A paradoxical finding from recent studies of face perception is that observers are error-prone and inconsistent when judging the identity of unfamiliar faces, but nevertheless reasonably consistent when judging traits. Our aim is to understand this difference. Using everyday ambient images of faces, we show that visual image statistics can predict observers' consensual impressions of trustworthiness, attractiveness and dominance, which represent key dimensions of evaluation in leading theoretical accounts of trait judgement. In Study 1, image statistics derived from ambient images of multiple face identities were able to account for 51% of the variance in consensual impressions of entirely novel ambient images. Shape properties were more effective predictors than surface properties, but a combination of both achieved the best results. In Study 2 and Study 3, statistics derived from multiple images of a particular face achieved the best generalisation to new images of that face, but there was nonetheless significant generalisation between images of the faces of different individuals. Hence, whereas idiosyncratic variability across different images of the same face is sufficient to cause substantial problems in judging the identities of unfamiliar faces, there are consistencies between faces which are sufficient to support (to some extent) consensual trait judgements. Furthermore, much of this consistency can be captured in simple operational models based on image statistics. Facial impressions 3 Facial impressions 4 surprisingly wide range of performance across different observers in the normal population (Burton, White & McNeill, 2010). By analysing the statistical properties of ambient images of faces, Burton, Kramer, Ritchie and Jenkins (2016) showed that image variability is to some extent idiosyncratic-that is, the ways in which one person's face varies across images can be different for someone else's face. Learning to recognise a familiar face thus involves learning how that face can vary, through seeing it in many settings-in effect becoming sufficiently expert with that face identity to be able to recognise new photos of the same person. But this form of perceptual expertise is identity-specific and may not generalise to another person's face, because that face varies in different ways. For this reason, unfamiliar face recognition is often poor because the range of variability of an unfamiliar face is unknown (Burton et al., 2016; Kramer, Young & Burton, 2018; Young & Burton, 2018). Computational work has shown the utility of this approach by simulating a range of well-known properties of familiar and unfamiliar face recognition (Kramer, Young, Day & Burton, 2017; Kramer et al., 2018). Although perception of the identities of unfamiliar faces can be problematic, many other characteristics are more easily seen. These include relatively objective properties determined by structural cues such as apparent gender, age and ethnicity (Bruce & Young, 2012) and more subjective impressions of social dispositions su...