Age differences in Neural Activation to Face Trustworthiness: Voxel Pattern and Activation Level Assessments.

Judgment of trustworthiness is an important social ability. Many studies show neural activation differences to variations in face trustworthiness in brain reward regions. A previously published analysis of the present fMRI data showed that older adults' (OA) reward region activation responded significantly to trustworthiness in a set of older and younger faces, whereas younger adults' (YA) activation did not-a finding inconsistent with studies that used only younger faces. We hypothesized that voxel pattern analyses would be more sensitive to YA neural responses to trustworthiness in our set of faces, replicating YA neural discrimination in prior literature. Based on evidence for OA neural dedifferentiation, we also hypothesized that voxel pattern analyses would more accurately classify YA than OA neural responses to face trustworthiness. We reanalyzed the data with two pattern classification models and evaluated the models' performance with permutation testing. Voxel patterns discriminated face trustworthiness levels in both YA and OA reward regions, while allowing better classification of face trustworthiness for YA than OA, the reverse of previous results for neural activation levels. The moderation of age differences by analytic method shines a light on the possibility that voxel patterns uniquely index neural representations of the stimulus information content, consistent with findings of impaired representation with age.

Reading the lines in the face: The contribution of angularity and roundness to perceptions of facial anger and joy.

Through 3 studies, we investigated whether angularity and roundness present in faces contributes to the perception of anger and joyful expressions, respectively. First, in Study 1 we found that angry expressions naturally contain more inward-pointing lines, whereas joyful expressions contain more outward-pointing lines. Then, using image-processing techniques in Studies 2 and 3, we filtered images to contain only inward-pointing or outward-pointing lines as a way to approximate angularity and roundness. We found that filtering images to be more angular increased how threatening and angry a neutral face was rated, increased how intense angry expressions were rated, and enhanced the recognition of anger. Conversely, filtering images to be rounder increased how warm and joyful a neutral face was rated, increased the intensity of joyful expressions, and enhanced recognition of joy. Together these findings show that angularity and roundness play a direct role in the recognition of angry and joyful expressions. Given evidence that angularity and roundness may play a biological role in indicating threat and safety in the environment, this suggests that angularity and roundness represent primitive facial cues used to signal threat-anger and warmth-joy pairings. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Dietary dopamine depletion blunts reward network sensitivity to face trustworthiness.

Research demonstrating responsiveness of the neural reward network to face trustworthiness has not assessed whether the effects are mediated by dopaminergic function. We filled this gap in the literature by investigating whether dietary dopamine depletion would blunt the sensitivity of neural activation to faces varying in trustworthiness across reward regions as well as the sensitivity of behavioral responses to those faces. As prolactin release is negatively regulated by dopamine, peripheral prolactin levels confirmed the efficacy of our manipulation. The dopamine depletion manipulation moderated neural activation to face trustworthiness in the amygdala, medial orbital frontal cortex, and ventral medial prefrontal cortex. Control participants ( n=20) showed nonlinear and linear neural activation to face trustworthiness in the amygdala and ventral medial prefrontal cortex, and nonlinear activation in the medial orbital frontal cortex, while depleted participants ( n=20) showed only a linear effect in the amygdala. Controls also showed stronger amygdala activation to high trustworthy faces than depleted participants. In contrast to effects on neural activation, dopamine depletion did not blunt the sensitivity of behavioral ratings. While this is the first study to demonstrate that dopamine depletion blunts the sensitivity of the neural reward system to social stimuli, namely faces varying in trustworthiness, future research should investigate behavioral measures that may be more responsive to dopaminergic effects than face ratings. Such research would shed further light on the possibility that individual differences in dopaminergic function that were simulated by our manipulation influence social interactions with people who vary in facial trustworthiness.

Older adults' neural activation in the reward circuit is sensitive to face trustworthiness.

We examined older adult (OA) and younger adult (YA) neural sensitivity to face trustworthiness in reward circuit regions, previously found to respond to trustworthiness in YA. Interactions of face trustworthiness with age revealed effects exclusive to OA in the amygdala and caudate, and an effect that was not moderated by age in the dorsal anterior cingulate cortex (dACC). OA, but not YA, showed a nonlinear amygdala response to face trustworthiness, with significantly stronger activation response to high than to medium trustworthy faces, and no difference between low and medium or high. This may explain why an earlier study investigating OA amygdala activation to trustworthiness failed to find a significant effect, since only the linear low versus high trustworthiness difference was assessed. OA, but not YA, also showed significantly stronger activation to high than to low trustworthy faces in the right caudate, indicating a positive linear effect, consistent with previous YA research, as well as significantly stronger activation to high than to medium but not low trustworthy faces in the left caudate, indicating a nonlinear effect. Activation in dACC across both age groups showed a positive linear effect consistent with previous YA research. Finally, OA rated the faces as more trustworthy than did YA across all levels of trustworthiness. Future research should examine whether the null effects for YA were due to our inclusion of older faces. Research also should investigate possible implications of our findings for more ecologically valid OA responses to people who vary in facial trustworthiness.

Age Bias in Selection Decisions: The Role of Facial Appearance and Fitness Impressions.

This research examined the impact of facial age appearance on hiring, and impressions of fitness as the underlying mechanism. In two experimental hiring simulations, one with lay persons and one with Human Resource professionals, participants evaluated a chronologically older or younger candidate (as indicated by date of birth and age label) with either younger or older facial age appearance (as indicated by a photograph). In both studies, older-looking candidates received lower hireability ratings, due to less favorable fitness impressions. In addition, Study 1 showed that this age bias was reduced when the candidates provided counter-stereotypic information about their fitness. Study 2 showed that facial age-based discrimination is less prevalent in jobs with less costumer contact (e.g., back office).

Age Differences In Emotion Recognition: Task Demands Or Perceptual Dedifferentiation?

Background/Study Context: Older adults (OA) have consistently shown lower accuracy compared with younger adults (YA) when labeling facial expressions of emotion in multiple choice tasks. However, OA do not show lower accuracy when judging psychological attributes from faces in rating tasks. The authors investigated whether the cognitive demands of multiple choice tasks yields an underestimation of OA emotion recognition ability and whether lower scores by OA in emotion recognition tasks are an instance of age-related dedifferentiated face perception. METHODS: Younger and older adults judged the emotions of faces depicting various expressions using (a) a multiple choice task and (b) a rating task with separate scales for each expression. We computed both accuracy scores and an emotion differentiation index, adapted from previous work on neural activation to different stimulus categories. RESULTS: Lower OA performance in emotion recognition do not reflect the cognitive demands of a multiple choice task, since age differences also were shown when assessing emotion expressions on independent rating scales. An index calculating differentiation of the emotion expressions supported the hypothesis that age differences in emotion recognition accuracy may reflect age-related perceptual dedifferentiation. DISCUSSION: Results are consistent with other evidence for perceptual dedifferentiation in OA, including lower OA performance in face recognition tasks, rating faces more similarly to one another on trait dimensions, and less specificity in neural activation to faces.

First Impressions From Faces.

Although cultural wisdom warns 'don't judge a book by its cover,' we seem unable to inhibit this tendency even though it can produce inaccurate impressions of people's psychological traits and has significant social consequences. One explanation for this paradox is that first impressions of faces overgeneralize our adaptive impressions of categories of people that those faces resemble (including babies, familiar or unfamiliar people, unfit people, emotional people). Research testing these 'overgeneralization' hypotheses elucidates why we form first impressions from faces, what impressions we form, and what cues influence these impressions. This article focuses on commonalities in impressions across diverse perceivers. However, brief attention is given to individual differences in impressions and impression accuracy.

The Older Adult Positivity Effect in Evaluations of Trustworthiness: Emotion Regulation or Cognitive Capacity?

An older adult positivity effect, i.e., the tendency for older adults to favor positive over negative stimulus information more than do younger adults, has been previously shown in attention, memory, and evaluations. This effect has been attributed to greater emotion regulation in older adults. In the case of attention and memory, this explanation has been supported by some evidence that the older adult positivity effect is most pronounced for negative stimuli, which would motivate emotion regulation, and that it is reduced by cognitive load, which would impede emotion regulation. We investigated whether greater older adult positivity in the case of evaluative responses to faces is also enhanced for negative stimuli and attenuated by cognitive load, as an emotion regulation explanation would predict. In two studies, younger and older adults rated trustworthiness of faces that varied in valence both under low and high cognitive load, with the latter manipulated by a distracting backwards counting task. In Study 1, face valence was manipulated by attractiveness (low /disfigured faces, medium, high/fashion models' faces). In Study 2, face valence was manipulated by trustworthiness (low, medium, high). Both studies revealed a significant older adult positivity effect. However, contrary to an emotion regulation account, this effect was not stronger for more negative faces, and cognitive load increased rather than decreased the rated trustworthiness of negatively valenced faces. Although inconsistent with emotion regulation, the latter effect is consistent with theory and research arguing that more cognitive resources are required to process negative stimuli, because they are more cognitively elaborated than positive ones. The finding that increased age and increased cognitive load both enhanced the positivity of trustworthy ratings suggests that the older adult positivity effect in evaluative ratings of faces may reflect age-related declines in cognitive capacity rather than increases in the regulation of negative emotions.

Aging-Related Changes in Decoding Negative Complex Mental States from Faces.

Background/Study Context: Many studies have found age-related declines in emotion recognition, with older adult (OA) deficits strongest for negative emotions. Some evidence suggests that OA also show worse performance in decoding complex mental states. However, no research has investigated whether those deficits are stronger for negative states. METHODS: The authors investigated OA (ages 65-93) and younger adult (YA; ages 18-22) performance on the Reading the Mind in the Eyes Test (RME), a well-validated measure of the ability to decode complex mental states from faces. RESULTS: The authors replicated findings showing OA deficits in this task. Using a multilevel logistic model, the authors found that the poorer performance of OA was due to worse performance on items for which a negative state was the correct answer. When analyzing each age group separately, OA scored worse on negative than positive items, whereas YA performance did not vary as a function of item valence. These age differences on the RME could not be explained by differences in lower-level visual function. CONCLUSION: These findings show that previously documented OA deficits in perceiving basic negative emotional expressions are also present in reading complex mental states.

Age Differences in the Differentiation of Trait Impressions From Faces.

OBJECTIVES: We investigated whether evidence that older adults (OA) show less differentiation of visual stimuli than younger adults (YA) extends to trait impressions from faces and effects of face age. We also examined whether age differences in mood, vision, or cognition-mediated differentiation differences. Finally, we investigated whether age differences in trait differentiation mediated differences in impression positivity. METHOD: We used a differentiation index adapted from previous work on stereotyping to assess OA and YA likelihood of assigning different faces to different levels on trait scales. We computed scores for ratings of older and younger faces' competence, health, hostility, and untrustworthiness. RESULTS: OA showed less differentiated trait ratings than YA. Measures of mood, vision, and cognition did not mediate these rater age differences. Hostility was differentiated more for younger than older faces, while health was differentiated more for older faces, but only by OA. Age differences in differentiation mediated age differences in impression positivity. DISCUSSION: Less differentiation of trait impressions from faces in OA is consistent with previous evidence for less differentiation in face and emotion recognition. Results indicated that that age-related dedifferentiation does not reflect narrow changes in visual function. They also provide a novel explanation for OA positivity effects.

The influence of political candidates' facial appearance on older and younger adults' voting choices and actual electoral success.

Younger adults (YA) judgments of political candidates' competence from facial appearance accurately predict electoral success. Whether this is true for older adults (OA) has not been investigated despite the fact that OA are more likely to vote than YA and may respond differently to particular facial qualities. We examined whether OA and YA ratings of competence, trustworthiness, attractiveness, and babyfaceness of opposing candidates in US Senate elections independently predicted their own vote choices and actual election outcomes. OA and YA ratings of attractiveness, competence, and trustworthiness positively predicted their choices, but the effect of competence was weaker for OA. Babyfaceness negatively predicted OA, but not YA, choices. OA and YA competence ratings equally predicted the actual election winners, while OA, but not YA, attractiveness ratings did so. Trustworthy and babyface ratings did not predict actual winners. These findings have implications for understanding age differences in candidate preferences and the prediction of election outcomes.

Face Shape and Behavior: Implications of Similarities in Infants and Adults.

We investigated conceptual overlap between literature demonstrating links between adult facial width-to-height ratio (FWHR) and behavior and that demonstrating links between infant FWHR and temperament by investigating whether babyfaceness is associated with FWHR and behavior at both ages. Babyfaceness was positively correlated with FWHR in both infants and adults. Babyfaceness also was correlated with an infant temperament that is a precursor of bolder behavior in childhood and adulthood, just as a broader infant FWHR was previously shown to be. These results call into question existing explanations for relationships between facial appearance and adult assertive or aggressive behavior. Previously, behavioral correlates of adult FWHR have been attributed to influences of pubertal testosterone, and correlates of adult babyfaceness have been attributed to compensation for undesirable stereotypes. Our findings indicate that the pre-natal developmental influences required to explain appearance-temperament relationships in infancy also should be considered as explanations for appearance-behavior relationships in adulthood.

Ailing voters advance attractive congressional candidates.

Among many benefits of facial attractiveness, there is evidence that more attractive politicians are more likely to be elected. Recent research found this effect to be most pronounced in congressional districts with high disease threat-a result attributed to an adaptive disease avoidance mechanism, whereby the association of low attractiveness with poor health is particularly worrisome to voters who feel vulnerable to disease. We provided a more direct test of this explanation by examining the effects of individuals' own health and age. Supporting a disease avoidance mechanism, less healthy participants showed a stronger preference for more attractive contenders in U.S. Senate races than their healthier peers, and this effect was stronger for older participants, who were generally less healthy than younger participants. Stronger effects of health for older participants partly reflected the absence of positive bias toward attractive candidates among the healthiest, suggesting that healthy older adults may be unconcerned about disease threat or sufficiently wise to ignore attractiveness.

Older and younger adults' accuracy in discerning health and competence in older and younger faces.

We examined older and younger adults' accuracy judging the health and competence of faces. Accuracy differed significantly from chance and varied with face age but not rater age. Health ratings were more accurate for older than younger faces, with the reverse for competence ratings. Accuracy was greater for low attractive younger faces, but not for low attractive older faces. Greater accuracy judging older faces' health was paralleled by greater validity of attractiveness and looking older as predictors of their health. Greater accuracy judging younger faces' competence was paralleled by greater validity of attractiveness and a positive expression as predictors of their competence. Although the ability to recognize variations in health and cognitive ability is preserved in older adulthood, the effects of face age on accuracy and the different effects of attractiveness across face age may alter social interactions across the life span.

The attractiveness halo effect and the babyface stereotype in older and younger adults: similarities, own-age accentuation, and older adult positivity effects.

UNLABELLED: BACKGROUND/STUDY CONTEXT: Two well-documented phenomena in person perception are the attractiveness halo effect (more positive impressions of more attractive people), and the babyface stereotype (more childlike impressions of more babyfaced people), shown by children, young adults (YA), and people from diverse cultures. This is the first study to systematically investigate these face stereotypes in older adults (OA) and to compare effects for younger and older adult faces. METHODS: YA and OA judges rated competence, health, hostility, untrustworthiness, attractiveness, and babyfaceness of older and younger neutral expression faces. Multilevel modeling assessed effects of rater age and face age on appearance stereotypes. RESULTS: Like YA, OA showed both the attractiveness halo effect and the babyface stereotype. However, OA showed weaker effects of attractiveness on impressions of untrustworthiness, and only OA associated higher babyfaceness with greater competence. There also was own-age accentuation, with both OA and YA showing stronger face stereotypes for faces closer to their own age. Age differences in the strength of the stereotypes reflected an OA positivity effect shown in more influence of positive facial qualities on impressions or less influence of negative ones, rather than vice versa. CONCLUSION: OA own-age biases, previously shown in emotion, age, and identity recognition, and OA positivity effects, previously revealed in attention, memory, and social judgments, also influence age differences in the strength and content of appearance stereotypes. Future research should assess implications of these results for age-related differences in susceptibility to appearance biases that YA have shown in socially significant domains, such as judicial and personnel decisions.

Age similarities in recognizing threat from faces and diagnostic cues.

BACKGROUND: Previous research indicates that younger adults (YA) can identify men's tendency to be aggressive based merely on their neutral expression faces. We compared older adults (OA) and YA accuracy and investigated contributing facial cues. METHOD: In Study 1, YA and OA rated the aggressiveness of young men depicted in facial photographs in a control, distraction, or accuracy motivation condition. In Study 2, YA and OA rated how angry, attractive, masculine, and babyfaced the men looked in addition to rating their aggressiveness. These measures plus measured facial width-to-height ratio (FWHR) were used to examine cues to aggressiveness. RESULTS: Accuracy coefficients, calculated by correlating rated aggressiveness with the men's previously measured actual aggressiveness, were significant and equal for OA and YA. Accuracy was not moderated by distraction or accuracy motivation, suggesting automatic processing. A greater FWHR, lower attractiveness, and higher masculinity independently influenced rated aggressiveness by both age groups and also were valid cues to actual aggressiveness. DISCUSSION: Despite previous evidence for positivity biases in OA, they can be just as accurate as YA when it comes to discerning actual differences in the aggressiveness of young men.

Older Adults' Trait Impressions of Faces Are Sensitive to Subtle Resemblance to Emotions.

Younger adults (YA) attribute emotion-related traits to people whose neutral facial structure resembles an emotion (emotion overgeneralization). The fact that older adults (OA) show deficits in accurately labeling basic emotions suggests that they may be relatively insensitive to variations in the emotion resemblance of neutral expression faces that underlie emotion overgeneralization effects. On the other hand, the fact that OA, like YA, show a 'pop-out' effect for anger, more quickly locating an angry than a happy face in a neutral array, suggests that both age groups may be equally sensitive to emotion resemblance. We used computer modeling to assess the degree to which neutral faces objectively resembled emotions and assessed whether that resemblance predicted trait impressions. We found that both OA and YA showed anger and surprise overgeneralization in ratings of danger and naiveté, respectively, with no significant differences in the strength of the effects for the two age groups. These findings suggest that well-documented OA deficits on emotion recognition tasks may be more due to processing demands than to an insensitivity to the social affordances of emotion expressions.

Older and younger adults' first impressions from faces: similar in agreement but different in positivity.

People readily form first impressions from faces, with consensual judgments that have significant social consequences. Similar impressions are shown by children, young adults (YA), and people from diverse cultures. However, this is the first study to systematically investigate older adults' (OA) impressions. OA and YA showed similar levels of within-age agreement in their impressions of competence, health, hostility, and trustworthiness. Both groups also showed stronger within- than between-age agreement. Consistent with other evidence for age-related increases in positivity, OA showed more positive impressions of the health, hostility, and trustworthiness of faces. These effects tended to be strongest for the most negatively valenced faces, suggesting that they derive from OA lesser processing of negative cues rather than greater processing of positive cues. An own-age bias in impressions was limited to greater OA positivity in impressions of the hostility of older faces, but not younger ones. Although OA and YA differed in vision and executive function, only OA slower processing speed contributed to age differences in impression positivity. Positivity effects in OA have not been previously linked to processing speed, and research investigating possible explanations for this effect would be worthwhile.

Skin and bones: the contribution of skin tone and facial structure to racial prototypicality ratings.

Previous research reveals that a more 'African' appearance has significant social consequences, yielding more negative first impressions and harsher criminal sentencing of Black or White individuals. This study is the first to systematically assess the relative contribution of skin tone and facial metrics to White, Black, and Korean perceivers' ratings of the racial prototypicality of faces from the same three groups. Our results revealed that the relative contribution of metrics and skin tone depended on both perceiver race and face race. White perceivers' racial prototypicality ratings were less responsive to variations in skin tone than were Black or Korean perceivers' ratings. White perceivers ratings' also were more responsive to facial metrics than to skin tone, while the reverse was true for Black perceivers. Additionally, across all perceiver groups, skin tone had a more consistent impact than metrics on racial prototypicality ratings of White faces, with the reverse for Korean faces. For Black faces, the relative impact varied with perceiver race: skin tone had a more consistent impact than metrics for Black and Korean perceivers, with the reverse for White perceivers. These results have significant implications for predicting who will experience racial prototypicality biases and from whom.