When he smiles: Attractiveness preferences for male faces expressing emotions.

The impact of sexual dimorphism on facial attractiveness has been controversial owing to contradictory results, particularly in studies on female preferences. Given that sexually dimorphic facial features, especially more masculine ones, have been previously related to the perception of anger, we investigated the bi-directional influence of emotional expressions and facial masculinity and explored their impact on women's preferences for facial masculinity. We confirmed the effect of facial sexual dimorphism on the perception of emotional cues (happiness and anger) and explored whether smiling or angry expressions influence women's perception of masculinity in male faces. Additionally, we examined women's preferences for emotionally expressive male faces altered along a continuum of masculinity. The results showed that masculinised faces are perceived as angrier, while feminised faces are perceived as happier (Experiment 1), and that angry faces are perceived as more masculine when compared with happy faces (Experiment 2). It is noteworthy that our Experiment 3 uncovered a pivotal finding: women prefer reduced feminisation in happy faces compared with neutral/angry faces. This suggests that the avoidance response observed towards masculinity is attenuated by a smiling expression. The current study introduces a new perspective to be considered when exploring the role of facial masculinity in women's attractiveness preferences.

Protein detection by fluorescence of manually cleaned high-speed dental handpieces.

We analyzed the effectiveness of manual cleaning protocols performed on high-speed dental handpieces, using protein identification by fluorescence. Although one protocol was able to able to lower the amount of protein, >40% of the handpieces showed amounts of residual protein at unacceptable levels.

How head posture affects perceived cooperativeness: A cross-cultural perspective.

Previous research has tested whether culture moderates the relationship between head tilt and perceptions of a cooperation-relevant construct. In this paper, we replicated the effects of head posture on perceived traits and compared Chinese and American participants to explore whether difference in cultural background (collectivist and individualist) affects perceptual attribution. Specifically, we investigated how head posture (level, up or down) affects perceptions of cooperativeness. In Experiment 1, Chinese and American participants rated Asian and Caucasian faces in three postures for perceived cooperativeness on a seven-point Likert scale. In Experiment 2, participants ranked the cooperativeness of the three postures of the same faces. In Experiment 3, participants scrolled through face images and manually manipulated vertical head angle to maximise apparent cooperativeness. We found that for both Chinese and American participants a neutral head level posture was perceived as more cooperative than head up and down postures. The optimal head posture for maximised apparent cooperativeness was close to level but with a slight downward rotation. While there was cross-cultural consistency in perceptions, Chinese participants exhibited greater sensitivity to postural cues in their judgments of cooperation compared to American participants. Our results suggest a profound effect of posture on the perception of cooperativeness that is common across cultures and that there are additional subtle cross-cultural differences in the cues to cooperativeness.

Representations of facial expressions since Darwin.

Darwin's book on expressions of emotion was one of the first publications to include photographs (Darwin, The expression of the emotions in Man and animals, 1872). The inclusion of expression photographs meant that readers could form their own opinions and could, like Darwin, survey others for their interpretations. As such, the images provided an evidence base and an 'open source'. Since Darwin, increases in the representativeness and realism of emotional expressions have come from the use of composite images, colour, multiple views and dynamic displays. Research on understanding emotional expressions has been aided by the use of computer graphics to interpolate parametrically between different expressions and to extrapolate exaggerations. This review tracks the developments in how emotions are illustrated and studied and considers where to go next.

Clothing Aesthetics: Consistent Colour Choices to Match Fair and Tanned Skin Tones.

Fashion stylists advise clothing colours according to personal categories that depend on skin, hair and eye colour. These categories are not defined scientifically, and advised colours are inconsistent. Such caveats may explain the lack of formal tests of clothing colour aesthetics. We assessed whether observers preferred clothing colours that are linked to variation in melanin levels among White women. For this, we presented 12 women's faces: six with fair skin (relatively lower in melanin) and six with tanned skin (relatively higher in melanin). Across two experiments, observers (N = 96 and 75) selected the colour (hue and saturation or hue and value) of simulated clothing that most suited the skin tone of each face. Observers showed strong preferences for red and blue hues, and in addition favoured 'cool' blue hues to match fair skin and 'warm' orange/red hues to match tanned skin. This finding suggests that skin tone can determine colour preferences for clothes.

Misperceptions of opposite-sex preferences for thinness and muscularity.

Thin and muscular have been characterized as ideals for women and men, respectively. Little research has investigated whether men and women have accurate perceptions of opposite-sex preferences of thinness and muscularity. Further, no study has explored whether opposite-sex perceptions of thinness and muscularity preferences differ for short-term and long-term relationships. The present study set out to address these questions. We used interactive 3D human models to represent bodies varying in size (body mass index/BMI weight scaled by height) and body composition. University-aged (18-31) White European heterosexual men and women were asked to choose their own and ideal body shape, the ideal body shape for a short- and a long-term partner, and the body shape they thought the opposite-sex would most like for short- and long-term partners. Women overestimated the thinness that men prefer in a partner and men overestimated the heaviness and muscularity that women prefer in a partner. These misperceptions were more exaggerated for short-term relationships than for long-term relationships. The results illustrate the importance of investigating misperceptions of opposite-sex preferences and raise the possibility that correcting misperceptions might have utility in reducing body dissatisfaction or eating disorders.

Reactions to an Online Demonstration of the Effect of Increased Fruit and Vegetable Consumption on Appearance: Survey Study.

BACKGROUND: Inadequate fruit and vegetable consumption causes a considerable disease burden and premature mortality. Despite public health promotion of a healthy diet, the average consumption is still below recommended levels. Fruit and vegetable consumption influences human skin color, increasing red/yellow/orange pigment in the skin. Given that this color is deemed attractive and healthy-looking, the appearance benefit may motivate to eat more fruit and vegetables. Such appearance motivation could be particularly useful in young individuals who currently eat the least fruit and vegetables. OBJECTIVE: Our objectives were to assess how widely the impact of diet on skin color is known within the UK and to compare the strength of motivation to eat fruit and vegetables based on health and appearance benefits among different demographic groups. METHODS: Four groups of UK residents (N=200 per group) were recruited through the Prolific online platform. Groups comprised younger (aged 18-24) and older adults (aged 40-60) of low and high self-reported socioeconomic status (1-5 and 6-10 on a 10-point rating scale). Facial images simulating the skin color associated with low and high fruit and vegetable diets were shown to participants. Questionnaires were used to assess (1) background knowledge of the health and skin color effects of dietary fruit and vegetables, (2) the specific motivational impact of the skin color illustration, and (3) the relative importance of motivation to consume fruit and vegetables arising from health and skin color appearance benefits. RESULTS: We found that 61% (n=487) of all participants were unaware of the dietary-skin color association. We also found that 57% (n=457) of participants found the simple demonstration of the dietary impact on skin color positively motivating to eat more fruit and vegetables. The visual demonstration was equally motivating for participants of high and low self-reported socioeconomic status (P=.63) and different ethnic backgrounds (White N=453, Black N=182, Asian N=87, P=.22). Health benefits from a diet high in fruit and vegetables were regarded as more motivating than skin color appearance benefits. The appearance-changing benefits of a high fruit and vegetable diet (compared to the health benefits) were relatively more important for the younger participants (Mann-Whitney U=96,263, P<.001) and for women (N=489) than for men (N=310, U=83,763, P=.01). CONCLUSIONS: These findings indicate that the promotion of the skin color effects of diets high in fruit and vegetables could provide additional motivation for a healthier diet. Our study indicates the broad appeal of appearance benefits from dietary fruit and vegetable (across ethnicity and socioeconomic status) and particularly amongst young adults where an inadequate diet is most prevalent.

Skin Color Cues to Human Health: Carotenoids, Aerobic Fitness, and Body Fat.

Colorful carotenoid ornaments are sexually selected signals of health in many species. In humans too, carotenoids could provide a perceptible cue to health as they impart an attractive yellow-orange color to skin. Increasing carotenoid pigmentation and skin yellowness is associated with increased fruit and vegetable intake, but whether other aspects of human health benefit skin color is unknown. Carotenoids, as antioxidants, help maintain oxidative balance but are expended in this role. Therefore, any health factor affecting oxidative balance could alter the quantity of carotenoids available to color skin. Exercise increases endogenous antioxidant capacity and consequently may decrease expenditure of carotenoids. Fitness could also raise skin carotenoids by lowering body fat (a source of oxidative stress). Here we investigate the relationship between skin color (measured spectrophotometrically), aerobic fitness (measured by estimating the maximum volume of oxygen that a person can use per unit of time, VO2 max), and body fat. In a cross-sectional design, we find that both higher aerobic fitness and lower body fat are predictors of skin yellowness, independent of each other and dietary fruit and vegetable intake. In a longitudinal design over 8 weeks, we found that increase in fitness and decrease in body fat were independently associated with an increase in skin yellowness. Change in self-reported stress and sleep were further predictors of skin yellowness indicating a more general relation between health and skin tone. Simulations of the skin color associated with higher fitness were found to appear healthier. Hence, our results suggest that increasing cardiovascular fitness and decreasing fat levels produce a healthier skin color. Such findings have repercussions for public health because improved attractiveness can provide an incentive for a healthier lifestyle, including exercise and weight regulation.

The Value of Averageness in Aesthetic Rhinoplasty: Humans Like Average Noses.

BACKGROUND: The aesthetic ideal of the nose eludes clear definition. Averageness may be an important determinant of ideal nasal shape: research has shown that averageness plays an important role in the human perception of facial attractiveness. OBJECTIVES: The aim of this study was to test whether an averaged nasal shape is attractive, and whether deviation away from average is associated with decreased attractiveness. METHODS: Photographic series of the face were obtained from 80 Caucasian female volunteers aged 25-40 years. A mathematically averaged composite image was created from the first 40 volunteers. Forty-one panel members were recruited to judge the attractiveness of the nose of each original image and the composite, based on a 5-point Likert scale ranging from 1 (very ugly) to 5 (very pretty). Deviation of nasal shape from average was calculated by principal components analysis of standardized nasal landmarks. RESULTS: Twenty-one respondents were male (51%). The mean age of the respondents was 35.3 [15.6] years. The rating of the composite was significantly higher than the distribution of ratings for the 80 original nose images (4.2 vs 2.8, t = 31.24, P < 0.001). The rating of the original nose images correlated negatively with deviation from average shape (r = -0.40, n = 80, P < 0.001). CONCLUSIONS: In Caucasian females, a mathematically averaged nose is an attractive nose. Furthermore, the more an individual nose shape resembles the average shape, the more attractive it is rated. Calculating deviation from average before and after rhinoplasty may aid in objectively measuring aesthetic rhinoplasty outcome.

Pathogen disgust sensitivity changes according to the perceived harshness of the environment.

Much research has explored behaviours that are linked with disgust sensitivity. Few studies, however, have been devoted to understanding how fixed or variable disgust sensitivity is. We therefore aimed to examine whether disgust sensitivity can change with the environment by repeatedly testing students whose environment was not changing as well as student cadets undergoing intensive training at an army camp. We found that an increase in the perceived harshness of the environment was associated with a decrease in pathogen disgust sensitivity. Our results support the idea that disgust sensitivity is malleable depending on the environment. More specifically, we propose that in a harsh environment, where survival may be more difficult, pathogen disgust sensitivity may decrease to allow the consumption of available resources.

A Web-Based Photo-Alteration Intervention to Promote Sleep: Randomized Controlled Trial.

BACKGROUND: Receiving insufficient sleep has wide-ranging consequences for health and well-being. Although educational programs have been developed to promote sleep, these have had limited success in extending sleep duration. To address this gap, we developed a Web-based program emphasizing how physical appearances change with varying amounts of sleep. OBJECTIVE: The aims of this study were to evaluate (1) whether participants can detect changes in appearances as a function of sleep and (2) whether this intervention can alter habitual sleep patterns. METHODS: We conducted a 5-week, parallel-group, randomized controlled trial among 70 habitual short sleepers (healthy adults who reported having <7 hours of sleep routinely). Upon study enrollment, participants were randomly assigned (1:1) to receive either standard information or an appearance-based intervention. Both groups received educational materials about sleep, but those in the appearance group also viewed a website containing digitally edited photographs that showed how they would look with varying amounts of sleep. As the outcome variables, sleep duration was monitored objectively via actigraphy (at baseline and at postintervention weeks 1 and 4), and participants completed a measure of sleep hygiene (at baseline and at postintervention weeks 2, 4, and 5). For each outcome, we ran intention-to-treat analyses using linear mixed-effects models. RESULTS: In total, 35 participants were assigned to each group. Validating the intervention, participants in the appearance group (1) were able to identify what they looked like at baseline and (2) judged that they would look more attractive with a longer sleep duration (t26=10.35, P<.001). In turn, this translated to changes in sleep hygiene. Whereas participants in the appearance group showed improvements following the intervention (F1,107.99=9.05, P=.003), those in the information group did not (F1,84.7=0.19, P=.66). Finally, there was no significant effect of group nor interaction of group and time on actigraphy-measured sleep duration (smallest P=.26). CONCLUSIONS: Our findings suggest that an appearance-based intervention, while not sufficient as a stand-alone, could have an adjunctive role in sleep promotion. TRIAL REGISTRATION: ClinicalTrials.gov NCT02491138; https://clinicaltrials.gov/ct2/show/study/NCT02491138.

Fear of Violence among Colombian Women Is Associated with Reduced Preferences for High-BMI Men.

Recent studies reveal that violence significantly contributes to explaining individual's facial preferences. Women who feel at higher risk of violence prefer less-masculine male faces. Given the importance of violence, we explore its influence on people's preferences for a different physical trait. Masculinity correlates positively with male strength and weight or body mass index (BMI). In fact, masculinity and BMI tend to load on the same component of trait perception. Therefore we predicted that individuals' perceptions of danger from violence will relate to preferences for facial cues to low-BMI. In two studies in Colombia, men and women from Bogota, Medellin, and surrounding communities were shown pairs of faces transformed to epitomize the shape correlates of men with high or low-BMI. The images were of European, Salvadoran, or Colombian men. Participants were asked to choose the face they considered most attractive. Subsequently, participants answered a survey about their health (e.g., frequency of illnesses the past year), media access (e.g., frequency of Internet use), education level (e.g., graduating from high school), and experiences/perceptions of violence in study 1 and about specific types of violence (public and domestic) in study 2. Results from both studies showed that women who experienced/perceived higher levels of violence preferred faces of low-BMI Salvadoran men. Preferences for low-BMI facial cues were significantly explained by violence (public or domestic), even after controlling for all other variables (including age, education, health, and media access). These results may reflect women's strategy to avoid male partners capable of inflicting harm.

The effect of sleep deprivation on objective and subjective measures of facial appearance.

The faces of people who are sleep deprived are perceived by others as looking paler, less healthy and less attractive compared to when well rested. However, there is little research using objective measures to investigate sleep-loss-related changes in facial appearance. We aimed to assess the effects of sleep deprivation on skin colour, eye openness, mouth curvature and periorbital darkness using objective measures, as well as to replicate previous findings for subjective ratings. We also investigated the extent to which these facial features predicted ratings of fatigue by others and could be used to classify the sleep condition of the person. Subjects (n = 181) were randomised to one night of total sleep deprivation or a night of normal sleep (8-9 hr in bed). The following day facial photographs were taken and, in a subset (n = 141), skin colour was measured using spectrophotometry. A separate set of participants (n = 63) later rated the photographs in terms of health, paleness and fatigue. The photographs were also digitally analysed with respect to eye openness, mouth curvature and periorbital darkness. The results showed that neither sleep deprivation nor the subjects' sleepiness was related to differences in any facial variable. Similarly, there was no difference in subjective ratings between the groups. Decreased skin yellowness, less eye openness, downward mouth curvature and periorbital darkness all predicted increased fatigue ratings by others. However, the combination of appearance variables could not be accurately used to classify sleep condition. These findings have implications for both face-to-face and computerised visual assessment of sleep loss and fatigue.

Social Transmission of Leadership Preference: Knowledge of Group Membership and Partisan Media Reporting Moderates Perceptions of Leadership Ability From Facial Cues to Competence and Dominance.

While first impressions of dominance and competence can influence leadership preference, social transmission of leadership preference has received little attention. The capacity to transmit, store and compute information has increased greatly over recent history, and the new media environment may encourage partisanship (i.e., "echo chambers"), misinformation and rumor spreading to support political and social causes and be conducive both to emotive writing and emotional contagion, which may shape voting behavior. In our pre-registered experiment, we examined whether implicit associations between facial cues to dominance and competence (intelligence) and leadership ability are strengthened by partisan media and knowledge that leaders support or oppose us on a socio-political issue of personal importance. Social information, in general, reduced well-established implicit associations between facial cues and leadership ability. However, as predicted, social knowledge of group membership reduced preferences for facial cues to high dominance and intelligence in out-group leaders. In the opposite-direction to our original prediction, this "in-group bias" was greater under less partisan versus partisan media, with partisan writing eliciting greater state anxiety across the sample. Partisanship also altered the salience of women's facial appearance (i.e., cues to high dominance and intelligence) in out-group versus in-group leaders. Independent of the media environment, men and women displayed an in-group bias toward facial cues of dominance in same-sex leaders. Our findings reveal effects of minimal social information (facial appearance, group membership, media reporting) on leadership judgments, which may have implications for patterns of voting or socio-political behavior at the local or national level.

Of urines and purines - a life in separation science.

This paper is a personal review of the role developments in separation science over the last four decades have played in the diagnosis and understanding of purine and pyridine metabolism particularly in man. In 1967 the separation of nucleotides was used to demonstrate a new chromatography technique. This technique became known as HPLC and which continues to dominate the analysis of purines etc. The resolution and quantitation offered by even the earliest HPLC systems completely changed our understanding of matters such as nucleotide instability in cells and tissues, diagnosis of in born errors, etc. Capillary Electrophoresis also enabled high resolution as well as the quantitation of usual analytes such allantoin. Now LC-MS dominates the diagnostic field. This paper is based on the Anne Simmonds Lecture given by the author at PP17 in Gdansk in 2017.

The Influence of Body Composition Effects on Male Facial Masculinity and Attractiveness.

Body mass index (BMI) and its facial correlates influence a range of perceptions including masculinity and attractiveness. BMI conflates body fat and muscle which are sexually dimorphic because men typically have more muscle but less fat than women. We therefore investigated the influence of facial correlates of body composition (fat mass and muscle mass) on the perception of masculinity in male faces. Women have been found to prefer more masculine looking men when considering short-term relationships compared with long-term relationships. We therefore conducted a second study of heterosexual women's preferences for facial correlates of fat and muscle mass under long and short relationship contexts. We digitally transformed face shape simulating the effects of raised and lowered levels of body fat or muscle, controlling for each other, height and age. In Study 1, participants rated masculinity of shape-transformed male faces. The face shape correlates of muscle mass profoundly enhanced perceived masculinity but the face shape correlates of fat mass only affected the perception of masculinity in underweight to low normal weight men. In Study 2, we asked two groups of women to optimize male face images (by adjusting the shape correlates of fat and muscle) to most resemble someone they would prefer, either for a short-term sexual relationship or for a long-term relationship. The results were consistent across the two participant groups: women preferred the appearance of male faces associated with a higher muscle mass for short-term compared with long-term relationships. No difference was found in women's preference for the face shape correlates of fat mass between the two relationship contexts. These findings suggest that the facial correlates of body fat and muscle have distinct impacts on the perception of male masculinity and on women's preferences. The findings indicate that body composition needs to be taken into consideration in psychological studies involving body weight.

Emotion-color associations in the context of the face.

Facial expressions of emotion contain important information that is perceived and used by observers to understand others' emotional state. While there has been considerable research into perceptions of facial musculature and emotion, less work has been conducted to understand perceptions of facial coloration and emotion. The current research examined emotion-color associations in the context of the face. Across 4 experiments, participants were asked to manipulate the color of face, or shape, stimuli along 2 color axes (i.e., red-green, yellow-blue) for 6 target emotions (i.e., anger, disgust, fear, happiness, sadness, surprise). The results yielded a pattern that is consistent with physiological and psychological models of emotion. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

First evidence of the conversion of paracetamol to AM404 in human cerebrospinal fluid.

Paracetamol is arguably the most commonly used analgesic and antipyretic drug worldwide, however its mechanism of action is still not fully established. It has been shown to exert effects through multiple pathways, some actions suggested to be mediated via N-arachidonoylphenolamine (AM404). AM404, formed through conjugation of paracetamol-derived p-aminophenol with arachidonic acid in the brain, is an activator of the capsaicin receptor, TRPV1, and inhibits the reuptake of the endocannabinoid, anandamide, into postsynaptic neurons, as well as inhibiting synthesis of PGE2 by COX-2. However, the presence of AM404 in the central nervous system following administration of paracetamol has not yet been demonstrated in humans. Cerebrospinal fluid (CSF) and blood were collected from 26 adult male patients between 10 and 211 minutes following intravenous administration of 1 g of paracetamol. Paracetamol was measured by high-performance liquid chromatography with UV detection. AM404 was measured by liquid chromatography-tandem mass spectrometry. AM404 was detected in 17 of the 26 evaluable CSF samples at 5-40 nmol⋅L-1. Paracetamol was measurable in CSF within 10 minutes, with a maximum measured concentration of 60 µmol⋅L-1 at 206 minutes. This study is the first to report on the presence of AM404 in human CSF following paracetamol administration. This may represent an important finding in our understanding of paracetamol's mechanism of action, although measured concentrations were far below the previously documented IC50 for this metabolite.