Adult Perceptions of Positive and Negative Infant Emotional Expressions

Adults' perceptions provide information about the emotional meaning of infant facial expressions. This study asks whether similar facial movements influence adult perceptions of emotional intensity in both infant positive (smile) and negative (cry face) facial expressions. Ninety‐five college students rated a series of naturally occurring and digitally edited images of infant facial expressions. Naturally occurring smiles and cry faces involving the co‐occurrence of greater lip movement, mouth opening, and eye constriction, were rated as expressing stronger positive and negative emotion, respectively, than expressions without these 3 features. Ratings of digitally edited expressions indicated that eye constriction contributed to higher ratings of positive emotion in smiles (i.e., in Duchenne smiles) and greater eye constriction contributed to higher ratings of negative emotion in cry faces. Stronger mouth opening contributed to higher ratings of arousal in both smiles and cry faces. These findings indicate a set of similar facial movements are linked to perceptions of greater emotional intensity, whether the movements occur in positive or negative infant emotional expressions. This proposal is discussed with reference to discrete, componential, and dynamic systems theories of emotion.     

Effects of Social Anxiety on Emotional Mimicry and Contagion: Feeling Negative,but Smiling Politely

Socially anxiety may be related to a different pattern of facial mimicry and contagion of others’ emotions. We report two studies in which participants with different levels of social anxiety reacted to others’ emotional displays, either shown on a computer screen (Study 1) or in an actual social interaction (Study 2). Study 1 examined facial mimicry and emotional contagion in response to displays of happiness, anger, fear, and contempt. Participants mimicked negative and positive emotions to some extent, but we found no relation between mimicry and the social anxiety level of the participants. Furthermore, socially anxious individuals were more prone to experience negative emotions and felt more irritated in response to negative emotion displays. In Study 2, we found that social anxiety was related to enhanced mimicry of smiling, but this was only the case for polite smiles and not for enjoyment smiles. These results suggest that socially anxious individuals tend to catch negative emotions from others, but suppress their expression by mimicking positive displays. This may be explained by the tendency of socially anxious individuals to avoid conflict or rejection.     

Quantifying Facial Expression Synchrony in Face-To-Face Dyadic Interactions: Temporal Dynamics of Simultaneously Recorded Facial EMG Signals

Human social interaction is enriched with synchronous movement which is said to be essential to establish interactional flow. One commonly investigated phenomenon in this regard is facial mimicry, the tendency of humans to mirror facial expressions. Because studies investigating facial mimicry in face-to-face interactions are lacking, the temporal dynamics of facial mimicry remain unclear. We therefore developed and tested the suitability of a novel approach to quantifying facial expression synchrony in face-to-face interactions: windowed cross-lagged correlation analysis (WCLC) for electromyography signals. We recorded muscle activations related to smiling (Zygomaticus Major) and frowning (Corrugator Supercilii) of two interaction partners simultaneously in 30 dyadic affiliative interactions. We expected WCLC to reliably detect facial expression synchrony above chance level and, based on previous research, expected the occurrence of rapid synchronization of smiles within 200 ms. WCLC significantly detected synchrony of smiling but not frowning compared to a control condition of chance level synchrony in six different interactional phases (smiling: d _z s = .85–1.11; frowning: d _z s = .01–.30). Synchronizations of smiles between interaction partners predominantly occurred within 1000 ms, with a significant amount occurring within 200 ms. This rapid synchronization of smiles supports the notion of the existence of an anticipated mimicry response for smiles. We conclude that WCLC is suited to quantify the temporal dynamics of facial expression synchrony in dyadic interactions and discuss implications for different psychological research areas.     

Differential Reliance on the Duchenne Marker During Smile Evaluations and Person Judgments

When evaluating the smiles of other people (regarding amusement, authenticity, spontaneity, or intensity), perceivers typically rely on Orbicularis oculi activity that causes wrinkles around a target’s eyes. But does this so-called Duchenne marker also impact more generalized judgments of person characteristics (e.g., regarding a target’s attractiveness, intelligence, dominance, and trustworthiness)? To address this issue, the current study asked participants to provide the above smile evaluations and person judgments for a series of Duchenne and non-Duchenne smiles. The results showed that smile evaluations uniformly increased during Duchenne marker presence. The marker’s effect on person judgments, in contrast, was judgment dependent. While attractiveness, dominance and intelligence ratings showed the expected enhancement, trustworthiness ratings remained unaffected by the facial cue of interest. The findings suggest that the Duchenne marker’s role as a cue of social relevance during target perception depends on the type of person inference under consideration.     

Felt,false, and miserable smiles

Theoretically based distinctions linked to measurable differences in appearance are described for three smiles: felt smiles (spontaneous expressions of positive emotion); false smiles (deliberate attempts to appear as if positive emotion is felt when it isn't); and, miserable smiles (acknowledgements of feeling miserable but not intending to do much about it). Preliminary evidence supports some of the hypotheses about how these three kinds of smile differ.This research was supported by a grant (MH 11976) and a Research Scientist Award (MH 06092) from the National Institute of Mental Health. We are grateful to Maureen O'Sullivan for her suggestions on this report.     

Children’s Nonverbal Displays of Winning and Losing: Effects of Social and Cultural Contexts on Smiles

We examined the effects of social and cultural contexts on smiles displayed by children during gameplay. Eight-year-old Dutch and Chinese children either played a game alone or teamed up to play in pairs. Activation and intensity of facial muscles corresponding to Action Unit (AU) 6 and AU 12 were coded according to Facial Action Coding System. Co-occurrence of activation of AU 6 and AU 12, suggesting the presence of a Duchenne smile, was more frequent among children who teamed up than among children who played alone. Analyses of the intensity of smiles revealed an interaction between social and cultural contexts. Whereas smiles, both Duchenne and non-Duchenne, displayed by Chinese children who teamed up were more intense than those displayed by Chinese children who played alone, the effect of sociality on smile intensity was not observed for Dutch children. These findings suggest that the production of smiles by children in a competitive context is susceptible to both social and cultural factors.     

Infant Smiling Dynamics and Perceived Positive Emotion

To better understand early positive emotional expression, automated software measurements of facial action were supplemented with anatomically based manual coding. These convergent measurements were used to describe the dynamics of infant smiling and predict perceived positive emotional intensity. Over the course of infant smiles, degree of smile strength varied with degree of eye constriction (cheek raising, the Duchenne marker), which varied with degree of mouth opening. In a series of three rating studies, automated measurements of smile strength and mouth opening predicted naïve (undergraduate) observers’ continuous ratings of video clips of smile sequences, as well as naïve and experienced (parent) ratings of positive emotion in still images from the sequences. An a priori measure of smile intensity combining anatomically based manual coding of both smile strength and mouth opening predicted positive emotion ratings of the still images. The findings indicate the potential of automated and fine-grained manual measurements of facial actions to describe the course of emotional expressions over time and to predict perceptions of emotional intensity.     

Effects of Dynamic Attributes of Smiles in Human and Synthetic Faces: A Simulated Job Interview Setting

We examined the effects of the temporal quality of smile displays on impressions and decisions made in a simulated job interview. We also investigated whether similar judgments were made in response to synthetic (Study 1) and human facial stimuli (Study 2). Participants viewed short video excerpts of female interviewees exhibiting dynamic authentic smiles, dynamic fake smiles, or neutral expressions, and rated them with respect to a number of attributes. In both studies, perceivers’ judgments and employment decisions were significantly shaped by the temporal quality of smiles, with dynamic authentic smiles generally leading to more favorable job, person, and expression ratings than dynamic fake smiles or neutral expressions. Furthermore, authentically smiling interviewees were judged to be more suitable and were more likely to be short-listed and selected for the job. The findings show a high degree of correspondence in the effects created by synthetic and human facial stimuli, suggesting that temporal features of smiles similarly influence perceivers’ judgments and decisions across the two types of stimulus.

Comparison of Deliberate and Spontaneous Facial Movement in Smiles and Eyebrow Raises

We investigated movement differences between deliberately posed and spontaneously occurring smiles and eyebrow raises during a videotaped interview that included a facial movement assessment. Using automated facial image analysis, we quantified lip corner and eyebrow movement during periods of visible smiles and eyebrow raises and compared facial movement within participants. As in an earlier study, maximum speed of movement onset was greater in deliberate smiles. Maximum speed and amplitude were greater and duration shorter in deliberate compared to spontaneous eyebrow raises. Asymmetry of movement did not differ within participants. Similar patterns contrasting deliberate and spontaneous movement in both smiles and eyebrow raises suggest a common pattern of signaling for spontaneous facial displays.

How the Experience of Emotion is Modulated by Facial Feedback

The facial feedback hypothesis states that facial actions modulate subjective experiences of emotion. Using the voluntary facial action technique, in which the participants react with instruction induced smiles and frowns when exposed to positive and negative emotional pictures and then rate the pleasantness of these stimuli, four questions were addressed in the present study. The results in Experiment 1 demonstrated a feedback effect because participants experienced the stimuli as more pleasant during smiling as compared to when frowning. However, this effect was present only during the critical actions of smiling and frowning, with no remaining effects after 5 min or after 1 day. In Experiment 2, feedback effects were found only when the facial action (smile/frown) was incongruent with the presented emotion (positive/negative), demonstrating attenuating but not enhancing modulation. Finally, no difference in the intensity of produced feedback effect was found between smiling and frowning, and no difference in feedback effect was found between positive and negative emotions. In conclusion, facial feedback appears to occur mainly during actual facial actions, and primarily attenuate ongoing emotional states.     

Emotion Recognition in Nonverbal Face-to-Face Communication

The perception of emotional facial expressions may activate corresponding facial muscles in the receiver, also referred to as facial mimicry. Facial mimicry is highly dependent on the context and type of facial expressions. While previous research almost exclusively investigated mimicry in response to pictures or videos of emotional expressions, studies with a real, face-to-face partner are still rare. Here we compared facial mimicry of angry, happy, and sad expressions and emotion recognition in a dyadic face-to-face setting. In sender-receiver dyads, we recorded facial electromyograms in parallel. Senders communicated to the receivers—with facial expressions only—the emotions felt during specific personal situations in the past, eliciting anger, happiness, or sadness. Receivers mostly mimicked happiness, to a lesser degree, sadness, and anger as the least mimicked emotion. In actor-partner interdependence models we showed that the receivers’ own facial activity influenced their ratings, which increased the agreement between the senders’ and receivers’ ratings for happiness, but not for angry and sad expressions. These results are in line with the Emotion Mimicry in Context View, holding that humans mimic happy expressions according to affiliative intentions. The mimicry of sad expressions is less intense, presumably because it signals empathy and might imply personal costs. Direct anger expressions are mimicked the least, possibly because anger communicates threat and aggression. Taken together, we show that incidental facial mimicry in a face-to-face setting is positively related to the recognition accuracy for non-stereotype happy expressions, supporting the functionality of facial mimicry.     

Movement Differences between Deliberate and Spontaneous Facial Expressions: Zygomaticus Major Action in Smiling

Previous research suggests differences in lip movement between deliberate and spontaneous facial expressions. We investigated within participant differences between deliberately posed and spontaneously occurring smiles during a directed facial action task. Using automated facial image analysis, we quantified lip corner movement during periods of visible Zygomaticus major activity. Onset and offset speed, amplitude of movement, and offset duration were greater in deliberate smiles. In contrast to previous results, however, lip corner movement asymmetry was not greater in deliberate smiles. Observed characteristics of deliberate and spontaneous smiling may be related to differences in the typical context and purpose of the facial signal. Karen L. Schmidt, Zara Ambadar, Jeffrey F. Cohn, and L. Ian Reed are affiliated with the University of Pittsburgh, Pittsburgh, PA 15260, USA. Jeffrey F. Cohn is also affiliated with the Carnegie Mellon University, Pittsburgh, PA 15260, USA. This research was supported by NIMH Grants MH15279 and 167376 to Karen L. Schmidt, and NIMH Grant MH 51435 to Jeffrey F. Cohn. We gratefully acknowledge the assistance of Adena Zlochower in digitizing videotape used in this analysis and Rachel Levenstein in the analysis of data described in this paper. Address correspondence to Karen L. Schmidt, University of Pittsburgh, 121 University Pl, Pittsburgh, PA 15260, USA; E-mail: kschmidt@pitt.edu     

Gender-based expectancies and observer judgments of smiling

Beliefs about gender differences in smiling were measured by asking college students to rate how much they believed hypothetical women and men smile. Women were believed to smile more than men. Individual differences in this belief did not affect subsequent scoring of smiles, whether scored by counting the number of smiles exhibited by videotaped male and female targets or by rating the amount of smiling exhibited. An expectation about gender differences in smiling was experimentally induced, either that women smile more than men or that there is no gender difference in smiling. This expectation did not affect subsequent scoring of smiles, regardless of scoring method and regardless of whether the expectation was induced as a casual aside or in more formal instructions. In all conditions female targets were observed to smile more than male targets. Rating produced larger target gender effects than counting, but this could have been due to the nature of the rating process rather than observer bias.The authors gratefully acknowledge the assistance of Thomas Leahy and Joe Pieri in data collection, and of Cliff Brown and an anonymous reviewer for their comments on an earlier version of this paper. Miles Patterson served as Action Editor for this article.     

Feel Bad and Keep Steady: Emotional Images and Words and Postural Control during Bipedal Stance

The study investigates effects of emotional pictures and words on Center of Pressure (CoP) whole-body reactions, based on theories of emotional valence and arousal, approach–avoidance theory, freezing in humans, and stimulus type (pictures vs. words). For freezing, the study differentiated between rambling and trembling components of the CoP reaction. We hypothesized that negative versus positive emotional valence caused stronger CoP avoidance, for both emotional pictures and words. In addition, freezing was hypothesized to be evident in the CoP trembling component caused by high emotional arousal. Forty-five students enrolled in a teacher program completed a bipedal assessment on a force plate while watching positive versus negative and high- versus low-arousal pictures and words that had been selected from stimulus lists in a pretest. Participants rated the valence and arousal of all stimuli in a questionnaire, the results of which indicated a relationship between negative valence and high arousal. The force plate data confirm the hypotheses. First, negative stimuli elicited significant avoidance CoP shifts, independent of their arousal, as indicated by t tests. This effect was found for both emotional pictures and words. CoP for positive stimuli did not differ from zero. Second, indicating freezing, the CoP trembling component was increased by high arousal, independent of valence. Freezing was only found for emotional pictures. The study discusses both the CoP avoidance effect with respect to valence and stimulus type, and the value of the trembling analysis for freezing. It closes with an analysis of the methodological limitations and with recommendations for future studies.     

All Smiles are Not Created Equal: Morphology and Timing of Smiles Perceived as Amused, Polite, and Embarrassed/Nervous

We investigated the correspondence between perceived meanings of smiles and their morphological and dynamic characteristics. Morphological characteristics included co-activation of Orbicularis oculi (AU 6), smile controls, mouth opening, amplitude, and asymmetry of amplitude. Dynamic characteristics included duration, onset and offset velocity, asymmetry of velocity, and head movements. Smile characteristics were measured using the Facial Action Coding System (Ekman et al. 2002) and Automated Facial Image Analysis (Cohn and Kanade 2007). Observers judged 122 smiles as amused, embarrassed, nervous, polite, or other. Fifty-three smiles met criteria for classification as perceived amused, embarrassed/nervous, or polite. In comparison with perceived polite, perceived amused more often included AU 6, open mouth, smile controls, larger amplitude, larger maximum onset and offset velocity, and longer duration. In comparison with perceived embarrassed/nervous, perceived amused more often included AU 6, lower maximum offset velocity, and smaller forward head pitch. In comparison with perceived polite, perceived embarrassed/nervous more often included mouth opening and smile controls, larger amplitude, and greater forward head pitch. Occurrence of the AU 6 in perceived embarrassed/nervous and polite smiles questions the assumption that AU 6 with a smile is sufficient to communicate felt enjoyment. By comparing three perceptually distinct types of smiles, we found that perceived smile meanings were related to specific variation in smile morphological and dynamic characteristics.

Temporal Aspects of Facial Displays in Person and Expression Perception: The Effects of Smile Dynamics,Head-tilt,and Gender

Recent work suggests that temporal aspects of facial displays influence the perception of the perceived authenticity of a smile. In the present research, the impact of temporal aspects of smiles on person and expression perception was explored in combination with head-tilt and gender. One hundred participants were shown different types of smiles (slow versus fast onset) in combination with three forms of head-tilt (none, left, or right) exhibited by six computer-generated male and female encoders. The encoders were rated for perceived attractiveness, trustworthiness, dominance, and the smiles were rated for flirtatiousness and authenticity. Slow onset smiles led to more positive evaluations of the encoder and the smiles. Judgments were also significantly influenced by head-tilt and participant and encoder gender, demonstrating the combined effect of all three variables on expression and person perception.

Emotional Empathy as Related to Mimicry Reactions at Different Levels of Information Processing

The hypotheses of this investigation were based on conceiving of facial mimicry reactions in face-to-face interactions as an early automatic component in the process of emotional empathy. Differences between individuals high and low in emotional empathy were investigated. The parameters compared were facial mimicry reactions, as represented by electromyographic (EMG) activity, when individuals were exposed to pictures of angry or happy faces. The present study distinguished between spontaneous facial reactions and facial expressions associated with more controlled or modulated emotions at different information processing levels, first at a preattentive level and then consecutively at more consciously controlled levels: 61 participants were exposed to pictures at three different exposure times (17, 56, and 2350 ms). A significant difference in facial mimicry reactions between high- and low-empathy participants emerged at short exposure times (56 ms), representing automatic, spontaneous reactions, with high-empathy participants showing a significant mimicking reaction. The low-empathy participants did not display mimicking at any exposure time. On the contrary, the low-empathy participants showed, in response to angry faces, a tendency to an elevated activation in the cheek region, which often is associated with smiling.     

Detecting Happiness: Perceiver Sensitivity to Enjoyment and Non-Enjoyment Smiles

The physiognomic distinctions between spontaneous enjoyment smiles and deliberate non-enjoyment smiles provide the social perceiver with a functional, accessible source of information to help regulate social interaction. Two experiments were performed to investigate whether perceivers were sensitive to this information in a contextually meaningful manner. In Experiment 1, participants were asked to judge whether a target individual was happy or not. The results revealed that participants were indeed sensitive to the differences between enjoyment and non-enjoyment smiles. In Experiment 2, participants performed a priming task without any specific instruction to judge emotional state. Neutral expressions, non-enjoyment smiles and enjoyment smiles were employed as primes in a word valence identification task. The results demonstrated a clear trend indicative of perceiver sensitivity. When compared to a the baseline condition of a neutral expression prime, enjoyment but not non-enjoyment smiles facilitated identification of positive words.

The expressive and communicative functions of preschool children's smiles in an achievement-situation

Two studies examined how different social contexts determine whether preschoolers' smiles in an achievement-game serve an expressive function indicating success versus failure experiences and/or a communicative function. Facial behavior was coded with the Facial Action Coding System. Unexpectedly, in Study 1 children (N=19) smiled more often after failure than after success. Study 2 investigated the influence of face-to-face contact with the experimenter on preschoolers' smiles (N=20). However, there were no differences between success and failure, but with face-to-face contact subjects exhibited more smiles than without. Features of the social situation that are supposed to determine the predominance of the communicative or expressive function of a smile are discussed.We gratefully acknowledge the assistance of Detlef Friedrich and Katja Johann in the data collection and Signe Preuschoft in coding and analyzing the data.