Evidence for a kernel of truth in children's facial impressions of children's niceness, but not shyness.

Adults teach children not to "judge a book by its cover." However, adults make rapid judgments of character from a glance at a child's face. These impressions can be modestly accurate, suggesting that adults may be sensitive to valid signals of character in children's faces. However, it is not clear whether such sensitivity requires decades of social experience, in line with the development of other face-processing abilities (e.g., facial emotion recognition), or whether this sensitivity emerges relatively early, in childhood. An important theoretical question therefore, is whether or not children's impressions are at all accurate. Here, we examined the accuracy in children's impressions of niceness and shyness from children's faces. Children (aged 7-12 years, ∼90% Caucasian) and adults rated 84 unfamiliar children's faces (aged 4-11 years, 48 female, ∼80% Caucasian) for niceness (Study 1) or shyness (Study 2). To measure accuracy, we correlated facial impressions with parental responses to well-established questionnaires about the actual niceness/shyness of those children in the images. Overall, children and adults formed highly similar niceness (r = .94) and shyness (r = .84) impressions. Children also showed mature impression accuracy: Children and adults formed modestly accurate niceness impressions, across different images of the same child's face. Neither children nor adults showed evidence for accurate shyness impressions. Together, these results suggest that children's impressions are relatively mature by middle childhood. Furthermore, these results demonstrate that any mechanisms driving accurate niceness impressions are in place by 7 years, and potentially before. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Beyond Likert ratings: Improving the robustness of developmental research measurement using best-worst scaling.

Some of the 'best practice' approaches to ensuring reproducibility of research can be difficult to implement in the developmental and clinical domains, where sample sizes and session lengths are constrained by the practicalities of recruitment and testing. For this reason, an important area of improvement to target is the reliability of measurement. Here we demonstrate that best-worst scaling (BWS) provides a superior alternative to Likert ratings for measuring children's subjective impressions. Seventy-three children aged 5-6 years rated the trustworthiness of faces using either Likert ratings or BWS over two sessions. Individual children's ratings in the BWS condition were significantly more consistent from session 1 to session 2 than those in the Likert condition, a finding we also replicate with a large adult sample (N = 72). BWS also produced more reliable ratings at the group level than Likert ratings in the child sample. These findings indicate that BWS is a developmentally appropriate response format that can deliver substantial improvements in reliability of measurement, which can increase our confidence in the robustness of findings with children.

Adults' facial impressions of children's niceness, but not shyness, show modest accuracy.

Lay wisdom warns against "judging a book by its cover." However, facial first impressions influence people's behaviour towards others, so it is critical that we understand whether these impressions are at all accurate. Understanding impressions of children's faces is particularly important because these impressions can have social consequences during a crucial time of development. Here, we examined the accuracy of two traits that capture the most variance in impressions of children's faces, niceness and shyness. We collected face images and parental reports of actual niceness/shyness for 86 children (4-11 years old). Different images of the same person can lead to different impressions, and so we employed a novel approach by obtaining impressions from five images of each child. These images were ambient, representing the natural variability in faces. Adult strangers rated the faces for niceness (Study 1) or shyness (Study 2). Niceness impressions were modestly accurate for different images of the same child, regardless of whether these images were presented individually or simultaneously as a group. Shyness impressions were not accurate, for images presented either individually or as a group. Together, these results demonstrate modest accuracy in adults' impressions of niceness, but not shyness, from children's faces. Furthermore, our results reveal that this accuracy can be captured by images which contain natural face variability, and holds across different images of the same child's face. These results invite future research into the cues and causal mechanisms underlying this link between facial impressions of niceness and nice behaviour in children.

Individual differences in trust evaluations are shaped mostly by environments, not genes.

People evaluate a stranger's trustworthiness from their facial features in a fraction of a second, despite common advice "not to judge a book by its cover." Evaluations of trustworthiness have critical and widespread social impact, predicting financial lending, mate selection, and even criminal justice outcomes. Consequently, understanding how people perceive trustworthiness from faces has been a major focus of scientific inquiry, and detailed models explain how consensus impressions of trustworthiness are driven by facial attributes. However, facial impression models do not consider variation between observers. Here, we develop a sensitive test of trustworthiness evaluation and use it to document substantial, stable individual differences in trustworthiness impressions. Via a twin study, we show that these individual differences are largely shaped by variation in personal experience, rather than genes or shared environments. Finally, using multivariate twin modeling, we show that variation in trustworthiness evaluation is specific, dissociating from other key facial evaluations of dominance and attractiveness. Our finding that variation in facial trustworthiness evaluation is driven mostly by personal experience represents a rare example of a core social perceptual capacity being predominantly shaped by a person's unique environment. Notably, it stands in sharp contrast to variation in facial recognition ability, which is driven mostly by genes. Our study provides insights into the development of the social brain, offers a different perspective on disagreement in trust in wider society, and motivates new research into the origins and potential malleability of face evaluation, a critical aspect of human social cognition.

An objective and reliable electrophysiological marker for implicit trustworthiness perception.

Trustworthiness is assumed to be processed implicitly from faces, despite the fact that the overwhelming majority of research has only involved explicit trustworthiness judgements. To answer the question whether or not trustworthiness processing can be implicit, we apply an electroencephalography fast periodic visual stimulation (FPVS) paradigm, where electrophysiological cortical activity is triggered in synchrony with facial trustworthiness cues, without explicit judgements. Face images were presented at 6 Hz, with facial trustworthiness varying at 1 Hz. Significant responses at 1 Hz were observed, indicating that differences in the trustworthiness of the faces were reflected in the neural signature. These responses were significantly reduced for inverted faces, suggesting that the results are associated with higher order face processing. The neural responses were reliable, and correlated with explicit trustworthiness judgements, suggesting that the technique is capable of picking up on stable individual differences in trustworthiness processing. By demonstrating neural activity associated with implicit trustworthiness judgements, our results contribute to resolving a key theoretical debate. Moreover, our data show that FPVS is a valuable tool to examine face processing at the individual level, with potential application in pre-verbal and clinical populations who struggle with verbalization, understanding or memory.

Appearance-based trust processing in schizophrenia.

OBJECTIVES: Schizophrenia is characterized by impaired social interactions and altered trust. In the general population, trust is often based on facial appearance, with limited validity but enormous social consequences. The aim was to examine trust processing in schizophrenia and specifically to examine how people with schizophrenia use facial appearance as well as actual partner fairness to guide trusting decisions. DESIGN: An experimental economic game study. METHODS: Here, we tested how patients with schizophrenia and control participants (each N = 24) use facial trustworthiness appearance and partner fairness behaviour to guide decisions in a multi-round Trust Game. In the Trust Game, participants lent money to 'partners' whose facial appearance was either untrustworthy or trustworthy, and who either played fairly or unfairly. Clinical symptoms were measured as well as explicit trustworthiness impressions. RESULTS: Overall, the patients with schizophrenia showed unimpaired explicit facial trustworthiness impressions and unimpaired facial appearance biases in the Trust Game. Crucially, patients and controls significantly differed so that the patients with schizophrenia did not learn to discriminate in the Trust Game based on actual partner fairness, unlike control participants. CONCLUSION: A failure to discriminate trust has important implications for everyday functioning in schizophrenia, as forming accurate trustworthiness beliefs is an essential social skill. Critically, without relying on more valid trust cues, people with schizophrenia may be especially susceptible to the misleading effect of appearance when making trusting decisions. PRACTITIONER POINTS: Findings People with schizophrenia made very similar facial trustworthiness impressions to healthy controls and also used facial appearance to guide trust decisions similarly to controls. However, the patient group were less able to explicitly distinguish between fair and unfair partners based on their behaviour compared with the control group. Moreover, people with schizophrenia failed to use actual partner fairness to guide their financial decisions in the Trust Game, unlike controls, and this impairment was specific to a social task. People with schizophrenia may be particularly reliant on facial appearance when trusting others, as they may struggle to incorporate more valid trustworthiness information in their decision-making, such as actual partner fairness.

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.

Are expression aftereffects fully explained by tilt adaptation?

Facial expressions are used as critical social cues in everyday life. Adaptation to expressions causes expression aftereffects. These aftereffects are thought to reflect the operation of face-selective neural mechanisms, and are used by researchers to investigate the nature of those mechanisms. However, recent evidence suggests that expression aftereffects could be at least partially explained by the inheritance of lower-level tilt adaptation through the visual hierarchy. We investigated whether expression aftereffects could be entirely explained by tilt adaptation. Participants completed an expression adaptation task in which we controlled for the influence of tilt by changing the orientation of the adaptor relative to the test stimuli. Although tilt adaptation appeared to make some contribution to the expression aftereffect, robust expression aftereffects still remained after minimizing tilt inheritance, indicating that expression aftereffects cannot be fully explained by tilt adaptation. There was also significant reduction in the expression aftereffects after inverting the adapting face, providing evidence that face-selective processing is involved in these aftereffects.

Positive sequential dependency for face attractiveness perception.

Recent findings from several groups have demonstrated that visual perception at a given moment can be biased toward what was recently seen. This is true both for basic visual attributes and for more complex representations, such as face identity, gender, or expression. This assimilation to the recent past is a positive serial dependency, similar to a temporal averaging process that capitalizes on short-term correlations in visual input to reduce noise and boost perceptual continuity. Here we examine serial dependencies in face perception using a simple attractiveness rating task and a rapid series of briefly presented face stimuli. In a series of three experiments, our results confirm a previous report that face attractiveness exhibits a positive serial dependency. This intertrial effect is not only determined by face attractiveness on the previous trial, but also depends on the faces shown up to five trials back. We examine the effect of stimulus presentation duration and find that stimuli as brief as 56 ms produce a significant positive dependency similar in magnitude to that produced by stimuli presented for 1,000 ms. We observed stronger positive dependencies between same-gender faces, and found a task dependency: Alternating gender discrimination trials with attractiveness rating trials produced no serial dependency. In sum, these findings show that a perception-stabilizing assimilation effect operates in face attractiveness perception that is task dependent and is acquired surprisingly quickly.

Best-worst scaling improves measurement of first impressions.

A common goal in psychological research is the measurement of subjective impressions, such as first impressions of faces. These impressions are commonly measured using Likert ratings. Although these ratings are simple to administer, they are associated with response issues that can limit reliability. Here we examine best-worst scaling (BWS), a forced-choice method, as a potential alternative to Likert ratings for measuring participants' facial first impressions. We find that at the group level, BWS scores correlated almost perfectly with Likert scores, indicating that the two methods measure the same impressions. However, at the individual participant level BWS outperforms Likert ratings, both in terms of ability to predict preferences in a third task, and in terms of test-retest reliability. These benefits highlight the power of BWS, particularly for use in individual differences research.

Expression Recognition Difficulty Is Associated with Social But Not Attention-to-Detail Autistic Traits and Reflects Both Alexithymia and Perceptual Difficulty.

Autistic people often show difficulty with facial expression recognition. However, the degree of difficulty varies widely, which might reflect varying symptom profiles. We examined three domains of autistic traits in the typical population and found that more autistic-like social skills were associated with greater difficulty labelling expressions, and more autistic-like communication was associated with greater difficulty labelling and perceptually discriminating between expressions. There were no associations with autistic-like attention to detail. We also found that labelling, but not perceptual, difficulty was mediated by alexithymia. We found no evidence that labelling or perceptual difficulty was mediated by weakened adaptive coding. Results suggest expression recognition varies between the sub-clinical expressions of autistic symptom domains and reflects both co-occurring alexithymia and perceptual difficulty.

Sexual unfaithfulness can be judged with some accuracy from men's but not women's faces.

We routinely make judgements of trustworthiness from the faces of others. However, the accuracy of such judgements remains contentious. An important context for trustworthiness judgements is sexual unfaithfulness. Accuracy in sexual unfaithfulness judgements may be adaptive for avoiding reproductive costs associated with having an unfaithful partner. Indeed, emerging studies suggest that women, and to a lesser degree, men, show above-chance accuracy in judging sexual unfaithfulness from opposite-sex faces. In the context of mate guarding, it is important not only to assess the likelihood of a partner defecting, but also to detect same-sex poachers. Therefore, here, we examine whether individuals can also judge sexual unfaithfulness (self-reported cheating and poaching behaviour) from same-sex faces. We found above-chance accuracy in judgements of unfaithfulness from same-sex faces in men but not women. Conversely, we found above-chance accuracy for opposite-sex faces in women but not men. Therefore, both men and women showed above-chance accuracy, but only for men's, and not women's, faces. Raters were making accurate (above-chance) judgements of unfaithfulness from men's faces using facial masculinity, a well-established signal of propensity to adopt short-term mating strategies. In summary, we found above-chance accuracy in impressions of unfaithfulness from men's faces. Although very modest, the level of accuracy could nevertheless have biological significance as an evolved adaptation for identifying potential cheaters/poachers.

Testing the functional basis of first impressions: Dimensions for children's faces are not the same as for adults' faces.

Despite warnings not to "judge a book by its cover," people rapidly form facial impressions. In Oosterhof and Todorov's (2008) two-dimensional model of facial impressions, trustworthiness, and dominance underlie impressions and primarily function to signal the potential threat of others. Here, we test a key assumption of these models, namely that these dimensions are functional, by evaluating whether the adult-face dimensions apply to young children's faces. Although it may be functional for adults to judge adult faces on dimensions that signal threat, adults associate different social goals with children, and these goals are likely to impact the impressions adults make of such faces. Thus, a functional approach would predict that the dimensions for children's faces are not threat focused. In Studies 1 and 2, we build a data-driven model of Caucasian adults' impressions of Caucasian children's faces, finding evidence for two dimensions. The first dimension, niceness, is similar (although not identical) to the adult dimension of trustworthiness. However, we find a second dimension, shyness, that is clearly dissociable from dominance (Study 3), and critically, is not focused on threat. We demonstrate that adults are sensitive to subtle facial manipulations of these dimensions (Studies 4 and 5) and that these impressions impact adults' behavioral expectations of children (Study 6). Finally, we show that niceness and shyness dimensions generalize to an independent sample of ambient images, demonstrating their robustness (Study 7). Our results suggest that social goals have the power to drive functional impressions and highlight the flexibility of our visual system when forming such inferences. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

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.

Adaptation to dynamic faces produces face identity aftereffects.

Face aftereffects are well established for static stimuli and have been used extensively as a tool for understanding the neural mechanisms underlying face recognition. It has also been argued that adaptive coding, as demonstrated by face aftereffects, plays a functional role in face recognition by calibrating our face norms to reflect current experience. If aftereffects tap high-level perceptual mechanisms that are critically involved in everyday face recognition then they should also occur for moving faces. Here we asked whether face identity aftereffects can be induced using dynamic adaptors. The face identity aftereffect occurs when adaptation to a particular identity (e.g., Dan) biases subsequent perception toward the opposite identity (e.g., antiDan). We adapted participants to video of real faces that displayed either rigid, non-rigid, or no motion and tested for aftereffects in static antifaces. Adapt and test stimuli differed in size, to minimize low-level adaptation. Aftereffects were found in all conditions, suggesting that face identity aftereffects tap high-level mechanisms important for face recognition. Aftereffects were not significantly reduced in the motion conditions relative to the static condition. Overall, our results support the view that face aftereffects reflect adaptation of high-level mechanisms important for real-world face recognition in which faces are moving.

Impressions of sexual unfaithfulness and their accuracy show a degree of universality.

Forming accurate impressions of others' trustworthiness is a critical social skill, with faithfulness representing a key aspect of trust in sexual relationships. Interestingly, there is evidence for a small degree of accuracy in facial impressions of sexual unfaithfulness. Theoretical accounts suggest that these impressions may function to help with partner selection, and may be universal. If so, impressions should be similar for perceivers from different cultures and accuracy should not be limited to own-race faces. We tested these predictions by asking Caucasian and Asian women to judge the likelihood of unfaithfulness from the faces of Caucasian males whose past sexual history was known. In two studies we found high cross-cultural agreement in these impressions, consistent with universality in the impressions themselves. In Study 1, we found an other-race effect in impression accuracy, with significantly less accurate cross-race impressions by Asian women than own-race impressions by Caucasian women. Asian women showed no accuracy. Interestingly, in Study 2, Asian women who had grown up in the West showed small but significant accuracy in their impressions, with no other-race effect. Results are consistent with a degree of universality in the accuracy of this important aspect of social perception, provided that perceivers have experience with the faces being assessed.

Perceptual experience shapes our ability to categorize faces by national origin: A new other-race effect.

People are better at recognizing own-race than other-race faces. This other-race effect has been argued to be the result of perceptual expertise, whereby face-specific perceptual mechanisms are tuned through experience. We designed new tasks to determine whether other-race effects extend to categorizing faces by national origin. We began by selecting sets of face stimuli for these tasks that are typical in appearance for each of six nations (three Caucasian, three Asian) according to people from those nations (Study 1). Caucasian and Asian participants then categorized these faces by national origin (Study 2). Own-race faces were categorized more accurately than other-race faces. In contrast, Asian American participants, with more extensive other-race experience than the first Asian group, categorized other-race faces better than own-race faces, demonstrating a reversal of the other-race effect. Therefore, other-race effects extend to the ability to categorize faces by national origin, but only if participants have greater perceptual experience with own-race, than other-race faces. Study 3 ruled out non-perceptual accounts by showing that Caucasian and Asian faces were sorted more accurately by own-race than other-race participants, even in a sorting task without any explicit labelling required. Together, our results demonstrate a new other-race effect in sensitivity to national origin of faces that is linked to perceptual expertise.

Beyond opponent coding of facial identity: Evidence for an additional channel tuned to the average face.

Face identity can be represented in a multidimensional space centered on the average. It has been argued that the average acts as a perceptual norm, with the norm coded implicitly by balanced activation in pairs of channels that respond to opposite extremes of face dimensions (two-channel model). In Experiment 1 we used face identity aftereffects to distinguish this model from a narrow-band multichannel model with no norm. We show that as adaptors become more extreme, aftereffects initially increase sharply and then plateau. Crucially there is no decrease, ruling out narrow-band multichannel coding, but consistent with a two-channel norm-based model. However, these results leave open the possibility that there may be a third channel, tuned explicitly to the norm (three-channel model). In Experiment 2 we show that alternating adaptation widens the range identified as the average whereas adaptation to the average narrows the range, consistent with the three-channel model. Explicit modeling confirmed the three-channel model as the best fit for the combined data from both experiments. However, a two-channel model with decision criteria allowed to vary between adapting conditions, also provided a very good fit. These results support opponent, norm-based coding of face identity with additional explicit coding of the norm. (PsycINFO Database Record

The average facial expression of a crowd influences impressions of individual expressions.

People can accurately assess the "mood of a crowd" by rapidly extracting the average intensity of all the individual expressions, when the crowd consists of a set of faces comprising different expressions of the same individual. Here, we investigate the processes involved when people judge the expression intensity of individual faces that appear in the context of a more naturalistic crowd of different individuals' faces. We show that judgments of the intensity of happy and angry expressions for individual faces are biased toward the group mean expression intensity, even when the faces are all different individuals. In a second experiment, we demonstrate that this bias is not due to a generic tendency to endorse intermediate intensity expressions more frequently than more extreme intensity expressions. Together, these findings suggest that people integrate ensemble information about the group average expression when they make judgments of individual faces' expressions. (PsycINFO Database Record