faces are perceived as typical. These results demonstrate a novel facial cue influencing a range of social judgments as a function of interpersonal distance, an effect that may be processed implicitly.

Figure 1. Perspective distortion from distance influences trust (Experiment 1a and Experiment 2).

Histograms show investment difference (far-close) for each face, averaged over all participants. A disproportionately larger number of faces received a positive investment difference (light bars) compared to those receiving a negative investment difference (dark bars).

Figure 2. Social judgments as a function of perspective distortion (Experiment 3a), verbal information (Experiment 3b), and image size (Experiment 3c).

In each Experiment, ratings were obtained for Trust (solid black bars), Competence (gray bars), and Attractiveness (white bars). The mean Far-Close score over all participants and stimulus faces is shown on the y-axis (with the error bar indicating the 95% confidence interval).

Figure 3. Additional social judgments from perspective distortion (Experiment 3d–e).

Shown are means and 95% CI for ratings of Heaviness, Age, Distance to Camera (Experiment 3d), Averageness (Experiment 3e).

Figure 4. Creation of stimuli.

The schematic illustrates how the two photographs of a face were taken at two distances simultaneously, and summarizes the post-processing steps to equate the resultant images and generate the stimuli.