The effect of facial feedback on the evaluation of statements describing everyday situations and the role of awareness

According to theories of embodiment enacting a smile or a frown can positively or negatively influence one’s evaluations, even without awareness of one’s facial activity. While some previous studies found evidence for facial feedback effects, recent replication attempts could not confirm these findings. Are our decisions throughout the day amenable to the state of our facial muscles? We tested the effect of smiling and frowning on the evaluation of emotional sentences describing everyday situations. While most previous studies based their assessment of awareness on verbal debriefing interviews without explicitly defined criteria, we employed a written debriefing questionnaire in order to avoid potential bias when identifying participants’ awareness. Our results indicate that smiling/frowning increased/decreased sentence ratings only for participants aware of their expressions. This emphasizes the importance of more rigorous awareness tests in facial feedback studies. Our results support the view that facial feedback cannot necessarily influence us without conscious mediation.     

When smiles (and frowns) speak words: Does power impact the correspondence between self-reported affect and facial expressions?

Self-reported experiences are often poor indicators of outward expressions. Here we examine social power as a variable that may impact the relationship between self-reported affect and facial expressions. Earlier studies addressing this issue were limited by focusing on a single facial expression (smiling) and by using different, less sensitive methods that yielded mostly null results. Sampling, for the first time, self-reported affect repeatedly in response to different negative, neutral and positive stimuli, and measuring concurrent facial muscle activation via electromyography, we found that high power (vs. baseline) increased the correspondence between self-reported positive affect and smiling. There was also an indication that high power (vs. baseline) bolstered the association between self-reported negative affect and frowning but the effect did not pass more stringent criteria for significance (p ≤ .005) and was therefore deemed inconclusive. The prediction that low power (vs. baseline) decreases the correspondence between self-reported affect and smiling and frowning facial expressions was not supported. Taken together, it would appear that (high) power can impact the relationship between self-reported affect and facial expressions, but it remains to be seen whether this effect extends beyond smiling facial expressions.     

Attention to Emotion and Non-Western Faces: Revisiting the Facial Feedback Hypothesis

In a modified replication of Strack, Martin, and Stepper's demonstration of the Facial Feedback Hypothesis (1988), we investigated the effect of attention to emotion on the facial feedback process in a non-western cultural setting. Participants, recruited from two universities in Ghana, West Africa, gave self-reports of their perceived levels of attention to emotion, and then completed cartoon-rating tasks while randomly assigned to smiling, frowning, or neutral conditions. While participants with low Attention to Emotion scores displayed the usual facial feedback effect (rating cartoons as funnier when in the smiling compared to the frowning condition), the effect was not present in individuals with high Attention to Emotion. The findings indicate that (1) the facial feedback process can occur in contexts beyond those in which the phenomenon has previously been studied, and (2) aspects of emotion regulation, such as Attention to Emotion can interfere with the facial feedback process.     

Brighten up: Smiles facilitate perceptual judgment of facial lightness

The metaphoric expression ‘bright smile’ may reflect the actual judgment of facial lightness under varying emotional expressions. The present research examined whether people in fact judge smiling faces as perceptually brighter than frowning faces. Four studies demonstrated that participants believed smiling faces were brighter compared to frowning faces in a binary choice task and in an absolute judgment task. The results suggest that emotional expressions (i.e., smiles and frowns) can bias judgments of facial brightness in ways consistent with the metaphor. Among other implications, such results suggest that stereotypes about darker-skinned individuals may be attenuated by smiles.     

Error monitoring in the hemispheres: the effect of lateralized feedback on lexical decision.

Does each hemisphere have its own system for monitoring and responding to errors? Three experiments investigate the effect of presenting lateralized accuracy feedback in a bilateral lexical decision task. We presented feedback after each trial in either the left visual field (LVF) or right visual field (RVF). In Experiment 1 the feedback stimuli were faces smiling or frowning, in Experiment 2 we used colored squares, and Experiment 3 tested the effect of verbal feedback. Negative feedback presented in the LVF tended to improve performance on the following trial, while the same negative feedback in the RVF tended to disrupt performance on the following trial. This result was strongest with the faces as feedback, was less pronounced with colored squares, and disappeared with verbal feedback. The results are interpreted as suggesting a right hemisphere superiority for error monitoring that depends on the mode of feedback.     

Recognition,discrimination and categorization of smiling by 5-month-old infants

Perceiving emotions correctly is foundational to the development of interpersonal skills. Five-month-old infants’ abilities to recognize, discriminate and categorize facial expressions of smiling were tested in three coordinated experiments. Infants were habituated to four degrees of smiling modeled by the same or different people; following habituation, infants were presented with a new degree of smile worn by the same and by a new person (Experiment 1), a new degree of smile and a fearful expression worn by the same person (Experiment 2) or a new degree of smile and a fearful expression worn by new people (Experiment 3). Infants showed significant novelty preferences for the new person smiling and for the fearful expressions over the new degree of smiling. These findings indicate that infants at 5 months can categorize the facial expression of smiling in static faces, and yet recognize the same person despite changes in facial expression; this is the youngest age at which these abilities have been demonstrated. The findings are discussed in light of the significance of emotion expression face processing in social interaction and infants’ categorization of faces.     

Automatic behavioural responses to valence: Evidence that facial action is facilitated by evaluative processing

Are motor schemata of facial action spontaneously activated upon the processing of evaluative information? In this case, the processing of positive evaluative information should immediately trigger the motor schema of smiling, and the processing of negative information should trigger frowning. This hypothesis was tested in two experiments in which participants were required to respond to positive and negative words by either smiling or frowning. Electromyogram (EMG) activity was recorded over the brow muscle region (corrugator supercilii) and over the cheek muscle region (zygomaticus major) in order to quantify the latency of muscular response as a dependent measure. In Experiment 1 we found that participants were faster at contracting their zygomaticus muscle (which is involved in smiling) when evaluating positive words, and faster at contracting their corrugator muscle (which is involved in frowning) when evaluating negative words. In Experiment 2, participants were required to respond with the contraction of one of the two muscles whenever a word appeared on the computer screen. Again, we found that responses were faster to congruent response valence combinations than to incongruent response valence combinations. These findings support the hypothesis that evaluative processing is directly linked to motor schemata of facial muscles.     

Dogs can discriminate human smiling faces from blank expressions

Dogs have a unique ability to understand visual cues from humans. We investigated whether dogs can discriminate between human facial expressions. Photographs of human faces were used to test nine pet dogs in two-choice discrimination tasks. The training phases involved each dog learning to discriminate between a set of photographs of their owner’s smiling and blank face. Of the nine dogs, five fulfilled these criteria and were selected for test sessions. In the test phase, 10 sets of photographs of the owner’s smiling and blank face, which had previously not been seen by the dog, were presented. The dogs selected the owner’s smiling face significantly more often than expected by chance. In subsequent tests, 10 sets of smiling and blank face photographs of 20 persons unfamiliar to the dogs were presented (10 males and 10 females). There was no statistical difference between the accuracy in the case of the owners and that in the case of unfamiliar persons with the same gender as the owner. However, the accuracy was significantly lower in the case of unfamiliar persons of the opposite gender to that of the owner, than with the owners themselves. These results suggest that dogs can learn to discriminate human smiling faces from blank faces by looking at photographs. Although it remains unclear whether dogs have human-like systems for visual processing of human facial expressions, the ability to learn to discriminate human facial expressions may have helped dogs adapt to human society.     

When the smile is a cue to familiarity

The question discussed in the two following experiments concerns the effect of facial expressions on face recognition. Famous and unknown faces with neutral or smiling expression were presented for different inspection durations (15 ms vs 1000 ms). Subjects had to categorise these faces as famous or unknown (Experiment 1), or estimate their degree of familiarity on a rating scale (Experiment 2). Results showed that the smile increased ratings of familiarity for unfamiliar faces (Experiments 1 and 2) and for famous faces (Experiment 2). These data are discussed in the framework of current face-recognition models and are interpreted in terms of social value of the smile. It is proposed that the smiling bias found here acts at the level of the decision process.     

When the smile is a cue to familiarity

The question discussed in the two following experiments concerns the effect of facial expressions on face recognition. Famous and unknown faces with neutral or smiling expression were presented for different inspection durations (15 ms vs 1000 ms). Subjects had to categorize these faces as famous or unknown (Experiment 1), or estimate their degree of familiarity on a rating scale (Experiment 2). Results showed that the smile increased ratings of familiarity for unfamiliar faces (Experiments 1 and 2) and for famous faces (Experiment 2). These data are discussed in the framework of current face-recognition models and are interpreted in terms of social value of the smile. It is proposed that the smiling bias found here acts at the level of the decision process.     

The value of genuine and polite smiles

Humans show remarkable ability to adapt their social behavior to suit the changing requirements of their interactions. An interaction partner's social cues, particularly facial expressions, likely play an important role in motivating and reinforcing this behavioral adaptation. Over three studies, we test a key aspect of this idea. Specifically, we ask how the reinforcement value of facial expressions compares to that of nonsocial feedback and to what degree two frequently occurring expressions (genuine and polite smiles) differ in reinforcement value. Our findings show that social feedback is preferred over nonsocial feedback and that genuine smiles are preferred over polite smiles. Based on a logistic model of our data, we show that both monetary and social values of stimuli contribute significantly to participants' decisions. Indeed, participants were willing to sacrifice the chance of a monetary reward to receive a genuine smile and produced inflated estimates of the value of genuinely smiling faces. These findings suggest that genuine smiles, and potentially other social cues, may be useful social reinforcers and therefore important in the control of social behavior on a moment-to-moment basis during interaction.     

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.     

Toddlers’ affective responses to sociomoral scenes: Insights from physiological measures

A growing literature suggests that preverbal infants are sensitive to sociomoral scenes and prefer prosocial agents over antisocial agents. It remains unclear, however, whether and how emotional processes are implicated in infants’ responses to prosocial/antisocial actions. Although a recent study found that infants and toddlers showed more positive facial expressions after viewing helping (vs. hindering) events, these findings were based on naïve coder ratings of facial activity; furthermore, effect sizes were small. The current studies examined 18- and 24-month-old toddlers’ real-time reactivity to helping and hindering interactions using three physiological measures of emotion-related processes. At 18 months, activity in facial musculature involved in smiling/frowning was explored via facial electromyography (EMG). At 24 months, stress (sweat) was explored via electrodermal activity (EDA). At both ages, arousal was explored via pupillometry. Behaviorally, infants showed no preferences for the helper over the hinderer across age groups. EMG analyses revealed that 18-month-olds showed higher corrugator activity (more frowning) during hindering (vs. helping) actions, followed by lower corrugator activity (less frowning) after hindering (vs. helping) actions finished. These findings suggest that antisocial actions elicited negativity, perhaps followed by brief disengagement. EDA analyses revealed no significant event-related differences. Pupillometry analyses revealed that both 18- and 24-month-olds’ pupils were smaller after viewing hindering (vs. helping), replicating recent evidence with 5-month-olds and suggesting that toddlers also show less arousal following hindering than following helping. Together, these results provide new evidence with respect to whether and how arousal/affective processes are involved when infants process sociomoral scenarios.     

Smiling, frowning, and autonomic activity in mildly depressed and nondepressed men in response to emotional imagery of social contexts

The study examined self-reported emotion and facial muscle and autonomic activity of depressed and nondepressed men in response to the social context of emotional situations. 20 university men, assessed on the Beck Depression Inventory, were asked to imagine happy and sad situations with and without visualizing other people. No differences were found between men classified as depressed and nondepressed on self-reported emotion and facial muscle activity. Smiling did not show differences between social contexts although self-reported happiness was increased during happy-social compared to happy-solitary imagery. Adjusting smiling for social context differences in happiness showed less smiling during happy-social than during happy-solitary imagery. In contrast, self-reported sadness and frowning were greater during sad-social compared to sad-solitary imagery. No differences between social contexts were found when frowning was adjusted for social context differences in sadness. Depressed-scoring men showed higher mean heart rate during sad-social than sad-solitary imagery whereas nondepressed-scoring men showed higher mean heart rate during happy social compared to happy-solitary imagery. The results indicate that men may frown more when sad but generally do not smile more during happy-social imagery, independent of depression. Depressed mood may affect heart rate during sad imagery but may not alter facial muscle activity and self:reported emotion in men.     

Perception and Expressing Habits of Smiling and Angry Expressions Modulated by Facial Physical Attractiveness in Asian Female Persons

In this study, we investigated the effects of facial physical attractiveness on perception and expressing habit of smiling and angry expressions. In experiment 1, 20 participants rated 60 photo subjects’ smiling and angry expressions of uncontrolled physical expression configuration. The results showed that for the angry faces, the perceived expression intensity and the expression naturalness in the attractive group were significantly stronger than those in the unattractive group; for the smiling faces, this attractiveness bias was not observed. In experiment 2, using artificial expressions made by an identical expression template, interestingly, the perceived expression intensity and the expression naturalness of the smiling faces in the attractive group were stronger than those in the unattractive group, while the impression strength of anger between the two groups was approximately the same. A comparison of the two observations suggests that facial physical attractiveness can enhance the perceived intensity of a smiling expression but not an angry expression, and that the inconsistencies between the two experiments are due to the difference of expressing habits between unattractive and attractive persons. These results have implications as regards the effect of facial attractiveness on the expressing habits of expression senders and the person’s development of social skills.     

Facial expressions of singers influence perceived pitch relations

In four experiments, we examined whether facial expressions used while singing carry musical information that can be “read” by viewers. In Experiment 1, participants saw silent video recordings of sung melodic intervals and judged the size of the interval they imagined the performers to be singing. Participants discriminated interval sizes on the basis of facial expression and discriminated large from small intervals when only head movements were visible. Experiments 2 and 3 confirmed that facial expressions influenced judgments even when the auditory signal was available. When matched with the facial expressions used to perform a large interval, audio recordings of sung intervals were judged as being larger than when matched with the facial expressions used to perform a small interval. The effect was not diminished when a secondary task was introduced, suggesting that audio-visual integration is not dependent on attention. Experiment 4 confirmed that the secondary task reduced participants’ ability to make judgments that require conscious attention. The results provide the first evidence that facial expressions influence perceived pitch relations.     

Integrating gaze direction and expression in preferences for attractive faces

Few studies have investigated how physical and social facial cues are integrated in the formation of face preferences. Here we show that expression differentially qualifies the strength of attractiveness preferences for faces with direct and averted gaze. For judgments of faces with direct gaze, attractiveness preferences were stronger for smiling faces than for faces with neutral expressions. By contrast, for judgments of faces with averted gaze, attractiveness preferences were stronger for faces with neutral expressions than for smiling faces. Because expressions can differ in meaning depending on whether they are directed toward or away from oneself, it is only by integrating gaze direction, facial expression, and physical attractiveness that one can unambiguously identify the most attractive individuals who are likely to reciprocate one's own social interest.     

You may look unhappy unless you smile: The distinctiveness of a smiling face against faces without an explicit smile

An expressionless face is often perceived as rude whereas a smiling face is considered as hospitable. Repetitive exposure to such perceptions may have developed stereotype of categorizing an expressionless face as expressing negative emotion. To test this idea, we displayed a search array where the target was an expressionless face and the distractors were either smiling or frowning faces. We manipulated set size. Search reaction times were delayed with frowning distractors. Delays became more evident as the set size increased. We also devised a short-term comparison task where participants compared two sequential sets of expressionless, smiling, and frowning faces. Detection of an expression change across the sets was highly inaccurate when the change was made between frowning and expressionless face. These results indicate that subjects were confused with expressed emotions on frowning and expressionless faces, suggesting that it is difficult to distinguish expressionless face from frowning faces.     

Social context effects on facial activity in a negative emotional setting

Evidence for A. J. Fridlund's (e.g.. 1994) "behavioral ecology view" of human facial expression comes primarily from studies of smiling in response to positive emotional stimuli. Smiling may be a special case because it clearly can, and often does serve merely communicative functions. The present experiment was designated (a) to assess the generalizability of social context effects to facial expressions in response to negative emotional stimuli and (b) to examine whether these effects are mediated by social motives, as suggested by the behavioral ecology view. Pairs of friends or strangers viewed film clips that elicited different degrees of sad affect, in either the same or a different room; a control group participated alone. Dependent variables included facial activity, subjective emotion, and social motives. Displays of sadness were influenced by stimulus intensity and were lower in all social conditions than in the alone condition. Unexpectedly, social context effects were also found for smiling.     

The implicit cognition of reciprocal exchange: automatic retrieval of positive and negative experiences with partners in a prisoner's dilemma game

Models of reciprocity imply that cheater detection is an important prerequisite for successful social exchange. Considering the fundamental role of memory in reciprocal exchange, these theories lead to the prediction that memory for cheaters should be preferentially enhanced. Here, we examine whether information of a partner's previous behaviour in an interaction is automatically retrieved when encountering the face of a partner who previously cheated or cooperated. In two studies, participants played a sequential prisoner's dilemma game with cheaters and cooperative partners. Alternating with the game blocks, participants were asked to classify the smiling or angry facial expressions of cooperators and cheaters. Both experiments revealed congruence effects, reflecting faster identification of the smiles of cooperators (Experiments 1 and 2) and faster identification of the angry facial expressions of cheaters (Experiment 2). Our study provides evidence for the automatic retrieval of the partner's behaviour in the game, regardless of whether partners cheated or cooperated, and thus provides further evidence against the cheater detection hypothesis.