Differences between children and adults in the recognition of enjoyment smiles

The authors investigated the differences between 8-year-olds (n=80) and adults (n=80) in recognition of felt versus faked enjoyment smiles by using a newly developed picture set that is based on the Facial Action Coding System. The authors tested the effect of different facial action units (AUs) on judgments of smile authenticity. Multiple regression showed that children base their judgment on AU intensity of both mouth and eyes, with relatively little distinction between the Duchenne marker (AU6 or "cheek raiser") and a different voluntary muscle that has a similar effect on eye aperture (AU7 or "lid tightener"). Adults discriminate well between AU6 and AU7 and seem to use eye-mouth discrepancy as a major cue of authenticity. Bared-teeth smiles (involving AU25) are particularly salient to both groups. The authors propose and discuss an initial developmental model of the smile recognition process.     

Perceptions of Duchenne and non-Duchenne smiles: A meta-analysis

A meta-analysis was conducted to compare perceptions of Duchenne smiles, smiles that include activation of the cheek raiser muscle that creates crow's feet around the eyes, with perceptions of non-Duchenne smiles, smiles without cheek raiser activation. In addition to testing the overall effect, moderator analyses were conducted to test how methodological, stimulus-specific and perceiver-specific differences between studies predicted the overall effect size. The meta-analysis found that, overall, Duchenne smiles and people producing Duchenne smiles are rated more positively (i.e., authentic, genuine, real, attractive, trustworthy) than non-Duchenne smiles and people producing non-Duchenne smiles. The difference between Duchenne and non-Duchenne smiles was greater when the stimuli were videos rather than photographs, when smiles were elicited naturally rather than through posing paradigms and when Duchenne and non-Duchenne smiles were not matched for intensity of the lip corner puller in addition to other perceiver and methodological moderators.     

How sleeping neonates smile

Infants over one month of age tend to produce two types of smiling during especially positive social interactions, Duchenne smiles involving cheek raising and open‐mouth smiles. Little is known, however, about the prevalence, frequency, duration and organization of these smiles among neonates. Twenty‐five full‐term, healthy neonates (12 female) were videotaped during six minutes of sleep. Smiles were identified and analysed using an anatomically based coding system (FACS/Baby FACS). One‐half of the neonates showed bilateral Duchenne smiles. One‐quarter of the neonates showed bilateral Duchenne smiles at a mature level of intensity whose median duration was 1? s. By contrast, open‐mouth bilateral smiles occurred in less than one‐tenth of the sample. The contrast between the more frequent bilateral Duchenne smiles and the less frequent open‐mouth smile is discussed in terms of the early synergistic functioning of facial muscles and contrasted with the smiling patterns of older infants.     

Children's ability to control the facial expression of laughter and smiling: Knowledge and behaviour

A total of 64 children, aged 7 and 10, watched a clown performing three sketches rated as very funny by the children. Two experimental conditions were created by asking half of the participants to suppress their laughter. Facial expressions were videotaped and analysed with FACS. For both ages, the results show a significant shorter duration (but not a lower frequency) of episodes of laughter and Duchenne smiles, and greater frequency of facial control movements in the suppression compared to the free expression group. The detailed results on individual facial action units used to control amusement expressions suggest hypotheses on the nature of the underlying processes. The participants' explicit knowledge of their control strategies was assessed through standardised interviews. Although behavioural control strategies were reported equally frequently by the two age groups, 10-year-olds verbalised more mental control strategies than 7-year-olds. This theoretically expected difference was not related to the actual ability to control facial expression. This result challenges the commonly held assumption that explicit knowledge of control strategies results in a greater ability to execute such control in ongoing social interactions.     

What's in a smile?

In positive social contexts, both adults and older infants show more Duchenne smiling (which involves high cheek raising) than non-Duchenne smiling (which does not). This study compared Duchenne and non-Duchenne smiles in early infancy for clues to their emotional significance. Infants (N = 13) from 1 to 6 months of age were videotaped weekly for 5 min in 208 face-to-face interactions with their mothers. Levels of Duchenne and non-Duchenne smiling were correlated within interactive sessions, and the 2 smiles had similar developmental trajectories. Duchenne smiles were typically preceded by non-Duchenne smiles. The results suggest these frequently contrasted types of smiles occur in similar situations and are often different temporal phases of a continuous emotional process. In contrast to adults, infant Duchenne smiles had longer durations than non-Duchenne smiles, suggesting infant smiling does not fit adult models of emotional functioning.     

Who likes whom? The interaction between perceiver personality and target look

We investigated determinants of liking at zero-acquaintance, focusing on individual differences in perceivers’ reactions to appearance cues. Perceivers (N = 385) viewed portrait photographs of Targets (N = 146). Perceiver’s Agreeableness and Extraversion were uniquely associated with liking targets. Targets who expressed positive emotions, looked relaxed, were physically attractive, and looked healthy and energetic, were the most liked. There were substantial individual differences in how Perceivers were influenced by appearance cues. For instance, Perceivers generally rated targets who displayed non-Duchenne (fake) smiles less favorably than targets who did not smile or targets who displayed Duchenne (authentic) smiles. However, non-Duchenne smiles elicited especially negative ratings from Perceivers high in Neuroticism or Conscientiousness, but not from Perceivers low in Agreeableness.     

The eyes have it: making positive expressions more positive and negative expressions more negative

Facial expressions frequently involve multiple individual facial actions. How do facial actions combine to create emotionally meaningful expressions? Infants produce positive and negative facial expressions at a range of intensities. It may be that a given facial action can index the intensity of both positive (smiles) and negative (cry-face) expressions. Objective, automated measurements of facial action intensity were paired with continuous ratings of emotional valence to investigate this possibility. Degree of eye constriction (the Duchenne marker) and mouth opening were each uniquely associated with smile intensity and, independently, with cry-face intensity. In addition, degree of eye constriction and mouth opening were each unique predictors of emotion valence ratings. Eye constriction and mouth opening index the intensity of both positive and negative infant facial expressions, suggesting parsimony in the early communication of emotion.     

Intensity of smiling and attractiveness as facial signals of trustworthiness in women

Facial attractiveness is associated with a variety of positive social characteristics including trustworthiness. Variations in smiling, such as the appearance of the Duchenne marker and increased intensity of expression, have likewise been linked with positive judgments of trustworthiness. The study investigated the interaction of the effects of models' attractiveness and their smiling intensity on impressions of perceived trustworthiness. Participants rated the attractiveness and expressivity of neutral, low intensity, and high intensity smiling images of 45 women models. These images were also presented to a second group of participants who rated trustworthiness. Repeated measures analysis of covariance of the effects of attractiveness and manipulated smile intensity on trustworthiness indicated a main effect for smile intensity: increased smile intensity was associated with greater trustworthiness. Attractiveness also contributed to rated trustworthiness independently of smiling intensity. Results suggested there is an additional contribution of facial expression in creating social impressions of trustworthiness.     

A preference for genuine smiles following social exclusion

Research indicates that rejected individuals are better than others at discriminating between genuine (Duchenne) and deceptive (non-Duchenne) smiles (i.e., true versus false signals of affiliative opportunity). We hypothesized that rejected individuals would show a greater preference to work with individuals displaying Duchenne versus non-Duchenne smiles. To test this, participants wrote essays about experiences of inclusion, exclusion, or mundane events. They then saw a series of 20 videos of smiling individuals (10 with Duchenne and 10 with non-Duchenne smiles). Participants then indicated how much they would like to work with each target. Analyses revealed that compared to included and control participants, excluded individuals showed a greater preference to work with individuals displaying “real” as opposed to “fake” smiles. This effect was partially mediated by threats to “relational needs” (Williams, 2007) and fully mediated by threats to self-esteem. These results suggest that exclusion yields adaptive responses that could facilitate reconnection with others.     

Emotional expression and heart rate in high-risk infants during the face-to-face/still-face

In infants, eye constriction—the Duchenne marker—and mouth opening appear to index the intensity of both positive and negative facial expressions. We combined eye constriction and mouth opening that co-occurred with smiles and cry-faces (respectively, the prototypic expressions of infant joy and distress) to measure emotional expression intensity. Expression intensity and heart rate were measured throughout the face-to-face/still-face (FFSF) in a sample of infants with prenatal cocaine exposure who were at risk for developmental difficulties. Smiles declined and cry-faces increased in the still-face episode, but the distribution of eye constriction and mouth opening in smiles and cry-faces did not differ across episodes of the FFSF. As time elapsed in the still face episode potential indices of intensity increased, cry-faces were more likely to be accompanied by eye constriction and mouth opening. During cry-faces there were also moderately stable individual differences in the quantity of eye constriction and mouth opening. Infant heart rate was higher during cry-faces and lower during smiles, but did not vary with intensity of expression or by episode. In sum, infants express more intense negative affect as the still-face progresses, but do not show clear differences in expressive intensity between episodes of the FFSF.     

Duchenne smile,emotional experience,and autonomic reactivity: a test of the facial feedback hypothesis

This study examined the modulatory function of Duchenne and non-Duchenne smiles on subjective and autonomic components of emotion. Participants were asked to hold a pencil in their mouth to either facilitate or inhibit smiles and were not instructed to contract specific muscles. Five conditions--namely lips pressing, low-level non-Duchenne smiling, high-level non-Duchenne smiling, Duchenne smiling, and control--were produced while participants watched videoclips that were evocative of positive or negative affect. Participants who displayed Duchenne smiles reported more positive experience when pleasant scenes and humorous cartoons were presented. Furthermore, they tended to exhibit different patterns of autonomic arousal when viewing positive scenes. These results support thefacial feedback hypothesis and suggest that facial feedback has more powerful effects when facial configurations represent valid analogs of basic emotional expressions.     

Affective exchanges between young autistic children and their mothers

This study examined autistic children's social behavior, affect, and use of gaze during naturalistic interactions with their mothers. Sixteen autistic children, 30 to 70 months of age, and 16 normal children, matched on receptive language, participated. Children and their mothers were videotaped during three situations: a free-play period, a more structured period during which communicative demand was made on the child, and a face-to-face interaction. In all three situations, autistic and normal children did not differ in the frequency or duration of gaze at mother's face. In the one condition (face-to-face interaction) during which affective expressions were coded, autistic and normal children also were not found to differ significantly in the frequency or duration of smiles displayed, and neither group displayed frowns. However, autistic children were much less likely than normal children to combine their smiles with eye contact in a single act that conveyed communicative intent. Autistic and normal children were not found to differ in the percentages of smiles they displayed to social versus nonsocial events. However, when autistic children's responses to mother's smiles specifically were examined, it was found that they were much less likely to smile in response to mother's smiles than were normal children. Finally, it was found that mothers o f autistic children displayed fewer smiles and were less likely to smile in response to their children's smiles, when compared with mothers o f normal children. These findings suggest that the autistic child's unusual affective behavior may negatively affect the behavior of others.We wish to thank the children and their mothers who participated in this study, and the staff at Division TEACCH at the University of North Carolina at Chapel Hill for their help in recruiting children for the study. Harriet Reingold generously allowed us to videotape the children in her infant observation laboratory at the University of North Carolina, Chapel Hill. Cathy Lord provided videotapes of some of the autistic children and their mothers. Mary Evers assisted in data collection. Kerry Hogan assisted in the coding of data; her help is gratefully acknowledged. The study was supported by a grant from the University of North Carolina at Chapel Hill.     

Reliable facial muscle activation enhances recognizability and credibility of emotional expression

We tested Ekman's (2003) suggestion that movements of a small number of reliable facial muscles are particularly trustworthy cues to experienced emotion because they tend to be difficult to produce voluntarily. On the basis of theoretical predictions, we identified two subsets of facial action units (AUs): reliable AUs and versatile AUs. A survey on the controllability of facial AUs confirmed that reliable AUs indeed seem more difficult to control than versatile AUs, although the distinction between the two sets of AUs should be understood as a difference in degree of controllability rather than a discrete categorization. Professional actors enacted a series of emotional states using method acting techniques, and their facial expressions were rated by independent judges. The effect of the two subsets of AUs (reliable AUs and versatile AUs) on identification of the emotion conveyed, its perceived authenticity, and perceived intensity was investigated. Activation of the reliable AUs had a stronger effect than that of versatile AUs on the identification, perceived authenticity, and perceived intensity of the emotion expressed. We found little evidence, however, for specific links between individual AUs and particular emotion categories. We conclude that reliable AUs may indeed convey trustworthy information about emotional processes but that most of these AUs are likely to be shared by several emotions rather than providing information about specific emotions. This study also suggests that the issue of reliable facial muscles may generalize beyond the Duchenne smile.     

Smiling in the face of adversity: the interpersonal and intrapersonal functions of smiling

This study examined hypothesized interpersonal and intrapersonal functions of smiling in positive and negative affective contexts. Smiles were measured during a lab-based monologue task following either happy or sad emotion-evoking films. Psychological adjustment and social integration were measured longitudinally using data obtained in years prior to and after the experimental task. Duchenne (genuine) smiles predicted better long-term adjustment and this effect was mediated independently by both social integration and undoing of negative emotion during the monologue. These effects were observed only in the negative affective context. Non-Duchenne smiles were not related to psychological adjustment. Neither Duchenne nor non-Duchenne smiles during the monologue task were related to personality variables assessed in this study.     

LES CONDUITES SOCIALES CHEZ DES ENFANTS ‘AUDACIEUX’ DE 9–10 MOIS*

Among 38 infants of 9–10 months who were exposed to a strange person on the one hand, and to a novel inanimate object on the other hand, 17 left their mother and came near the stimulus in both situations. This study focuses on these 17 ‘bold’ infants, whose behaviors (place-shifts, looks, smiles, vocalizations, manipulations, contacts with mother) were compared from one situation to another (person/object), and also, within each situation, on their being emitted either near the stimulus or away from it (proximity/distance). Such comparisons showed that although these infants acted in almost the same way when they were close to the person or to the object, many aspects of their behavior nevertheless differed clearly from one situation to the other. With the object, the approach was immediate and the contact was a proximal one. With the person, on the other hand, the approach was delayed, and keeping a certain distance seemed essential to the establishment of the relation: it was mainly from afar that the infants communicated with the stranger, through behaviors that were well adapted to social interactions (looks and smiles). These results were interpreted as indicating that children of this age can truly understand the distinctive nature of social and nonsocial situations, and use the appropriate familiarization strategy required by these two types of situations.     

Perception of Genuine and Masking Smiles in Children and Adults: Sensitivity to Traces of Anger

The authors examined children's and adults' sensitivity to traces of anger in masking smiles by presenting participants with short video excerpts of smiles that differed by the intensity of an anger component. Fifty-two children, aged 6 to 12 years, and 26 adults were asked to judge whether a stimulus person was really happy or pretending to be happy. Six- and 7-year-old children were found to be sensitive to traces of anger, but less so than older children and adults. Researchers found evidence of explicit knowledge of the emotion hidden in masking smiles only in adult participants.     

Perception of genuine and masking smiles in children and adults: sensitivity to traces of anger

The authors examined children's and adults' sensitivity to traces of anger in masking smiles by presenting participants with short video excerpts of smiles that differed by the intensity of an anger component. Fifty-two children, aged 6 to 12 years, and 26 adults were asked to judge whether a stimulus person was really happy or pretending to be happy. Six- and 7-year-old children were found to be sensitive to traces of anger, but less so than older children and adults. Researchers found evidence of explicit knowledge of the emotion hidden in masking smiles only in adult participants.     

Effects of normal and perturbed social play on the duration and amplitude of different types of infant smiles

Different types of smiling varying in amplitude of lip corner retraction were investigated during 2 mother-infant games--peekaboo and tickle--at 6 and 12 months and during normally occurring and perturbed games. Using Facial Action Coding System (FACS), infant smiles were coded as simple (lip corner retraction only), Duchenne (simple plus cheek raising), play (simple plus jaw drop), and duplay (Duchenne plus jaw drop). In addition, again using FACS, the amplitude of lip corner retraction was coded on a 5-point scale. Rather than a single smile expression that differs only in amplitude, the authors found a complex family of different smile expressions differing in their duration and amplitude as a function of game, setup versus climax of the game, and perturbation. Both type of smiling and amplitude of smiling appear to be controlled independently by the infant in relation to the context. These findings reveal systematic and context-specific nuances in infant smiles in the 2nd half of the first year.     

Differences between traces of negative emotions in smile judgment

While a smile can reflect felt happiness, it can also be voluntarily produced, for instance, to mask negative emotions. Masking strategies are not always perfect and traces of the negative emotion can leak. The current study examined the role of traces of anger, sadness, fear and disgust in the judgment of authenticity of smiles. Participants judged the authenticity of the smiles while their eye movements were recorded. They were also asked if the stimuli comprised another emotion and, if so, what the emotion was. Results revealed that participants were sensitive to traces of negative emotions. Variations were observed between emotions with performance being best for traces of fear and lowest for traces of anger in the eyebrows in the judgment task. However, when the presence of a negative emotion was reported, participants were less accurate in identifying fear but more accurate in identifying anger. Furthermore, variations were observed as a function of the location of the trace whether in the mouth or eyes as a function of the emotion. Traces in the eyebrows were associated with better performance than traces in the mouth for sadness but the opposite was observed for anger. The performance at the judgment task was not linked to eye movement measures or explicit knowledge of the masked emotion. Future research should explore other explanation for the variations in performance in the judgments of authenticity of masking smiles such as emotional contagion.     

Pacifiers Disrupt Adults’ Responses to Infants’ Emotions

Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment examines whether pacifiers interfere with caretakers' ability to mimic infants' emotions. Adults saw photographs of infants with or without a pacifier. When infants had pacifiers, perceivers showed reduced EMG activity to infants' smiles. Smiles of infants using a pacifier were also rated as less happy than smiles depicted without a pacifier. The same pattern was observed for expressions of distress: adults rated infants presented with pacifiers as less sad than infants without pacifiers. We discuss deleterious effects of pacifier use for the perceiver's resonance with a child's emotions.