Judging trustworthiness from faces: Emotion cues modulate trustworthiness judgments in young children

By adulthood, people judge trustworthiness from appearances rapidly and reliably. However, we know little about these judgments in children. This novel study investigates the developmental trajectory of explicit trust judgments from faces, and the contribution made by emotion cues across age groups. Five‐, 7‐, 10‐year‐olds, and adults rated the trustworthiness of trustworthy and untrustworthy faces with neutral expressions. The same participants also rated faces displaying overt happy and angry expressions, allowing us to investigate whether emotion cues modulate trustworthiness judgments similarly in children and adults. Results revealed that the ability to evaluate the trustworthiness of faces emerges in childhood, but may not be adult like until 10 years of age. Moreover, we show that emotion cues modulate trust judgments in young children, as well as adults. Anger cues diminished the appearance of trustworthiness for participants from 5 years of age and happy cues increased it, although this effect did not consistently emerge until later in childhood, that is, 10 years of age. These associations also extended to more subtle emotion cues present in neutral faces. Our results indicate that young children are sensitive to facial trustworthiness, and suggest that similar expression cues modulate these judgments in children and adults.     

Seeing or smelling? Assessing personality on the basis of different stimuli

This study examines whether people can accurately assess personality on the basis of facial images and body odor and whether attractiveness influences these relationships. Three personality dimensions of target individuals – neuroticism, extraversion and dominance – were measured with the NEO Five-Factor Inventory, a one-item measure of dominance and the reports of close acquaintances. Naive observers assessed neuroticism and dominance at above-chance levels based on body odor, and they assessed extraversion (and in some cases, neuroticism) at above-chance levels based on either facial images alone or body odor and facial images presented together. The accuracy differed depending on the sex of the targets and the raters. In addition, facial and body odor attractiveness predicted the targets’ personalities and the assessments of their personalities. These results show that the accuracy of personality assessment changes when judges assess different types of stimuli.     

Do facial first impressions reflect a shared social reality?

Influential facial impression models have repeatedly shown that trustworthiness, youthful–attractiveness, and dominance dimensions subserve a wide variety of first impressions formed from strangers’ faces, suggestive of a shared social reality. However, these models are built from impressions aggregated across observers. Critically, recent work has now shown substantial inter-observer differences in facial impressions, raising the important question of whether these dimensional models based on aggregated group data are meaningful at the individual observer level. We addressed this question with a novel case series approach, using factor analyses of ratings of twelve different traits to build individual models of facial impressions for different observers. Strikingly, three dimensions of trustworthiness, youthful/attractiveness, and competence/dominance appeared across the majority of these individual observer models, demonstrating that the dimensional approach is indeed meaningful at the individual level. Nonetheless, we also found differences in the stability of the competence/dominance dimension across observers. Taken together, results suggest that individual differences in impressions arise in the context of a largely common structure that supports a shared social reality.     

Normal face-based judgements of social characteristics despite severely impaired holistic face processing

Initial evidence indicates that face-based judgements of socially relevant characteristics such as people's trustworthiness or attractiveness are linked to the configural/holistic processing of facial cues. What remains a matter of debate, however, is whether such processing is actually necessary for normal social judgements to occur and whether it resembles the type of integrative processing as required for facial identification. To address these issues, we asked a well-characterized case of acquired prosopagnosia (PS) with a marked deficit in holistic processing for face identity to rate a series of faces on several dimensions of social relevance. PS provided ratings within the normal range for most of the social characteristics probed (i.e., aggression, attractiveness, confidence, intelligence, sociability, trustworthiness). Her evaluations deviated from those of healthy controls only when facial dominance was concerned. Taken together, these data demonstrate that the inability to integrate facial information during face individuation does not necessarily translate into a generalized deficit to evaluate faces on social dimensions.     

Republican Voters Prefer Candidates Who Have Conservative‐Looking Faces: New Evidence From Exit Polls

Research shows people share common political facial stereotypes: They associate faces with political ideologies. Moreover, given that many voters rely on party affiliation, political ideology, and appearances to select political candidates, we might expect that political facial stereotypes would sway voting preferences and, by extension, the share of votes going to each candidate in an election. And yet few studies have examined whether having a stereotypically conservative‐looking (or liberal‐looking) face predicts a candidate's vote shares. Using data from U.S. election exit polls, we show that the Republican voters within each state are more likely to vote for a candidate (even a Democrat) the more that person has a stereotypically Republican‐looking face. By contrast, the voting choices of the Democratic voters within each state are unrelated to political facial stereotypes. Moreover, we show that the relationship between political facial stereotypes and voting does not depend on state‐level ideology: Republican voters in both right‐leaning (“red”) and left‐leaning (“blue”) states are more likely to vote for candidates with conservative‐looking faces. These results have several important practical and theoretical implications concerning the nature and impact of political facial stereotypes, which we discuss.     

Aging and memory for faces versus single views of faces

Differences in the ability of young adults and elderly to recognize faces were examined under two conditions. In a standard single-view condition, in which each input face was shown as one photograph, we confirmed prior findings that young adults perform better than the elderly at distinguishing photographs seen before from photographs of new faces. We also found that the elderly had more trouble distinguishing photographs seen before from photographs of(l) old faces changed in facial expression and (2) old faces changed in expression and pose. Yet there were no reliable age differences in distinguishing old-but-changed faces from entirely new faces. In a more naturalistic multi-view condition, in which each input face was shown in four poses and with two expressions, no age differences were found. A second experiment ruled out the possibility that varied repetition, by itself, removes age differences in recognizing faces. These data supported age differences in remembering facial expressions and possibly other details of photographs of faces, but not in remembering faces perse.     

Age-related similarities and differences in first impressions of trustworthiness

Trust is a particularly under-studied aspect of social relationships in older age. In the current study, young (n = 35) and older adults (n = 35) completed a series of one-shot social economic trust games in which they invested real money with trustees. There were potential gains with each investment and also a risk of losing everything if the trustee was untrustworthy. The reputation and facial appearance of each trustee were manipulated to make them appear more or less trustworthy. Results revealed that young and older adults invest more money with trustees whose facial appearance and reputation indicate that they are trustworthy rather than untrustworthy. However, older adults were more likely than young to invest with trustees who had a reputation for being untrustworthy. We discuss whether age-related differences in responding to negative information may account for an age-related increase in trust, particularly when trusting someone with a reputation for being uncooperative.     

Short-term memory for emotional faces in dysphoria

The study aimed to determine if the memory bias for negative faces previously demonstrated in depression and dysphoria generalises from long- to short-term memory. A total of 29 dysphoric (DP) and 22 non-dysphoric (ND) participants were presented with a series of faces and asked to identify the emotion portrayed (happiness, sadness, anger, or neutral affect). Following a delay, four faces were presented (the original plus three distractors) and participants were asked to identify the target face. Half of the trials assessed memory for facial emotion, and the remaining trials examined memory for facial identity. At encoding, no group differences were apparent. At memory testing, relative to ND participants, DP participants exhibited impaired memory for all types of facial emotion and for facial identity when the faces featured happiness, anger, or neutral affect, but not sadness. DP participants exhibited impaired identity memory for happy faces relative to angry, sad, and neutral, whereas ND participants exhibited enhanced facial identity memory when faces were angry. In general, memory for faces was not related to performance at encoding. However, in DP participants only, memory for sad faces was related to sadness recognition at encoding. The results suggest that the negative memory bias for faces in dysphoria does not generalise from long- to short-term memory.     

Should I trust you? Autistic traits predict reduced appearance‐based trust decisions

Facial impressions of trustworthiness guide social decisions in the general population, as shown by financial lending in economic Trust Games. As an exception, autistic boys fail to use facial impressions to guide trust decisions, despite forming typical facial trustworthiness impressions (Autism, 19, 2015a, 1002). Here, we tested whether this dissociation between forming and using facial impressions of trustworthiness extends to neurotypical men with high levels of autistic traits. Forty‐six Caucasian men completed a multi‐turn Trust Game, a facial trustworthiness impressions task, the Autism‐Spectrum Quotient, and two Theory of Mind tasks. As hypothesized, participants’ levels of autistic traits had no observed effect on the impressions formed, but negatively predicted the use of those impressions in trust decisions. Thus, the dissociation between forming and using facial impressions of trustworthiness extends to the broader autism phenotype. More broadly, our results identify autistic traits as an important source of individual variation in the use of facial impressions to guide behaviour. Interestingly, failure to use these impressions could potentially represent rational behaviour, given their limited validity.     

Mental rotation of faces

The effect of orientation upon face recognition was explored in two experiments, which used a procedure adapted from the mental rotation literature. In the first experiment, a linear increase in the RT of same-different judgments was found as the second of a pair of sequentially presented faces was rotated away from the vertical. Also, it was found that the effect of changing facial expression did not interact with orientation. In the second experiment, a linear relationship between RT and orientation was found in a task involving the recognition of famous faces. This recognition task was found to be more affected by inversion than was an expression classification task. These results are interpreted as evidence against the view that inverted faces are processed in a qualitatively different manner from upright faces, and are also inconsistent with the hypothesis that inversion makes faces difficult to recognize because facial expression cannot be extracted from an inverted face.     

Discrepant integration times for upright and inverted faces

Judgments of upright faces tend to be more rapid than judgments of inverted faces. This is consistent with encoding at different rates via discrepant mechanisms, or via a common mechanism that is more sensitive to upright input. However, to the best of our knowledge no previous study of facial coding speed has tried to equate sensitivity across the characteristics under investigation (eg emotional expression, facial gender, or facial orientation). Consequently we cannot tell whether different decision speeds result from mechanisms that accrue information at different rates, or because facial images can differ in the amount of information they make available. To address this, we examined temporal integration times, the times across which information is accrued toward a perceptual decision. We examined facial gender and emotional expressions. We first identified image pairs that could be differentiated on 80% of trials with protracted presentations (1 s). We then presented these images at a range of brief durations to determine how rapidly performance plateaued, which is indicative of integration time. For upright faces gender was associated with a protracted integration relative to expression judgments. This difference was eliminated by inversion, with both gender and expression judgments associated with a common, rapid, integration time. Overall, our data suggest that upright facial gender and expression are encoded via distinct processes and that inversion does not just result in impaired sensitivity. Rather, inversion caused gender judgments, which had been associated with a protracted integration, to become associated with a more rapid process.     

Facial first impressions and partner preference models: Comparable or distinct underlying structures?

Given the frequency of relationships nowadays initiated online, where impressions from face photographs may influence relationship initiation, it is important to understand how facial first impressions might be used in such contexts. We therefore examined the applicability of a leading model of verbally expressed partner preferences to impressions derived from real face images and investigated how the factor structure of first impressions based on potential partner preference-related traits might relate to a more general model of facial first impressions. Participants rated 1,000 everyday face photographs on 12 traits selected to represent (Fletcher, et al. 1999, Journal of Personality and Social Psychology, 76, 72) verbal model of partner preferences. Facial trait judgements showed an underlying structure that largely paralleled the tripartite structure of Fletcher et al.'s verbal preference model, regardless of either face gender or participant gender. Furthermore, there was close correspondence between the verbal partner preference model and a more general tripartite model of facial first impressions derived from a different literature (Sutherland et al., 2013, Cognition, 127, 105), suggesting an underlying correspondence between verbal conceptual models of romantic preferences and more general models of facial first impressions.     

Angry faces are more resistant to forgetting than are happy faces: directed forgetting effects on the identity of emotional faces

Using the item-method directed forgetting paradigm (i.e. intentionally forgetting specified information), we examined directed forgetting of facial identity as a function of facial expression and the sex of the expresser and perceiver. Participants were presented with happy and angry male and female faces cued for either forgetting or remembering, and were then asked to recognise previously studied faces from among a series of neutral faces. For each recognised test face, participants also recalled the face’s previously displayed emotional expression. We found that angry faces were more resistant to forgetting than were happy faces. Furthermore, angry expressions on male faces and happy expressions on female faces were recognised and recalled better than vice versa. Signal detection analyses revealed that male faces gave rise to a greater sensitivity than female faces did, and male participants, but not female participants, showed greater sensitivity to male faces than to female faces. Several theoretical implications are discussed.     

Amygdala activation during masked presentation of emotional faces predicts conscious detection of threat-related faces

It has been argued that critical functions of the human amygdala are to modulate the moment-to-moment vigilance level and to enhance the processing and the consolidation of memories of emotionally arousing material. In this functional magnetic resonance study, pictures of human faces bearing fearful, angry, and happy expressions were presented to nine healthy volunteers using a backward masking procedure based on neutral facial expression. Activation of the left and right amygdala in response to the masked fearful faces (compared to neutral faces) was significantly correlated with the number of fearful faces detected. In addition, right but not left amygdala activation in response to the masked angry faces was significantly related to the number of angry faces detected. The present findings underscore the role of the amygdala in the detection and consolidation of memory for marginally perceptible threatening facial expression.     

Memory for disguised same- and cross-race faces: The eyes have it

According to research on the cross-race effect, through experience, observers learn which diagnostic facial features are important for recognizing same-race compared to cross-race faces. These diagnostic facial features differ across racial groups; whereas the upper facial region is more diagnostic for White faces, the lower facial region is more diagnostic for Black faces. We tested how disguises at encoding (sunglasses [upper region] or bandana [lower region]) affect White and Black observers’ recognition memory for White and Black faces. We found that disguises override the diagnosticity of race-specific regions and have similar effects on recognition of same- and cross-race faces. Relative to no disguise, recognition memory was impaired more by disguising upper (sunglasses) than lower (bandana) facial regions. This supports the hypothesis that facial features trump race-specific diagnostic regions, and the eye region provides relatively more diagnostic information than lower facial features.     

First impressions from faces in the real world: Commentary on Sutherland and Young (2022)

The study of first impressions from faces now emphasizes the need to understand trait inferences made to naturalistic face images (British Journal of Psychology, 113, 2022, 1056). Face recognition algorithms based on deep convolutional neural networks simultaneously represent invariant, changeable and environmental variables in face images. Therefore, we suggest them as a comprehensive ‘face space’ model of first impressions of naturalistic faces. We also suggest that to understand trait inferences in the real world, a logical next step is to consider trait inferences made to whole people (faces and bodies). On the role of cultural contributions to trait perception, we think it is important for the field to begin to consider the way in which trait inferences motivate (or not) behaviour in independent and interdependent cultures.     

Expression influences the recognition of familiar faces

Face recognition has been assumed to be independent of facial expression. We used familiar and unfamiliar faces that were morphed from a happy to an angry expression within a given identity. Participants performed speeded two-choice decisions according to whether or not a face was familiar. Consistent with earlier findings, reaction times for classifications of unfamiliar faces were independent of facial expressions. In contrast, expression clearly influenced the recognition of familiar faces. with fastest recognition for moderately happy expressions. This suggests that representations of familiar faces for recognition preserve some information about typical emotional expressions.