Accuracy in Facial Trustworthiness Impressions: Kernel of Truth or Modern Physiognomy? A Meta-Analysis

Abstract

Being able to identify trustworthy strangers is a critical social skill. However, whether such impressions are accurate is debatable. Critically, the field currently lacks a quantitative summary of the evidence. To address this gap, we conducted two meta-analyses. We tested whether there is a correlation between perceived and actual trustworthiness across faces, and whether perceivers show above-chance accuracy at assessing trustworthiness. Both meta-analyses revealed significant, modest accuracy (face level, r = .14; perceiver level, r = .27). Perceiver-level effects depended on domain, with aggressiveness and sexual unfaithfulness having stronger effects than agreeableness, criminality, financial reciprocity, and honesty. We also applied research weaving to map the literature, revealing potential biases, including a preponderance of Western studies, a lack of “cross-talk” between research groups, and clarity issues. Overall, this modest accuracy is unlikely to be of practical utility. Moreover, we strongly urge the field to improve reporting standards and generalizability of the results.

Understanding trait impressions from faces

“…Given that facial impressions have reasonably low validity (in the sense that a given individual who looks trustworthy may not be trustworthy, Foo et al, 2021), why do we persist in forming and acting on them 2020), Nature Human Behaviour so readily? Theories of first impressions suggest the reason is that impression formation is nonetheless functional; we form impressions because we seek to predict our social interactions (Fiske et al, 2007;Oosterhof & Todorov, 2008;Sutherland et al, 2018;Zebrowitz, 2005).…”

“…Many studies have shown that people tend to agree on their impressions and that impressions from faces are formed readily (Klapper et al, 2016; Oosterhof & Todorov, 2008), implicitly (Swe et al, 2020) and with minimal information; even a single glimpse of a photograph can suffice (Willis & Todorov, 2006). Impressions of traits from faces have at best only limited accuracy, meaning that their everyday use is problematic (Foo et al, 2021). Yet, despite this limited accuracy, facial impressions often have critical social consequences.…”

“…Theories of first impressions suggest the reason is that impression formation is nonetheless functional; we form impressions because we seek to predict our social interactions (Fiske et al, 2007; Oosterhof & Todorov, 2008; Sutherland et al, 2018; Zebrowitz, 2005). Moreover, impressions may have enough of a kernel of truth, or at least overlap with other, more accurate judgements, to allow them to persist at a population level even with low overall accuracy (Foo et al, 2021).…”

“…witnessing masculine men being more aggressive). Of course, ecology likely cannot explain how all impressions are learnt from the surrounding environment, given that, as already noted, the accuracy of impressions tends to be low (Foo et al, 2021; Todorov et al, 2015). Nevertheless, a careful unpacking of which cross‐cultural variables predict different impression mechanisms will greatly help the field move beyond simplistic dichotomies.…”

“…et al, 2020) and with minimal information; even a single glimpse of a photograph can suffice (Willis & Todorov, 2006). Impressions of traits from faces have at best only limited accuracy, meaning that their everyday use is problematic (Foo et al, 2021). Yet, despite this limited accuracy, facial impressions often have critical social consequences.…”