Both facial width-to-height ratio (fWHR) and body mass index (BMI) have been associated with aggressive behavior in women but how they influence perception of their potential threat remain unclear. Here, we assessed the effects of fWHR and BMI on perceived formidability from faces of 42 female Ultimate Fighting Championship (UFC) fighters. In study 1, BMI, but not fWHR, positively predicted participants' ratings of aggressiveness and fighting ability from facial photographs. In study 2, both high fWHR and high BMI composite faces were rated as more aggressive, tougher, and more likely to win a fight than low fWHR and low BMI composite faces, respectively. Further analyses revealed that the high BMI composite face was rated as more aggressive and tougher than the high fWHR composite face. Taken together, these results suggest that compared to fWHR, BMI may be a more salient cue to women's formidability.

First impressions of traits are formed rapidly and nonconsciously, suggesting an automatic process. We examined whether first impressions of trustworthiness are mandatory, another component of automaticity in face processing. In Experiment 1a, participants rated faces displaying subtle happy, subtle angry, and neutral expressions on trustworthiness. Happy faces were rated as more trustworthy than neutral faces; angry faces were rated as less trustworthy. In Experiment 1b, participants learned eight identities, half showing subtle happy and half showing subtle angry expressions. They then rated neutral images of these same identities (plus four novel neutral faces) on trustworthiness. Multilevel modeling analyses showed that identities previously shown with subtle expressions of happiness were rated as more trustworthy than novel identities. There was no effect of previously seen subtle angry expressions on ratings of trustworthiness. Mandatory first impressions based on subtle facial expressions were also reflected in two ratings designed to assess real-world outcomes. Participants indicated that they were more likely to vote for identities that had posed happy expressions and more likely to loan them money. These findings demonstrate that first impressions of trustworthiness based on previously seen subtle happy, but not angry, expressions are mandatory and are likely to have behavioral consequences.

First impressions based on facial cues have the potential to influence how older adults (OAs), a vulnerable population, are treated by others. The present study used a data-driven approach to examine dimensions underlying first impressions of OAs and whether those dimensions vary by perceiver age. In Experiment 1, young adult (YA) and OA participants provided unconstrained, written descriptions in response to OA faces. From these descriptors, 18 trait categories were identified that were similar, but not identical, across age groups. In Experiment 2, YA and OA participants rated OA faces on the trait words identified for their age group in Experiment 1. In separate principal components analyses, dimensions of sternness and confidence emerged for both groups. In Experiment 3, YA and OA participants rated these same faces on new words encompassing traits, emotion cues, and other appearance cues. Correlations between these ratings and factor scores showed that sternness is analogous to approachability for both age groups. Confidence is analogous to competence for both age groups and related to perceived age/health/attractiveness. Confidence was related to shyness for YAs but dominance for OAs. The current research has implications for a lifespan perspective on first impressions and informs functional accounts.

Considering the widespread use of face masks during the COVID-19 pandemic, the goal of the current study was to examine how occlusion of the lower half of the face may impact first impression formation. We conducted three experiments, each building on previous research, investigating the effect of face masks on first impressions of faces across the lifespan (children, young and older adults). Experiment 1 examined whether the mandatory influence of happy facial expressions on perceived trustworthiness in young adult faces is influenced by face masks. Experiment 2 examined behavioural consequences of adults’ first impressions of child faces to determine whether masks reduce the effect of facial niceness on interpretations of ambiguous behaviour. Experiment 3 investigated consensus for first impressions of trustworthiness and competence in older adult faces with and without masks, as well as consensus on underlying facial cues. The results of all three experiments present converging evidence that masks do not have a significant impact on first impressions and their behavioural consequences.

Sutherland and Young's perspective is a timely and rigorous examination of trait impressions based on facial cues. We propose three strtegies to further advance the field: incorporating natural language processing, including diverse facial stimuli, and re-interpreting developmental data.