Positivity can cue familiarity

Given that familiarity is closely associated with positivity, the authors sought evidence for the idea that positivity would increase perceived familiarity. In Experiment 1, smiling and thus positively perceived novel faces were significantly more likely to be incorrectly judged as familiar than novel faces with neutral expressions. In Experiment 2, subliminal association with positive affect (a positively valenced prime) led to false recognition of novel words as familiar. In Experiment 3, validity judgments, known to be influenced by familiarity, were more likely to occur if participants were in happy mood states than neutral mood states. Despite their different paradigms and approaches, the results of these three studies converge on the idea that, at least under certain circumstances, the experience of positivity itself can signal familiarity, perhaps because the experience of familiarity is typically positive.     

Repetition priming and face processing: Priming occurs within the system that responds to the identity of a face

A familiar stimulus that has recently been recognized will be recognized a second time more quickly and more accurately than if it had not been primed by the earlier encounter. This is the phenomenon of “repetition priming”. Four experiments on repetition priming of face recognition suggest that repetition priming is a consequence of changes within the system that responds to the familiarity of a stimulus. In Experiment 1, classifying familiar faces by occupation facilitated subsequent responses to the same faces in a familiarity decision task (Is this face familiar or unfamiliar?) but not in an expression decision task (Is this face smiling or unsmiling?) or a sex decision task (Is this face male or female?). In Experiment 2, familiar faces showed repetition priming in a familiarity decision task, regardless of whether a familiarity judgment or an expression judgment had been required when the faces were first encountered. Expression decisions to familiar faces again failed to show repetition priming. In Experiment 3, familiar faces showed repetition priming in a familiarity decision task, regardless of whether a familiarity judgment or a sex judgment had been asked for when the faces were first encountered. Sex decisions to familiar faces again failed to show repetition priming. In Experiment 4, familiarity decisions continued to show repetition priming when a brief presentation time with encouragement to respond while the face was displayed reduced response latencies to speeds comparable to those for sex and expression judgments in Experiments 1 to 3. The results are problematic for theories that propose that repetition priming is mediated by episodic records of previous acts of stimulus encoding.     

Facial attractiveness biases the perception of eye contact

Attractive faces are appealing: We like to look at them, and we like to be looked at by them. We presented attractive and unattractive smiling and neutral faces containing identical eye regions with different gaze directions. Participants judged whether or not a face looked directly at them. Overall, attractive faces increased participants' tendency to perceive eye contact, consistent with a self-referential positivity bias. However, attractiveness effects were modulated by facial expression and gender: For female faces, observers more likely perceived eye contact in attractive than unattractive faces, independent of expression. For male faces, attractiveness effects were limited to neutral expressions and were absent in smiling faces. A signal detection analysis elucidated a systematic pattern in which (a) smiling faces, but not highly attractive faces, reduced sensitivity in gaze perception overall, and (b) attractiveness had a more consistent impact on bias than sensitivity measures. We conclude that combined influences of attractiveness, expression, and gender determine the formation of an overall impression when deciding which individual's interest in oneself may be beneficial and should be reciprocated.     

Facial attractiveness biases the perception of eye contact

Attractive faces are appealing: We like to look at them, and we like to be looked at by them. We presented attractive and unattractive smiling and neutral faces containing identical eye regions with different gaze directions. Participants judged whether or not a face looked directly at them. Overall, attractive faces increased participants' tendency to perceive eye contact, consistent with a self-referential positivity bias. However, attractiveness effects were modulated by facial expression and gender: For female faces, observers more likely perceived eye contact in attractive than unattractive faces, independent of expression. For male faces, attractiveness effects were limited to neutral expressions and were absent in smiling faces. A signal detection analysis elucidated a systematic pattern in which (a) smiling faces, but not highly attractive faces, reduced sensitivity in gaze perception overall, and (b) attractiveness had a more consistent impact on bias than sensitivity measures. We conclude that combined influences of attractiveness, expression, and gender determine the formation of an overall impression when deciding which individual's interest in oneself may be beneficial and should be reciprocated.     

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.     

Facilitative and interference effects of facial expressions on familiarity as a function of repetition priming frequency

Facial expressions of familiar faces have been found to influence identification. In this study, we hypothesize that faces with emotional expression are encoded for both structural and variant information resulting in more robust identification. Eighty-eight participants were presented faces with repetition priming frequencies of 2, 5, 10, and 20 (learning stage) and then judged the faces in terms of familiarity (testing stage). Participants were randomized into one of the following conditions: The facial expression between learning and testing stage remained the same (F-F), faces with facial expression shown in the learning stage were neutralized in the testing stage (F-N), or faces with neutral expressions shown in the learning stage had emotional expressions in the testing stage (N-F). Results confirmed our hypothesis and implications are discussed.     

Recognizing face identity from natural and morphed smiles

It is easier to identify a degraded familiar face when it is shown moving (smiling, talking; nonrigid motion), than when it is displayed as a static image (Knight & Johnston, 1997; Lander, Christie, & Bruce, 1999). Here we explore the theoretical underpinnings of the moving face recognition advantage. In Experiment 1 we show that the identification of personally familiar faces when shown naturally smiling is significantly better than when the person is shown artificially smiling (morphed motion), as a single static neutral image or as a single static smiling image. In Experiment 2 we demonstrate that speeding up the motion significantly impairs the recognition of identity from natural smiles, but has little effect on morphed smiles. We conclude that the recognition advantage for face motion does not reflect a general benefit for motion, but suggests that, for familiar faces, information about their characteristic motion is stored in memory.     

Recognizing face identity from natural and morphed smiles

It is easier to identify a degraded familiar face when it is shown moving (smiling, talking; nonrigid motion), than when it is displayed as a static image (Knight & Johnston, 1997; Lander, Christie, & Bruce, 1999). Here we explore the theoretical underpinnings of the moving face recognition advantage. In Experiment 1 we show that the identification of personally familiar faces when shown naturally smiling is significantly better than when the person is shown artificially smiling (morphed motion), as a single static neutral image or as a single static smiling image. In Experiment 2 we demonstrate that speeding up the motion significantly impairs the recognition of identity from natural smiles, but has little effect on morphed smiles. We conclude that the recognition advantage for face motion does not reflect a general benefit for motion, but suggests that, for familiar faces, information about their characteristic motion is stored in memory.     

A smile biases the recognition of eye expressions: Configural projection from a salient mouth

A smile is visually highly salient and grabs attention automatically. We investigated how extrafoveally seen smiles influence the viewers' perception of non-happy eyes in a face. A smiling mouth appeared in composite faces with incongruent non-happy (fearful, neutral, etc.) eyes, thus producing blended expressions, or it appeared in intact faces with genuine expressions. Attention to the eye region was spatially cued while foveal vision of the mouth was blocked by gaze-contingent masking. Participants judged whether the eyes were happy or not. Results indicated that the smile biased the evaluation of the eye expression: The same non-happy eyes were more likely to be judged as happy and categorized more slowly as not happy in a face with a smiling mouth than in a face with a non-smiling mouth or with no mouth. This bias occurred when the mouth and the eyes appeared simultaneously and aligned, but also to some extent when they were misaligned and when the mouth appeared after the eyes. We conclude that the highly salient smile projects to other facial regions, thus influencing the perception of the eye expression. Projection serves spatial and temporal integration of face parts and changes.     

A Smile is Just a Smile: But Only for Men. Sex Differences in Meaning of Faces Scales

This study tests psychometrics of the faces scale that is often used in organizational psychology to assess emotions, attitudes, and well-being. In analyzing 10,584 two-categorical judgments (“sad” versus “happy”) of 11 faces from 72 participants, women judged a face with a horizontal line as mouth (“neutral face”) more often sad than happy and significantly more often sad than men did. Moreover, women adapted their judgments to the range of faces under study in showing a significant contrast effect. In a range of neutral to bright smiling faces a face showing a mild smile was judged to be sad, while in a range of neutral to heavy griming faces a mild grim was judged to be happy. Sex differences in meaning of faces within faces scales and their implications for the use of the faces scale in work and organizational psychology are discussed.     

The effects of smiling on perceived age defy belief

It is a common belief that smiling makes people appear younger. Empirical findings, however, suggest that smiling faces are actually perceived as older than neutral faces. Here we show that these two apparently contradictory phenomena can co-exist in the same person. In the first experiment, participants were first asked to estimate the ages of a series of smiling or neutral faces. After that, they were asked to estimate the average age of the set of neutral and smiling faces they had just evaluated. Finally, they were asked what effect smiling has on one’s perceived age. In the experimental session, smiling faces were perceived as older than neutral faces. Nevertheless, after the experiment, consistent with their retrospective evaluations, participants recalled smiling faces as being younger than the neutral faces. Experiment 2 replicated and extended these results to a set of emotional expressions that also included surprised faces. Smiling faces were again perceived as older than neutral faces, which were in turn perceived as older than surprised faces. Again, retrospective evaluations were consistent with the belief that smiling makes people look younger. The findings show that this belief, well-rooted in popular media, is a complete misconception.     

Familiar eyes are smiling: on the role of familiarity in the perception of facial affect

Quickly and accurately perceiving others' facial affect is paramount for successful social interaction. This work investigates the role of familiarity in helping us to interpret others' facial emotions. In Experiments 1 and 2, participants viewed several faces, some familiar and some novel, and judged how happy each face appeared. As predicted, results showed that familiar faces were perceived as happier than were novel faces. In Experiment 3, participants again viewed several faces, some familiar and some not, and rated the perceived anger or happiness of these faces. As expected, familiar faces were perceived as happier and less angry than were novel faces. Thus, these results suggest that familiarity is one cue we use to interpret the facial affect of others. Copyright © 2007 John Wiley & Sons, Ltd.     

Smiling emphasizes perceived distinctiveness of faces

In this study, 114 Japanese observers (56 men and 58 women) rated the distinctiveness of 48 neutral faces and 48 smiling faces. Analysis showed smiling faces were rated as significantly more distinctive than neutral ones. Greater perceived distinctiveness provides an explanation for previous results that smiling faces are better remembered than faces with neutral expressions.     

The contribution of facial regions to judgements of happiness and trustworthiness from dynamic expressions

What expressive facial features and processing mechanisms make a person look trustworthy, relative to happy? Participants judged the un/happiness or un/trustworthiness of people with dynamic expressions in which the eyes and/or the mouth unfolded from neutral to happy or vice versa. Faces with an unfolding smile looked more trustworthy and happier than faces with a neutral mouth, regardless of the eye expression. Unfolding happy eyes increased both trustworthiness and happiness only in the presence of a congruent unfolding smiling mouth. Nevertheless, the contribution of the mouth was greater for happiness than for trustworthiness; and the mouth was especially visually salient for expressions favouring happiness more than trustworthiness. We conclude that the categorisation of facial happiness is more automatically driven by the visual saliency of a single feature, that is, the smiling mouth, while perception of trustworthiness is more strategic, with the eyes being necessarily incorporated into a configural face representation.     

Influences of familiarity on the processing of faces

Three experiments are reported in which undergraduate subjects made simple perceptual judgements about the faces of familiar and unfamiliar academic staff. Any effects of familiarity in these tasks were assessed by comparison with performance on the two groups of faces when both sets were unfamiliar to student subjects at a different university. In experiment 1 there was no effect of familiarity of the faces on a task requiring judgements of expression, consistent with recent models of face processing in which expression analysis proceeds independently from the analysis of identity. In experiment 2 there was a significant effect of familiarity on a task in which the sex of the faces was judged. This appeared to be due to familiarity acting to facilitate only those faces whose sex was difficult to judge from the picture presented. In experiment 3, significant effects of familiarity were also observed when the task was to distinguish intact faces from jumbled faces. Although the effects of familiarity in experiments 2 and 3 were small and emerged in interactions between item sets and university, they suggest that a simple perceptual hierarchy of the kind proposed by Ellis requires some revision.     

The warm glow heuristic: when liking leads to familiarity

Five studies demonstrate that the positive valence of a stimulus increases its perceived familiarity, even in the absence of prior exposure. For example, beautiful faces feel familiar. Two explanations for this effect stand out: (a). Stimulus prototypicality leads both to positivity and familiarity, and (b). positive affect is used to infer familiarity in a heuristic fashion. Studies 1 and 2 show that attractive faces feel more familiar than average ones and that prototypicality accounts for only part of this effect. In Study 3, the rated attractiveness of average faces was manipulated by contrast, and their perceived familiarity changed accordingly, although their inherent prototypicaliry remained the same. In Study 4, positive words felt more familiar to participants than neutral and negative words. Study 5 shows that the effect is strongest when recognition is difficult. The author concludes that both prototypicality and a warm glow heuristic are responsible for the "good-is-familiar" phenomenon.     

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.     

Effects of familiarity on the perceptual integrality of the identity and expression of faces: the parallel-route hypothesis revisited

The effects of familiarity on selective attention for the identity and expression of faces were tested using Garner's speeded-classification task. In 2 experiments, participants classified expression (or identity) of familiar and unfamiliar faces while the irrelevant dimension of identity (or expression) was either held constant (baseline condition) or varied randomly (filtering condition). Selective attention was measured by the difference in performance between these 2 conditions. Failure of selective attention was larger for familiar than for unfamiliar faces. In addition, failure of selective attention was found both for identity and for expression judgments. These findings show that familiarity increases (he perceptual integrality between identity and expression, and they question previous studies arguing that identity judgments are always resistant to irrelevant variations in expression. The authors suggest that the systems processing identity and expression are interconnected in that facial identity serves as a reference from which expressions can be more easily derived.     

Predictive gaze cues affect face evaluations: The effect of facial emotion

When we see someone change their direction of gaze, we spontaneously follow their eyes because we expect people to look at interesting objects. Bayliss and Tipper (2006) examined the consequences of observing this expectancy being either confirmed or violated by faces producing reliable or unreliable gaze cues. Participants viewed different faces that would consistently look at the target, or consistently look away from the target: The faces that consistently looked towards targets were subsequently chosen as being more trustworthy than the faces that consistently looked away from targets. The current work demonstrates that these gaze contingency effects are only detected when faces create a positive social context by smiling, but not in the negative context when all the faces held angry or neutral expressions. These data suggest that implicit processing of the reward contingencies associated with gaze cues relies on a positive emotional expression to maintain expectations of a favourable outcome of joint attention episodes.