First Impressions From Faces

Facial impressions of niceness influence children's interpretations of peers' ambiguous behavior

Children infer personality traits from faces when they are asked explicitly which face appears nice or mean. Less is known about how children use face-trait information implicitly to make behavioral evaluations. We used the Ambiguous Situations Protocol to explore how children use face-trait information to form interpretations of ambiguous situations when the behavior or intention of the target child was unclear. On each trial, children (N = 144, age range = 4-11.95 years; 74 girls, 67 boys, 3 gender not specified; 70% White, 10% other or mixed race, 5% Asian, 4% Black, 1% Indigenous, 9% not specified) viewed a child's face (previously rated high or low in niceness) before seeing the child's face embedded within an ambiguous scene (Scene Task) or hearing a vignette about a misbehavior done by that child (Misbehavior Task). Children described what was happening in each scene and indicated whether each misbehavior was done on purpose or by accident. Children also rated the behavior of each child and indicated whether the child would be a good friend. Facial niceness influenced children's interpretations of ambiguous behavior (Scene Task) by 4 years of age, and ambiguous intentions (Misbehavior Task) by 6 years. Our results suggest that the use of face-trait cues to form interpretations of ambiguous behavior emerges early in childhood, a bias that may lead to differential treatment for peers perceived with a high-nice face versus a low-nice face.

First impressions: Do faces with scars and palsies influence warmth, competence and humanization?

A glance is enough to assign psychological attributes to others. Attractiveness is associated with positive attributes ('beauty-is-good' stereotype). Here, we raise the question of a similar but negative bias. Are people with facial anomalies associated with negative personal characteristics? We hypothesized that biases against faces with anomalies arise because of negative stereotypes (less warmth and competence) and forms of dehumanization (animalistic and mechanistic). We enrolled 1493 mTurk participants (N = 1306 after exclusion) to assess 31 traits of photographed people using 60 pairs of photographs of the same person before and after plastic surgery. Half anomalous faces had a scar and the other half had a palsy. To calculate warmth and competence, we conducted a principal components analysis of the 31 attributes. Animalistic dehumanization was assessed by averaging reverse-scored ratings corresponding to moral sensibility and rationality/logic, and mechanistic dehumanization by averaging across reverse-scored ratings corresponding to emotional responsiveness and interpersonal warmth. We found that both kinds of anomalous faces were seen as less warm, competent and were dehumanized. Our findings suggest that an 'anomalous-is-bad' stereotype generalizes regardless of the aetiology of the anomaly. This effect may be related to a reverse halo effect, that is, the horn effect.

Predicting personality or prejudice? Facial inference in the age of artificial intelligence

Facial inference, a cornerstone of person perception, has traditionally been studied through human judgments about personality traits and abilities based on people's faces. Recent advances in artificial intelligence (AI) have introduced new dimensions to this field, employing machine learning algorithms to reveal people's character, capabilities, and social outcomes based just on their faces. This review examines recent research on human and AI-based facial inference across psychology, business, computer science, legal, and policy studies to highlight the need for scientific consensus on whether or not people's faces can reveal their inner traits, and urges researchers to address the critical concerns around epistemic validity, practical relevance, and societal welfare before recommending AI-based facial inference for consequential uses.

No evidence for an other-race effect in dominance and trustworthy judgements from faces

A variety of evidence shows that social categorization of people based on their race can lead to stereotypical judgements and prejudicial behaviour. Here, we explore the extent to which trait judgements of faces are influenced by race. To address this issue, we measured the reliability of first impressions for own-race and other-race faces in Asian and White participants. Participants viewed pairs of faces and were asked to indicate which of the two faces was more dominant or which of the two faces was more trustworthy. We measured the consistency (or reliability) of these judgements across participants for own-race and other-races faces. We found that judgements of dominance or trustworthiness showed similar levels of reliability for own-race and other-race faces. Moreover, an item analysis showed that the judgements on individual trials were very similar across participants from different races. Next, participants made overall ratings of dominance and trustworthiness from own-race and other-race faces. Again, we found that there was no evidence for an ORE. Together, these results provide a new approach to measuring trait judgements of faces and show that in these conditions there is no ORE for the perception of dominance and trustworthiness.

Association of intensity and dominance of CEOs' smiles with corporate performance

This study investigated whether the facial expressions of chief executive officers (CEOs) are associated with corporate performance. A photograph of the CEO or president of each company that appeared on the Fortune Global 500 list for 2018 was taken from the company's official website. The smile intensity and action unit activation in each face were calculated using a pre-trained machine learning algorithm, FACET. The results revealed a positive association between smile intensity and company profit, even when controlling for the company's geographic location (Western culture versus others) and the CEO's gender. Furthermore, when the type of smile was examined with the activation of each action unit, this significant positive association was identified in the dominant smile but not in the reward and affiliative smiles. Relationships among the leader's smile intensity, group strategy, and group performance are discussed.

Capuchin monkeys' (Sapajus [Cebus] apella) categorization of photos of unknown male conspecifics suggests attention to fWHR and a dominance bias

The ability to quickly perceive others' rank minimizes costs by helping individuals behave appropriately when interacting with strangers. Indeed, humans and at least some other species can quickly determine strangers' rank or dominance based only on physical features without observing others' interactions or behavior. Nonhuman primates can determine strangers' ranks by observing their interactions, and some evidence suggests that at least some cues to dominance, such as facial width-to-height ratio (fWHR), are also present in other primates. However, it is unknown whether they can determine strangers' rank simply by looking at their faces, rather than observing their interactions. If so, this would suggest selective pressure across the primates on both cues to dominance and the ability to detect those cues accurately. To address this, we examined the ability of male and female tufted capuchin monkeys (Sapajus [Cebus] apella) to categorize images of the faces of unknown conspecifics (Sapajus from different colonies) and humans (computer-generated and real) as dominant or nondominant based only on still images. Capuchins' categorization of unknown conspecific faces was consistent with fWHR, a cue to dominance, although there was a strong tendency to categorize strangers as dominant, particularly for males. This was true despite the continued correct categorization of known individuals. In addition, capuchins did not categorize human strangers in accordance with external pre-ratings of dominance by independent human raters, despite the availability of the same cue, fWHR. We consider these results in the context of capuchin socio-ecology and what they mean for the evolution of rapid decision-making in social contexts.

Associations between autistic traits, depression, social anxiety and social rejection in autistic and non-autistic adults

Autistic people frequently experience negative judgements from non-autistic people, often fuelled by misconceptions that autistic people lack empathy. Understanding responses to negative social judgement among autistic people is crucial because of the potential negative impact on wellbeing and future interactions. We investigated the role of autistic traits, social anxiety, and depression on behavioural indices of social rejection in 20 autistic (AUT; 11 males) and 40 non-autistic (N-AUT; 21 males) university students. Participants completed the Social Judgement Task (SJT) where they predicted whether they were liked by another person, then received feedback on whether those evaluations were correct. Participants also completed an Age Judgement Task (AJT) where they estimated the age of the pictured person. The AUT group had lower positive expectation scores, meaning less tendency to predict being liked. Across the whole sample, higher social anxiety predicted greater tendency to anticipate rejection from others, not autistic traits. These findings suggest early experiences of rejection might lead to a negative self-bias in autistic people and emphasise the importance of using a transdiagnostic approach by showing that social anxiety rather than autistic traits is associated with expectation of social rejection.

Putting a label on someone: impact of schizophrenia stigma on emotional mimicry, liking, and interpersonal closeness

Affiliation is both an antecedent and a consequence of emotional mimicry (i.e. imitating a counterpart's emotional expression). Thus, interacting with a disliked partner can decrease emotional mimicry, which in turn can further decrease liking. This perpetuating circle has not been investigated in the context of mental health stigma yet. The present study tested the influence of the label "schizophrenia" on liking, interpersonal closeness, and emotional mimicry. In an online experiment (n = 201), participants recruited from the general population saw several videos of actors displaying emotional expressions. Actors were described with one of four labels: "schizophrenia", "healthy", "diabetes", and a negative adjective (e.g. "hot-tempered"). Emotional mimicry was measured using OpenFace 2.2. Liking and interpersonal closeness were assessed with questionnaires. Overall, compared to other labels, participants reported less liking and interpersonal closeness to the actor with the schizophrenia label. However, no effect on emotional mimicry was found. The decreased liking of the schizophrenia actors was explained by a lack of knowledge about schizophrenia and the explicit stigma of schizophrenia. Our study contributes to the literature by highlighting the need to reduce the stigma of schizophrenia.

The aggressive face of melasma: unveiling the influence of upper lip pigmentation on social perception

Introduction

Although melasma leads to emotional distress and quality-of-life reduction, indigenous cultures practice female facial tattooing. Facial cues influence personality trait inferences and attractiveness ratings. Skin lesions have been shown to alter gaze patterns, emotion perception, and social evaluations.

Aim

This study aimed to evaluate melasma's impact on visual attention, perceived attractiveness, and social evaluations, considering distinct anatomical areas. Additionally, we sought to compare perceptions of traditional facial tattoos due to their purposeful placement.

Material and methods

Gaze fixation patterns were examined via eye-tracking, and image-based personality questionnaires were completed for psychological trait assessment. Visual stimuli showcased anatomic melasma variants and tattoo patterns.

Results

Traditional tattoos often follow midline patterns, sparing the upper lip. Both melasma and tattoos significantly affected visual attention (p < 0.001), with chin and upper lip melasma garnering increased attention. Upper lip melasma decreased gaze to the ocular area (p ≤ 0.002). while increasing perioral fixations (p < 0.001) compared to healthy faces. Upper lip tattoos conveyed increased perceived aggressiveness (p = 0.004). Ratings for attractiveness and personality traits were lower for centrofacial melasma than other variants, with no significant difference between centrofacial and isolated upper lip melasma.

Conclusions

The global avoidance of upper lip pigmentation underscores its perceptual burden. Upper lip pigmentation directs gaze towards anger-signalling regions, increasing perceived aggression and reducing attractiveness. Centrofacial melasma's impact parallels an isolated upper lip pattern, underscoring the disproportionate role of upper lip pigmentation. These findings warrant considering upper lip melasma's significant influence when evaluating quality of life and establishing treatment goals.

Racial Prejudice Affects Representations of Facial Trustworthiness

What makes faces seem trustworthy? We investigated how racial prejudice predicts the extent to which perceivers employ racially prototypical cues to infer trustworthiness from faces. We constructed participant-level computational models of trustworthiness and White-to-Black prototypicality from U.S. college students' judgments of White (Study 1, N = 206) and Black-White morphed (Study 3, N = 386) synthetic faces. Although the average relationships between models differed across stimuli, both studies revealed that as participants' anti-Black prejudice increased and/or intergroup contact decreased, so too did participants' tendency to conflate White prototypical features with trustworthiness and Black prototypical features with untrustworthiness. Study 2 (N = 324) and Study 4 (N = 397) corroborated that untrustworthy faces constructed from participants with pro-White preferences appeared more Black prototypical to naive U.S. adults, relative to untrustworthy faces modeled from other participants. This work highlights the important role of racial biases in shaping impressions of facial trustworthiness.

Racism is not about "race"

Unfamiliar individuals are viewed with suspicion across the entire animal kingdom. This makes evolutionary sense, as outsiders may carry unfamiliar pathogens against which one has not yet developed immune defenses. In humans, the unfamiliar-pathogens idea has been dismissed on the grounds that people do not shun microbe-sharing contact with ethnic outgroups (other "races") more than they do with ingroups. Reanalyzing the same public data on which such claims are based-6500 participants from China, India, USA, and UK-here I show that (1) people do behave as though the parasites of unfamiliar individuals were more dangerous, and (2) strangers' ethnicity matters when, and only when, it is a proxy for unfamiliarity. This implies that racism could be tamed by acquainting our children with fellow humans of all shapes and colors, so that everyone in the world looks like family.

Face coverings increase apparent honesty and cooperativeness

People readily make inferences about trait-like characteristics of another person's face. Since the recent global COVID-19 pandemic, the widespread use of hygienic face masks has led to large proportions of the face being covered. We investigated the effect of face masks on the inference of prosocially relevant characteristics, namely cooperativeness and honesty. Portraits of participants of previous studies from which we knew their "true" prosocial tendencies served as stimuli. These facial stimuli were presented once with and once without a hygienic face mask to 60 naïve participants who rated the faces for cooperativeness and honesty. Results revealed that wearing face masks made people generally appear more cooperative and more honest than without a mask, but that these ratings were unrelated to the true prosocial tendencies of these people. Together, these findings have important implications for social interactions, particularly in contexts where nonverbal communication is essential, such as in healthcare settings, job interviews, and social gatherings.

Facial first impressions are not mandatory: A priming investigation

A common assertion is that, based around prominent character traits, first impressions are spontaneously extracted from faces. Specifically, mere exposure to a person is sufficient to trigger the involuntary extraction of core personality characteristics (e.g., trustworthiness, dominance, competence), an outcome that supports a range of significant judgments (e.g., hiring, investing, electing). But is this in fact the case? Noting ambiguities in the extant literature, here we used a repetition priming procedure to probe the extent to which impressions of dominance are extracted from faces absent the instruction to evaluate the stimuli in this way. Across five experiments in which either the character trait of interest was made increasingly obvious to participants (Expts. 1-3) or attention was explicitly directed toward the faces to generate low-level/high-level judgments (Expts. 4 & 5), no evidence for the spontaneous extraction of first impressions was observed. Instead, priming only emerged when judgments of dominance were an explicit requirement of the task at hand. Thus, at least using a priming methodology, the current findings contest the notion that first impressions are a mandatory product of person perception.

When he smiles: Attractiveness preferences for male faces expressing emotions

The impact of sexual dimorphism on facial attractiveness has been controversial owing to contradictory results, particularly in studies on female preferences. Given that sexually dimorphic facial features, especially more masculine ones, have been previously related to the perception of anger, we investigated the bi-directional influence of emotional expressions and facial masculinity and explored their impact on women's preferences for facial masculinity. We confirmed the effect of facial sexual dimorphism on the perception of emotional cues (happiness and anger) and explored whether smiling or angry expressions influence women's perception of masculinity in male faces. Additionally, we examined women's preferences for emotionally expressive male faces altered along a continuum of masculinity. The results showed that masculinised faces are perceived as angrier, while feminised faces are perceived as happier (Experiment 1), and that angry faces are perceived as more masculine when compared with happy faces (Experiment 2). It is noteworthy that our Experiment 3 uncovered a pivotal finding: women prefer reduced feminisation in happy faces compared with neutral/angry faces. This suggests that the avoidance response observed towards masculinity is attenuated by a smiling expression. The current study introduces a new perspective to be considered when exploring the role of facial masculinity in women's attractiveness preferences.

A multidimensional implicit approach to gender stereotypes

Research has widely explained gender inequalities in terms of gender stereotypes, according to which women are considered more nurturing, empathic, and emotional but less competent - than men. Recent evidence highlights that especially women are portrayed along multiple dimensions. In this research, we adopted an implicit Semantic Misattribution procedure to detect whether gender stereotypes have a multidimensional structure and are differently attributed to men and women. Results showed that Competence and Dominance-related terms were considered more masculine ones. In contrast, Morality and Physical Attractiveness were attributed to feminine ideograms to a higher and significant extent than masculine ones. Sociability was related to feminine and masculine ideograms almost to the same extent. The gathered evidence provided a multidimensional picture even composed of more judgment dimensions with reference to women highlighting how it can be difficult for them to meet all those multiple expectancies.

Learning emotional dialects: A British population study of cross-cultural communication

The aim of the current research was to explore whether we can improve the recognition of cross-cultural freely-expressed emotional faces in British participants. We tested several methods for improving the recognition of freely-expressed emotional faces, such as different methods for presenting other-culture expressions of emotion from individuals from Chile, New Zealand and Singapore in two experimental stages. In the first experimental stage, in phase one, participants were asked to identify the emotion of cross-cultural freely-expressed faces. In the second phase, different cohorts were presented with interactive side-by-side, back-to-back and dynamic morphing of cross-cultural freely-expressed emotional faces, and control conditions. In the final phase, we repeated phase one using novel stimuli. We found that all non-control conditions led to recognition improvements. Morphing was the most effective condition for improving the recognition of cross-cultural emotional faces. In the second experimental stage, we presented morphing to different cohorts including own-to-other and other-to-own freely-expressed cross-cultural emotional faces and neutral-to-emotional and emotional-to-neutral other-culture freely-expressed emotional faces. All conditions led to recognition improvements and the presentation of freely-expressed own-to-other cultural-emotional faces provided the most effective learning. These findings suggest that training can improve the recognition of cross-cultural freely-expressed emotional expressions.

Predictors of female age, health and attractiveness perception from skin feature analysis of digital portraits in five ethnic groups

OBJECTIVE

Research indicates the impact of skin colour, tone evenness and surface topography on ratings of age, health and attractiveness in women. In addition to subjective assessments, these effects have been quantified with objective measures derived from skin image analysis. Signs of skin ageing may manifest differently across ethnic groups. However, comparisons have been limited to research with two ethnic groups, preventing conclusions about an ethnicity-specific ranking of skin ageing signs.

METHODS

We report results from a multi-ethnic and multi-centre study in which faces of women (n = 180; aged 20-69 years) from five ethnic groups were imaged. Facial images were rated for age, health and attractiveness by members of the same ethnic group (each n = 120). Digital image analysis was used to quantify skin colour, gloss, tone evenness and wrinkling/sagging. We assessed associations between face ratings and skin image measurements in the total sample (i.e. all ethnic groups) and separately by ethnicity.

RESULTS

Skin image analysis revealed differences between ethnic groups, including skin colour, gloss, tone evenness, wrinkling and sagging. Differences in the relative predictive utility of individual skin features in accounting for ratings of age, health and attractiveness also were observed between ethnic groups. Facial wrinkling and sagging were the best predictors of face ratings in each ethnic group, with some differences in the type (or predictive magnitude) of skin features.

CONCLUSION

The current findings corroborate previous reports of differences between ethnic groups in female facial skin and indicate differential effects of skin features on ratings of age, health and attractiveness, within and between ethnic groups. Facial wrinkling and sagging were the best predictors of age and attractiveness ratings, and skin tone evenness and gloss had an additional role in ratings of health.

Virtual first impressions: Zoom backgrounds affect judgements of trust and competence

Trait inferences from first impressions are drawn rapidly and spontaneously. However, the Covid-19 pandemic forced interactions online introducing differential influential factors on first impressions. As such, there is an absence of research investigating video background on videoconferencing impression formation. This study explored the influence of video background, facial expression, and gender on first impressions of trustworthiness and competence. Video background affected trustworthy and competence perceptions with Plants and Book backgrounds scoring highly on both dimensions while the Home and Novelty backgrounds consistently received the lowest ratings. Happy faces were perceived as more trustworthy and more competent while female faces were also rated as more trustworthy and more competent, regardless of the background they were using. The explanations for these findings are discussed, along with future directions for research and the implications for videoconferencing use.

First impressions of a new face are shaped by infection concerns

Along with a classical immune system, we have evolved a behavioral one that directs us away from potentially contagious individuals. Here I show, using publicly available cross-cultural data, that this adaptation is so fundamental that our first impressions of a male stranger are largely driven by the perceived health of his face. Positive (likeable, capable, intelligent, trustworthy) and negative (unfriendly, ignorant, lazy) first impressions are affected by facial health in adaptively different ways, inconsistent with a mere halo effect; they are also modulated by one's current state of health and inclination to feel disgusted by pathogens. These findings, which replicated across two countries as different as the USA and India, suggest that instinctive perceptions of badness and goodness from faces are not two sides of the same coin but reflect the (nonsymmetrical) expected costs and benefits of interaction. Apparently, pathogens run the show-and first impressions come second. Lay Summary: Our first impressions of strangers (whether they seem trustworthy, intelligent, unfriendly, or aggressive) are shaped by how healthy their faces look and by our unconscious motivation to avoid infections. Bad and good impressions turn out to reflect the concrete, potentially vital, expected costs and benefits of interacting with our fellow humans. Apparently, pathogens run the show-and first impressions come second.

Hits and Misses: Digital Contact Tracing in a Pandemic

Traditional contact tracing is one of the most powerful weapons people have in the battle against a pandemic, especially when vaccines do not yet exist or do not afford complete protection from infection. But the effectiveness of contact tracing hinges on its ability to find infected people quickly and obtain accurate information from them. Therefore, contact tracing inherits the challenges associated with the fallibilities of memory. Against this backdrop, digital contact tracing is the "dream scenario"-an unobtrusive, vigilant, and accurate recorder of danger that should outperform manual contact tracing on every dimension. There is reason to celebrate the success of digital contact tracing. Indeed, epidemiologists report that digital contact tracing probably reduced the incidence of COVID-19 cases by at least 25% in many countries, a feat that would have been hard to match with its manual counterpart. Yet there is also reason to speculate that digital contact tracing delivered on only a fraction of its potential because it almost completely ignored the relevant psychological science. We discuss the strengths and weaknesses of digital contact tracing, its hits and misses in the COVID-19 pandemic, and its need to be integrated with the science of human behavior.

Iterated learning reveals stereotypes of facial trustworthiness that propagate in the absence of evidence

When we look at someone's face, we rapidly and automatically form robust impressions of how trustworthy they appear. Yet while people's impressions of trustworthiness show a high degree of reliability and agreement with one another, evidence for the accuracy of these impressions is weak. How do such appearance-based biases survive in the face of weak evidence? We explored this question using an iterated learning paradigm, in which memories relating (perceived) facial and behavioral trustworthiness were passed through many generations of participants. Stimuli consisted of pairs of computer-generated people's faces and exact dollar amounts that those fictional people shared with partners in a trust game. Importantly, the faces were designed to vary considerably along a dimension of perceived facial trustworthiness. Each participant learned (and then reproduced from memory) some mapping between the faces and the dollar amounts shared (i.e., between perceived facial and behavioral trustworthiness). Much like in the game of 'telephone', their reproductions then became the training stimuli initially presented to the next participant, and so on for each transmission chain. Critically, the first participant in each chain observed some mapping between perceived facial and behavioral trustworthiness, including positive linear, negative linear, nonlinear, and completely random relationships. Strikingly, participants' reproductions of these relationships showed a pattern of convergence in which more trustworthy looks were associated with more trustworthy behavior - even when there was no relationship between looks and behavior at the start of the chain. These results demonstrate the power of facial stereotypes, and the ease with which they can be propagated to others, even in the absence of any reliable origin of these stereotypes.

The Efficacy and Duration of Onabotulinum Toxin A in Improving Upper Facial Expression Lines With 64-Unit Dose Optimization: A Systematic Review and Meta-Analysis With Trial Sequential Analysis of the Randomized Controlled Trials

BACKGROUND

Onabotulinumtoxin A (Onabot A) was the first treatment to be approved for aesthetic indications, namely glabellar lines (GLs), crow's feet lines (CFLs), and forehead lines (FHLs), with a cumulative dose of 64 U.

OBJECTIVES

The aim of this study was to conduct a meta-analysis to combine the available data for approved doses for GLs, CFLs, and FHLs to explore the effect and duration of simultaneous treatment with Onabot A.

METHODS

PubMed/MEDLINE, Embase, and other national clinical trial registries were searched for randomized controlled trials from January 2010 to July 2022. The meta-analysis, trial sequential analysis, and investigator-assessed time to return to nonresponder status in GLs, CFLs, and FHLs following Onabot A were plotted to elicit a cumulative dose-adjusted response curve based on Kaplan-Meier analysis with a log-rank test.

RESULTS

Fourteen randomized controlled trials were eligible for quantitative analysis. A total of 8369 subjects were recruited across the trials. The meta-analysis results show that Onabot A is very effective in reducing moderate to severe GLs, CFLs, and FHLs. The cumulative Z-curve for GLs, CFLs, and FHLs also exceeds the required information size (RIS). Kaplan-Meier analysis with a log-rank test demonstrated that simultaneous treatment of GLs, CFLs, and FHLs requires 182 days (95% CI = 179, 215 days) (P < 0.00002) to return to nonresponder status.

CONCLUSIONS

Treatment of the upper facial expression lines with Onabot A is effective, and the approved cumulative dose of 64 U gives longer-lasting effects.

LEVEL OF EVIDENCE: 1

Contextual modulation of appearance-trait learning

When we encounter a stranger for the first time, we spontaneously attribute to them a wide variety of character traits based on their facial appearance. There is increasing consensus that learning plays a key role in these first impressions. According to the Trait Inference Mapping (TIM) model, first impressions are the products of mappings between 'face space' and 'trait space' acquired through domain-general associative processes. Drawing on the associative learning literature, TIM predicts that first-learned associations between facial appearance and character will be particularly influential: they will be difficult to unlearn and will be more likely to generalise to novel contexts than appearance-trait associations acquired subsequently. The study of face-trait learning de novo is complicated by the fact that participants, even young children, already have extensive experience with faces before they enter the lab. This renders the study of first-learned associations from faces intractable. Here, we overcome this problem by using Greebles - a class of novel synthetic objects about which participants had no previous knowledge or preconceptions - as a proxy for faces. In four experiments (total N = 640) with adult participants we adapt classic AB-A and AB-C renewal paradigms to study appearance-trait learning. Our results indicate that appearance-trait associations are subject to contextual control, and are resistant to counter-stereotypical experience.

Face-to-trait inferences in Japanese children and adults based on Caucasian faces

Recently, many studies have indicated that humans make social evaluations from facial appearances instantaneously and automatically. Furthermore, such judgments play an important role in several social contexts. However, the mechanisms involved in the ability to form impressions from faces are still unknown, as is the extent to which these can be regarded as universal in perceiving impressions. In the current study, computer-generated Caucasian faces were used to assess the universality or cultural differences in impression formation among Japanese children and adults. This study hypothesized that impressions of trustworthiness and dominance may be more fundamental and universal, whereas the impression of competence may be more complex and culture-dependent. In Experiment 1a, 42 children aged 3-6 years were presented with 10 pairs of face images and asked which image in each pair was more trustworthy, dominant, or competent. Overall, it was found that as age increased, the rate of agreement of Japanese participants with the judgment of American participants, obtained in a previous study, increased. However, the agreement rate for competence was relatively low. Experiment 1b, conducted with 46 children, was a replication of Experiment 1a, and the results showed the same tendency. In Experiment 2, 45 Japanese adults made impression judgments on 19 pairs of face images identical to those used in Experiment 1b. The results suggested that while dominance was a dimension not easily influenced by developmental changes or culture, trustworthiness could be influenced by cultural differences in facial expression recognition. Therefore, different judgment criteria are used for children and adults. For competence, the agreement rate with Americans was relatively stable and low among the different age groups. This suggests that depending on the dimension of the trait, certain judgments are influenced by cultural context and, therefore, change criteria, while others are based on more universal criteria.

Preferential looking studies of trustworthiness detection confound structural and expressive cues to facial trustworthiness

On encountering a stranger, we spontaneously attribute to them character traits (e.g., trustworthiness, intelligence) based on their facial appearance. Participants can base impressions on structural face cues-the stable aspects of facial appearance that support identity recognition-or expression cues, such as the presence of a smile. It has been reported that 6- to 8-month-old infants attend to faces that adults judge to be trustworthy in preference to faces judged untrustworthy. These results are striking because the face stimuli employed were ostensibly emotion neutral. Consequently, these preferential looking effects have been taken as evidence for innate sensitivity to structural face cues to trustworthiness. However, scrutiny of the emotion rating procedure used with adults suggests that the face stimuli employed may have been judged emotion neutral only when interleaved with more obvious examples of facial affect. This means that the faces may vary in emotional expression when compared to each other. Here, we report new evidence obtained from adult raters that the stimuli used in these studies confound trustworthiness and untrustworthiness with the presence of happiness and anger, respectively. These findings suggest that the preferential looking effects described in infants are compatible with a preference for positive facial affect and may not reflect early sensitivity to structural face cues to trustworthiness.

Trustworthiness perception is mandatory: Task instructions do not modulate fast periodic visual stimulation trustworthiness responses

Although it is often assumed that humans spontaneously respond to the trustworthiness of others’ faces, it is still unclear whether responses to facial trust are mandatory or can be modulated by instructions. Considerable scientific interest lies in understanding whether trust processing is mandatory, given the societal consequences of biased trusting behavior. We tested whether neural responses indexing trustworthiness discrimination depended on whether the task involved focusing on facial trustworthiness or not, using a fast periodic visual stimulation electroencephalography oddball paradigm with a neural marker of trustworthiness discrimination at 1 Hz. Participants judged faces on size without any reference to trust, explicitly formed impressions of facial trust, or were given a financial lending context that primed trust, without explicit trust judgement instructions. Significant trustworthiness discrimination responses at 1 Hz were found in all three conditions, demonstrating the robust nature of trustworthiness discrimination at the neural level. Moreover, no effect of task instruction was observed, with Bayesian analyses providing moderate to decisive evidence that task instruction did not affect trustworthiness discrimination. Our finding that visual trustworthiness discrimination is mandatory points to the remarkable spontaneity of trustworthiness processing, providing clues regarding why these often unreliable impressions are ubiquitous.

A data-driven, hyper-realistic method for visualizing individual mental representations of faces

Research in person and face perception has broadly focused on group-level consensus that individuals hold when making judgments of others (e.g., “X type of face looks trustworthy”). However, a growing body of research demonstrates that individual variation is larger than shared, stimulus-level variation for many social trait judgments. Despite this insight, little research to date has focused on building and explaining individual models of face perception. Studies and methodologies that have examined individual models are limited in what visualizations they can reliably produce to either noisy and blurry or computer avatar representations. Methods that produce low-fidelity visual representations inhibit generalizability by being clearly computer manipulated and produced. In the present work, we introduce a novel paradigm to visualize individual models of face judgments by leveraging state-of-the-art computer vision methods. Our proposed method can produce a set of photorealistic face images that correspond to an individual's mental representation of a specific attribute across a variety of attribute intensities. We provide a proof-of-concept study which examines perceived trustworthiness/untrustworthiness and masculinity/femininity. We close with a discussion of future work to substantiate our proposed method.

The Effect of Wearing a Mask on Facial Attractiveness

Background

The COVID-19 pandemic necessitated masking in public spaces. Masks may impact the perceived attractiveness of individuals and hence, interpersonal relations.

Objectives

To determine if facial coverings affect attractiveness.

Methods

An online survey was conducted using 114 headshot images, 2 each-unmasked and masked-of 57 individuals. Two hundred and seven participants rated them on an ordinal scale from 1 (least attractive) to 10 (most attractive). Parametric and nonparametric tests were performed, as appropriate, for comparison.

Results

For the first quartile, the average rating increased significantly when wearing a mask (5.89 ± 0.29 and 6.54 ± 0.67; P = 0.01). For control images ranked within the fourth quartile, the average rating decreased significantly when wearing a mask (7.60 ± 0.26 and 6.62 ± 0.55; P < 0.001). In the female subgroup (n = 34), there was a small increase in average rating when masked, whereas in the male subgroup (n = 23), there was a small decrease in average rating when masked, but the change was not statistically significant (P > 0.05). For unmasked female images ranked within the first quartile, the average rating increased significantly when wearing a mask (5.77 ± 0.27 and 6.76 ± 0.36; P = 0.001). For the female subgroup with mean ratings within the fourth quartile, the average decreased significantly when wearing a medical mask (7.53 ± 0.30 and 6.77 ± 0.53; P < 0.05). For unmasked male images ranked within the first quartile, the average rating increased when wearing a medical mask but the change was not statistically significant (P > 0.05), whereas for the control male images within the fourth quartile, the average rating decreased significantly when masked (7.72 ± 0.18 and 6.50 ± 0.54; P < 0.05).

Conclusions

While wearing a facial covering significantly increased attractiveness for images less attractive at baseline, and decreased attractiveness for those that are more attractive at baseline; it did not cause a significant overall change in attractiveness in the study population.

Level of Evidence 5

Emotional Faces Facilitate Statistical Learning

Detecting regularities and extracting patterns is a vital skill to organize complex information in our environments. Statistical learning, a process where we detect regularities by attending to relationships between cues in our environment, contributes to knowledge acquisition across myriad domains. However, less is known about how emotional cues-specifically facial configurations of emotion-influence statistical learning. Here, we tested two pre-registered aims to advance knowledge about emotional signals and statistical learning: (1) we examined statistical learning in the context of emotional compared to non-emotional information, and (2) we assessed how emotional congruency (i.e., whether facial stimuli conveyed the same, or different emotions) influenced regularity extraction. We demonstrated statistical learning in the context of emotional signals. Further, we showed that statistical learning occurs more efficiently in the context of emotional faces. We also established that congruent cues benefited an online measure of statistical learning, but had varied effects when statistical learning was assessed via post-exposure recognition test. The results shed light on how affective signals influence well-studied cognitive skills and address a knowledge gap about how cue congruency impacts statistical learning, including how emotional cues might guide predictions in our social world.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42761-022-00130-9.

People perception and stereotype-based responding: task context matters

Whether group impact social perception is a topic of renewed theoretical and empirical interest. In particular, it remains unclear when and how the composition of a group influences a core component of social cognition-stereotype-based responding. Accordingly, exploring this issue, here we investigated the extent to which different task requirements moderate the stereotype-related products of people perception. Following the presentation of same-sex groups that varied in facial typicality (i.e., high or low femininity/masculinity), participants had to report either the gender-related status of target words (i.e., a group-irrelevant gender-classification task) or whether the items were stereotypic or counter-stereotypic with respect to the preceding groups (i.e., a group-relevant stereotype-status task). Critically, facial typicality only impacted performance in the stereotype-status task. A further computational analysis (i.e., Diffusion Model) traced this effect to the combined operation of stimulus processing and response biases during decision-making. Specifically, evidence accumulation was faster when targets followed groups that were high (vs. low) in typicality and these arrays also triggered a stronger bias toward stereotypic (vs. counter-stereotypic) responses. Collectively, these findings elucidate when and how group variability influences people perception.

The effect of orthodontic treatment on facial attractiveness: a systematic review and meta-analysis

BACKGROUND

Facial and smile attractiveness are significant motivating factor for patients to seek orthodontic treatment. Although there is a general belief that orthodontic treatment improves facial appearance, this has yet not been systematically evaluated.

OBJECTIVE

The objective of this study was to assess the current evidence on the effect of orthodontic treatment on facial attractiveness.

SEARCH METHODS

Systematic and unrestricted search of nine databases were performed up to January 2022.

SELECTION CRITERIA

Studies evaluating facial attractiveness before and after orthodontic treatment.

DATA COLLECTION AND ANALYSIS

Extracted data included study design and setting, sample size and demographics, malocclusion type, treatment modality, and method for outcome assessment. Risk of bias was assessed with the ROBINS-I tool for non-randomized studies and with RoB-2 for randomized controlled trials (RCTs). Random-effects meta-analyses of mean differences and their 95% confidence intervals (CIs) were performed.

RESULTS

Twenty studies were included in data synthesis; three randomized controlled clinical trials and 17 non-randomized clinical studies of retrospective or prospective design. One of the RCTs was found to have low risk of bias, one presented some concerns and the third showed a high risk of bias. All non-randomized studies showed either unclear or high risk of bias. Data syntheses showed that orthodontic treatment improved facial attractiveness ratings by 9% when compared with untreated controls (MD: 9.05/95% CI: 4.71; 13.39). A combination of orthodontics and orthognathic surgery also showed a positive effect of 5.5% (MD: 5.51/95% CI: 1.55; 9.47) when compared with orthodontic treatment alone. There was no difference in effect between extraction and non-extraction treatments (MD: -0.89/ 95% CI: -8.72; 6.94) or between different types of Class II correctors (MD: 2.21/95% CI: -16.51; 20.93).

LIMITATIONS

With the exception of two RCTs, included studies were of unclear or low quality.

CONCLUSIONS

Orthodontic treatment has a clinically weak effect on facial attractiveness when compared to no treatment. The same is true when a combined orthodontic/surgical treatment is compared to orthodontics alone.

REGISTRATION

PROSPERO #: CRD42020169904.

Set the tone: Trustworthy and dominant novel voices classification using explicit judgement and machine learning techniques

Prior research has established that valence-trustworthiness and power-dominance are the two main dimensions of voice evaluation at zero-acquaintance. These impressions shape many of our interactions and high-impact decisions, so it is crucial for many domains to understand this dynamic. Yet, the relationship between acoustical properties of novel voices and personality/attitudinal traits attributions remains poorly understood. The fundamental problem of understanding vocal impressions and relative decision-making is linked to the complex nature of the acoustical properties in voices. In order to disentangle this relationship, this study extends the line of research on the acoustical bases of vocal impressions in two ways. First, by attempting to replicate previous finding on the bi-dimensional nature of first impressions: using personality judgements and establishing a correspondence between acoustics and voice-first-impression (VFI) dimensions relative to sex (Study 1). Second (Study 2), by exploring the non-linear relationships between acoustical parameters and VFI by the means of machine learning models. In accordance with literature, a bi-dimensional projection comprising valence-trustworthiness and power-dominance evaluations is found to explain 80% of the VFI. In study 1, brighter (high center of gravity), smoother (low shimmers), and louder (high minimum intensity) voices reflected trustworthiness, while vocal roughness (harmonic to noise-ratio), energy in the high frequencies (Energy3250), pitch (Quantile 1, Quantile 5) and lower range of pitch values reflected dominance. In study 2, above chance classification of vocal profiles was achieved by both Support Vector Machine (77.78%) and Random-Forest (Out-Of-Bag = 36.14) classifiers, generally confirming that machine learning algorithms could predict first impressions from voices. Hence results support a bi-dimensional structure to VFI, emphasize the usefulness of machine learning techniques in understanding vocal impressions, and shed light on the influence of sex on VFI formation.

The cultural learning account of first impressions

Humans spontaneously attribute character traits to strangers based on their facial appearance. Although these 'first impressions' typically have no basis in reality, some authors have assumed that they have an innate origin. By contrast, the Trait Inference Mapping (TIM) account proposes that first impressions are products of culturally acquired associative mappings that allow activation to spread from representations of facial appearance to representations of trait profiles. According to TIM, cultural instruments, including propaganda, illustrated storybooks, art and iconography, ritual, film, and TV, expose many individuals within a community to common sources of correlated face-trait experience, yielding first impressions that are shared by many, but typically inaccurate. Here, we review emerging empirical findings, many of which accord with TIM, and argue that future work must distinguish first impressions based on invariant facial features (e.g., shape) from those based on facial behaviours (e.g., expressions).

Tracking sexual dimorphism of facial width-to-height ratio across the lifespan: implications for perceived aggressiveness

The facial width-to-height ratio (FWHR) influences social judgements like perceived aggression. This may be because FWHR is a sexually dimorphic feature, with males having higher FWHR than females. However, evidence for sexual dimorphism is mixed, little is known about how it varies with age, and the relationship between sexual dimorphism and perceived aggressiveness is unclear. We addressed these gaps by measuring FWHR of 17 607 passport images of male and female faces across the lifespan. We found larger FWHR in males only in young adulthood, aligning with the stage most commonly associated with mate selection and intrasexual competition. However, the direction of dimorphism was reversed after 48 years of age, with females recording larger FWHRs than males. We then examined how natural variation in FWHR affected perceived aggressiveness. The relationship between FWHR and perceived aggressiveness was strongest for males at 27-33 and females at 34-61. Raters were most sensitive to differences in FWHR for young adult male faces, pointing to enhanced sensitivity to FWHR as a cue to aggressiveness. This may reflect a common mechanism for evaluating male aggressiveness from variability in structural (FWHR) and malleable (emotional expression) aspects of the face.

Tracking sexual dimorphism of facial width-to-height ratio across the lifespan: implications for perceived aggressiveness

The facial width-to-height ratio (FWHR) influences social judgements like perceived aggression. This may be because FWHR is a sexually dimorphic feature, with males having higher FWHR than females. However, evidence for sexual dimorphism is mixed, little is known about how it varies with age, and the relationship between sexual dimorphism and perceived aggressiveness is unclear. We addressed these gaps by measuring FWHR of 17 607 passport images of male and female faces across the lifespan. We found larger FWHR in males only in young adulthood, aligning with the stage most commonly associated with mate selection and intrasexual competition. However, the direction of dimorphism was reversed after 48 years of age, with females recording larger FWHRs than males. We then examined how natural variation in FWHR affected perceived aggressiveness. The relationship between FWHR and perceived aggressiveness was strongest for males at 27-33 and females at 34-61. Raters were most sensitive to differences in FWHR for young adult male faces, pointing to enhanced sensitivity to FWHR as a cue to aggressiveness. This may reflect a common mechanism for evaluating male aggressiveness from variability in structural (FWHR) and malleable (emotional expression) aspects of the face.

Face masks have a limited influence on first impressions: evidence from three experiments

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.

Deep models of superficial face judgments

We quickly and irresistibly form impressions of what other people are like based solely on how their faces look. These impressions have real-life consequences ranging from hiring decisions to sentencing decisions. We model and visualize the perceptual bases of facial impressions in the most comprehensive fashion to date, producing photorealistic models of 34 perceived social and physical attributes (e.g., trustworthiness and age). These models leverage and demonstrate the utility of deep learning in face evaluation, allowing for 1) generation of an infinite number of faces that vary along these perceived attribute dimensions, 2) manipulation of any face photograph along these dimensions, and 3) prediction of the impressions any face image may evoke in the general (mostly White, North American) population.

The diversity of human faces and the contexts in which they appear gives rise to an expansive stimulus space over which people infer psychological traits (e.g., trustworthiness or alertness) and other attributes (e.g., age or adiposity). Machine learning methods, in particular deep neural networks, provide expressive feature representations of face stimuli, but the correspondence between these representations and various human attribute inferences is difficult to determine because the former are high-dimensional vectors produced via black-box optimization algorithms. Here we combine deep generative image models with over 1 million judgments to model inferences of more than 30 attributes over a comprehensive latent face space. The predictive accuracy of our model approaches human interrater reliability, which simulations suggest would not have been possible with fewer faces, fewer judgments, or lower-dimensional feature representations. Our model can be used to predict and manipulate inferences with respect to arbitrary face photographs or to generate synthetic photorealistic face stimuli that evoke impressions tuned along the modeled attributes.

Cross-modal impression updating: Dynamic impression updating from face to voice and the other way around

Research has shown that faces and voices shape impression formation. Most studies have examined either the impact of faces and voices in isolation or the relative contribution of each source when presented simultaneously. However, only a few studies have questioned whether and how impressions formed via one source can be updated due to incremental information gathered from the alternative source. Yet, cross-modal impression updating is key to shed light on person perception. Thus, we tested whether positive and negative face- and voice-based impressions could be updated by inconsistent cross-modal information. In Experiment 1 (N = 130), we tested whether face-based impressions could be updated by (in)consistent voices. In Experiment 2 (N = 262), we compared face-to-voice and voice-to-face impression updating. In Experiment 3 (N = 242), we favoured a more direct comparison of the two types of stimuli (i.e., the co-occurrence of both cue types when the new information is revealed). Results showed that voices have the greatest updating impact and that the updating effect of faces was halved when voices co-occurred for a second time. We discussed these results as evidence of the dynamical evolution of cross-modal impressions.

Reduced Perceived Trustworthiness during Face Mask Wearing

To curb the diffusion of the novel coronavirus (SARS-CoV-2), governments worldwide have introduced different policies, including lockdowns, social distancing, and mandatory mask wearing. Face mask wearing, especially, has an impact on the formation of first impressions, given that when meeting someone for the first time, individuals rely on the only available piece of information, the newly met person's aesthetic appearance, in order to make initial estimations of other traits, such as competence, intelligence, or trustworthiness. However, face mask wearing affects the aesthetic appearance of an individual, creating uncertainty which, in turn, has been reported to reduce others' perceived trustworthiness. In this paper, the influence of face mask wearing on strangers' perceived trustworthiness and aesthetic appearance is assessed to verify the impact of this policy on impression formation. Participants (N = 71) have been instructed to assess the trustworthiness and the aesthetic appearance of a selection of 96 images depicting individuals of different ages (children, adults, and older adults), gender (men and women), and ethnicity (Asians or Caucasians). Participants were randomly divided into two groups: an experimental group and a control group. Participants in the experimental group (N = 38) rated faces of individuals wearing a face mask, while participants in the control group rated the same faces but in the absence of a face mask. Images were presented in random order. For each face, participants were asked to rate the aesthetic appearance and perceived trustworthiness of the stranger on two different 100-point Likert scales. Results demonstrate that (i) the correlation between perceived trustworthiness and aesthetic appearance is not affected by the presence of a face mask, and (ii) age, but not ethnicity and gender, influences the magnitude of differences in perceived trustworthiness levels during mask wearing.

Impact of perceived interpersonal similarity on attention to the eyes of same-race and other-race faces

One reason for the persistence of racial discrimination may be anticipated dissimilarity with racial outgroup members that prevent meaningful interactions. In the present research, we investigated whether perceived similarity would impact the processing of same-race and other-race faces. Specifically, in two experiments, we varied the extent to which White participants were ostensibly similar to targets via bogus feedback on a personality test. With an eye tracker, we measured the effect of this manipulation on attention to the eyes, a critical region for person perception and face memory. In Experiment 1, we monitored the impact of perceived interpersonal similarity on White participants’ attention to the eyes of same-race White targets. In Experiment 2, we replicated this procedure, but White participants were presented with either same-race White targets or other-race Black targets in a between-subjects design. The pattern of results in both experiments indicated a positive linear effect of similarity—greater perceived similarity between participants and targets predicted more attention to the eyes of White and Black faces. The implications of these findings related to top-down effects of perceived similarity for our understanding of basic processes in face perception, as well as intergroup relations, are discussed.

Why is the literature on first impressions so focused on White faces?

We spontaneously attribute to strangers a wide variety of character traits based on their facial appearance. While these first impressions have little or no basis in reality, they exert a strong influence over our behaviour. Cognitive scientists have revealed a great deal about first impressions from faces including their factor structure, the cues on which they are based, the neurocognitive mechanisms responsible, and their developmental trajectory. In this field, authors frequently strive to remove as much ethnic variability from stimulus sets as possible. Typically, this convention means that participants are asked to judge the likely traits of White faces only. In the present article, we consider four possible reasons for the lack of facial diversity in this literature and find that it is unjustified. Next, we illustrate how the focus on White faces has undermined scientific efforts to understand first impressions from faces and argue that it reinforces socially regressive ideas about 'race' and status. We go on to articulate our concern that opportunities may be lost to leverage the knowledge derived from the study of first impressions against the dire consequences of prejudice and discrimination. Finally, we highlight some promising developments in the field.

Susceptibility to Ingroup Influence in Adolescents With Intellectual Disability: A Minimal Group Experiment on Social Judgment Making

Adolescents with intellectual disability (ID) experience challenges and uncertainty when making judgments about other people's intentions. In an attempt to achieve certainty, they might exhibit judgment tendencies that differ from those of typically developing adolescents. This study investigated social judgment making in adolescents with ID (n = 34, M age = 14.89 years, SD = 1.41 years) compared with chronological age-matched adolescents without ID (n = 34, M age = 14.68 years, SD = 1.15 years) and mental age (MA)-matched children (n = 34, M age = 7.93 years, SD = 0.64 years). Participants used a computer-based task to judge the hostility of persons (fictitious characters). Adolescents with ID were found to make more polarizing judgments (i.e., either positive or negative, as opposed to moderate judgments) and were more likely to be guided by the opinions of a fictitious peer ingroup (minimal group) compared with adolescents without ID. No such differences were found between adolescents with ID and MA-matched children. The results are discussed in terms of scientific and practical implications.