Papers by Sonja Windhager
Face to Face
Human Nature, Sep 20, 2008
Perception of strength, attractiveness and aggressiveness of Maasai male faces calibrated to handgrip strength: Evidence from a European sample
American Journal of Human Biology
ObjectivesPrevious research showed that male and female members of the Maasai from Northern Tanza... more ObjectivesPrevious research showed that male and female members of the Maasai from Northern Tanzania judge images of facial morphs calibrated to greater handgrip strength (HGS) higher on strength and attractiveness, but lower on aggressiveness than those calibrated to lower HGS. The accurate assessment of male physical strength from facial information may be adaptive as suggested by the evidence on health and fitness‐related benefits linked to high muscular strength.MethodsThis study extends previous work by obtaining European female (n = 220) and male (n = 51) assessments of HGS‐calibrated Maasai male faces. Participants rated five facial morphs for strength, attractiveness, and aggressiveness on computer screens.ResultsPerceived physical strength increased with morphs calibrated to higher HGS. The lowest and highest HGS morphs were judged lower in attractiveness than the others, and rated aggressiveness decreased in morphs calibrated to higher HGS.ConclusionsGiven the high similar...
Symmetry
Differentiation in the defensive armor of the threespine stickleback, Gasterosteus aculeatus, is ... more Differentiation in the defensive armor of the threespine stickleback, Gasterosteus aculeatus, is caused by predator-driven divergent selection. Most studies considered armor traits related to swimming behavior, hence combining pre- and post-capture responses to gape-limited predators. Here, we focus exclusively on the defensive complex (DC), the post-capture predator defense. This complex consists of a series of bony elements surrounding the anterior part of the abdomen. Relaxation from predation pressure not only drives reduction of bony elements but is also expected to increase asymmetry in the DC. To test this hypothesis, we used four Austrian freshwater populations that differed distinctly in the formation of the DC. We found significant left–right asymmetries in the DC in the population with a distinctly reduced DC and, surprisingly, also in the population with a significantly enhanced DC. These populations occur in vastly different habitats (stream and lake) characterized by d...
Additional details. from Handgrip strength and 2D : 4D in women: homogeneous samples challenge the (apparent) gender paradox
Assessment of the second-to-fourth digit ratio (2D:4D) and reliability; Partial correlations for ... more Assessment of the second-to-fourth digit ratio (2D:4D) and reliability; Partial correlations for 2D:4D with handgrip strength; Histograms for the 2D:4D right–left differences per handedness group; 2D:4D as a biomarker for prenatal testosterone exposure.
Butovskaya et al. Facial cues to physical strength increase attractiveness but decrease aggressiveness assessments in male Maasai of Northern Tanzania
Data set corresponding to Butovskaya et al. – Facial cues to physical strength increase attractiv... more Data set corresponding to Butovskaya et al. – Facial cues to physical strength increase attractiveness but decrease aggressiveness assessments in male Maasai of Northern Tanzania – in Evolution and Human Behavior (https://doi.org/10.1016/j.evolhumbehav.2021.11.006). <br>
Procrustes shape coordinates
Facial masculinity concepts reconsidered: a tribute to biology
Masculinity is an important and omnipresent trait in face research. Different approaches were app... more Masculinity is an important and omnipresent trait in face research. Different approaches were applied to quantify phenotypic masculinity in order to study its relationship to various behaviors and social perception in humans. In this presentation, we compare the most prevalent concepts and discuss their biological interpretation. Furthermore, facial allometry (i.e., the dependence of shape on size) is entered into this comparison. These concepts include perceived masculinity, hormone-mediated masculinity, average morphological sexual dimorphism, linear discriminant function, and allometric versus non-allometric sexual dimorphism. Their quantification and facial patterns will be exemplified using a sample of standardized frontal photographs of 21 women and 24 men (aged 20-34 years) from Austria. Seventy landmarks and semilandmarks were digitized and subjected to a Generalized Procrustes Analysis. The male faces were rated for perceived masculinity on a continuous scale ranging from “...
Visualization of the association of handgrip strength (HGS) with the corresponding facial shape scores within age-sex groups
The Perception of Automotive Designs
Over evolutionary time, humans have developed a selective sensitivity to features in the human fa... more Over evolutionary time, humans have developed a selective sensitivity to features in the human face that convey information on sex, age, emotions, and intentions. This ability might not only be applied to our conspecifics nowadays, but also to other living objects (i.e., animals) and even to artificial structures, such as cars. To investigate this possibility, we asked people to report the characteristics, emotions, personality traits, and attitudes they attribute to car fronts, and we used geometric morphometrics (GM) and multivariate statistical methods to determine and visualize the corresponding shape information. Automotive features and proportions are found to covary with trait perception in a manner similar to that found with human faces. Emerging analogies are discussed. This study should have implications for both our understanding of our prehistoric psyche and its interrelation with the modern world.
Regressions of mid-facial FA and TA on demographic and genotype data (<i>n</i> = 3215)
<p>FA and TA were each regressed on the 5 SNPs (rs4648379, rs974448, rs17447439, rs6555969,... more <p>FA and TA were each regressed on the 5 SNPs (rs4648379, rs974448, rs17447439, rs6555969, rs805722), sex, age, HL and cohort. Genotypes are encoded accordingly to Liu et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099009#pone.0099009-Liu1" target="_blank">[1]</a>: 0 = AA, 1 = AB and 2 = BB (their suppl. table 6).</p
PC scores of texture
Principal component scores of facial texture (RGB values of the pixels of the standardized images... more Principal component scores of facial texture (RGB values of the pixels of the standardized images) for the 49 individuals
Landmarks, stature, and masculinity ratings for 45 human faces
Females_21_70lms.txt: x and y coordinates of 70 landmarks measured on 21 female faces (21x140 dat... more Females_21_70lms.txt: x and y coordinates of 70 landmarks measured on 21 female faces (21x140 data matrix) Males_24_70lms: x and y coordinates of 70 landmarks measured on 24 male faces (24x140 data matrix) Scale_factor_females.txt: scale factor of landmark coordinates for the female faces. Scale_factor_males.txt: scale factor of landmark coordinates for the male faces. Body_height_males_cm.txt: Measures of stature for the 24 male individuals (in cm). Perceived_masculinity.txt: Average masculinity ratings for the 24 male faces (range from 0 to 80)
Data from: The morphometrics of "masculinity" in human faces
In studies of social inference and human mate preference, a wide but inconsistent array of tools ... more In studies of social inference and human mate preference, a wide but inconsistent array of tools for computing facial masculinity has been devised. Several of these approaches implicitly assumed that the individual expression of sexually dimorphic shape features, which we refer to as maleness, resembles facial shape features perceived as masculine. We outline a morphometric strategy for estimating separately the face shape patterns that underlie perceived masculinity and maleness, and for computing individual scores for these shape patterns. We further show how faces with different degrees of masculinity or maleness can be constructed in a geometric morphometric framework. In an application of these methods to a set of human facial photographs, we found that shape features typically perceived as masculine are wide faces with a wide inter-orbital distance, a wide nose, thin lips, and a large and massive lower face. The individual expressions of this combination of shape features—the masculinity shape scores—were the best predictor of rated masculinity among the compared methods (r = 0.5). The shape features perceived as masculine only partly resembled the average face shape difference between males and females (sexual dimorphism). Discriminant functions and Procrustes distances to the female mean shape were poor predictors of perceived masculinity
Scientific reports, Jan 15, 2018
Prosocial behaviour (i.e., voluntary behaviour intended to benefit another) seems to be fully dev... more Prosocial behaviour (i.e., voluntary behaviour intended to benefit another) seems to be fully developed in children by the age of 6 years. However, questions about which factors modify prosocial behaviour at that age remain understudied. Here we used a resource allocation paradigm to test prosocial behaviour in 6-9-year-old school children. They could decide between a "selfish" (i.e., one sticker for themselves) and a "prosocial" option (i.e., one sticker for themselves and one for the receiver) and we tested whether friendship, social status and prenatal androgen exposure (approximated by the 2nd to 4th digit ratio; 2D:4D) influenced children's prosocial choices. We found that children behaved prosocially, and that their prosocial tendencies were negatively correlated with prenatal androgen exposure; i.e., children with high 2D:4D ratios (reflecting low prenatal androgen exposure) acted more prosocially than children with low 2D:4D ratios. Further, their soc...
Scientific reports, Jan 27, 2018
Studies of human social perception become more persuasive when the behavior of raters can be sepa... more Studies of human social perception become more persuasive when the behavior of raters can be separated from the variability of the stimuli they are rating. We prototype such a rigorous analysis for a set of five social ratings of faces varying by body fat percentage (BFP). 274 raters of both sexes in three age groups (adolescent, young adult, senior) rated five morphs of the same averaged facial image warped to the positions of 72 landmarks and semilandmarks predicted by linear regression on BFP at five different levels (the average, ±2 SD, ±5 SD). Each subject rated all five morphs for maturity, dominance, masculinity, attractiveness, and health. The patterns of dependence of ratings on the BFP calibration differ for the different ratings, but not substantially across the six groups of raters. This has implications for theories of social perception, specifically, the relevance of individual rater scale anchoring. The method is also highly relevant for other studies on how biologica...
Scientific Reports, 2017
This article exploits a method recently incorporated in the geometric morphometric toolkit that c... more This article exploits a method recently incorporated in the geometric morphometric toolkit that complements previous approaches to quantifying the facial features associated with specific body characteristics and trait attribution during social perception. The new method differentiates more globally encoded from more locally encoded information by a summary scaling dimension that is estimated by fitting a line to the plot of log bending energy against log variance explained, partial warp by partial warp, for some sample of varying shapes. In the present context these variances come from the regressions of shape on some exogenous cause or effect of form. We work an example involving data from male faces. Here the regression slopes are steepest, and the sums of explained variances over the uniform component, partial warp 1 and partial warp 2 are greatest, for the conventional body mass index, followed by cortisol and, lastly, perceived health. This suggests that physiological characteristics may be represented at larger scale (global patterns), whereas cues in perception are of smaller scale (local patterns). Such a polarity within psychomorphospace, the global versus the focal, now has a metric by which patterns of morphology can be modeled in both biological and psychological studies. "Human facial diversity is substantial, complex, and largely scientifically unexplained" 1. The human face is an important source of information for social interactions and for scientists alike. A face advertises, among other things, a person's sex, age, hormonal status, previous environmental exposure, health, interpersonal attitudes, and emotions. The study of faces and what they communicate in this way integrates genomics, human behavioral biology and life history, evolutionary psychology, and biological anthropology. Ultimately the theory of these relationships is an evolutionary one: that the human body and face have been shaped by selective forces throughout our evolutionary history in response to natural and social environments. Facial morphology thereby occupies the middle of a causal chain whereby biological factors such as age, sex, and body composition are reflected in facial and bodily characteristics that then serve as cues in person perception and the consequent behaviors. Correlational studies have identified some links between physical characteristics and social inference, but usually fail to identify the specific morphological pathways underlying the inferences. Morphometric face analysis, however, has demonstrated that quantification of the morphological cues is crucial 2-4. For studying correlates of facial shape variation, researchers are now turning to geometric morphometric (GMM) methods, which can combine biological factors, shape information, and trait inference in the same data space. In 2005, Schaefer and colleagues were the first to make use of this possibility in the analysis of faces 5-7. In Schaefer et al. 2009, the approach was made explicit in a review article and given the name "psychomorphospace" 8. Since then GMM has been applied in face research by several research groups, e.g., refs 9-12.
PloS one, 2017
Facial markers of body composition are frequently studied in evolutionary psychology and are impo... more Facial markers of body composition are frequently studied in evolutionary psychology and are important in computational and forensic face recognition. We assessed the association of body mass index (BMI) and waist-to-hip ratio (WHR) with facial shape and texture (color pattern) in a sample of young Middle European women by a combination of geometric morphometrics and image analysis. Faces of women with high BMI had a wider and rounder facial outline relative to the size of the eyes and lips, and relatively lower eyebrows. Furthermore, women with high BMI had a brighter and more reddish skin color than women with lower BMI. The same facial features were associated with WHR, even though BMI and WHR were only moderately correlated. Yet BMI was better predictable than WHR from facial attributes. After leave-one-out cross-validation, we were able to predict 25% of variation in BMI and 10% of variation in WHR by facial shape. Facial texture predicted only about 3-10% of variation in BMI a...
Evolutionary Psychology, 2016
Research on cooperation has contributed to a better understanding of the foundations of human soc... more Research on cooperation has contributed to a better understanding of the foundations of human social behavior. Most studies, however, have not considered fundamental social parameters such as an individual's position in a social hierarchy. As a first step, this study investigates the modulating effects of socioeconomic status (SES) on behavior and the physiological stress response. Study participants (n ¼ 83) played a cooperative game with computerized coplayers of four categories: similar or higher SES in combination with either high or low fairness in behavior (i.e., willingness to cooperate). All participants showed a significant increase in saliva cortisol after the game compared to a control group. Only when paired with higher SES coplayers, however, did participants show a significant subsequent decrease in cortisol concentrations. Participants' behavior in response to a coplayer's decisions was only affected by the degree of fairness, but not the SES, of respective coplayers. Physiologically, playing this cooperation game was a big challenge for participants as measured by salivary cortisol. Yet, the high recovery rate when playing with cooperative, higher status individuals showed the stress-protective effects of positive social interactions in the framework of social hierarchies.
BMC Evolutionary Biology, 2015
Background: The evolutionary highly conserved neurohypophyseal hormones oxytocin and arginine vas... more Background: The evolutionary highly conserved neurohypophyseal hormones oxytocin and arginine vasopressin play key roles in regulating social cognition and behaviours. The effects of these two peptides are meditated by their specific receptors, which are encoded by the oxytocin receptor (OXTR) and arginine vasopressin receptor 1a genes (AVPR1A), respectively. In several species, polymorphisms in these genes have been linked to various behavioural traits. Little, however, is known about whether positive selection acts on sequence variants in genes influencing variation in human behaviours. Results: We identified, in both neuroreceptor genes, signatures of balancing selection in the cis-regulative acting sequences such as transcription factor binding and enhancer sequences, as well as in a transcriptional repressor sequence motif. Additionally, in the intron 3 of the OXTR gene, the SNP rs59190448 appears to be under positive directional selection. For rs59190448, only one phenotypical association is known so far, but it is in high LD' (>0.8) with loci of known association; i.e., variants associated with key pro-social behaviours and mental disorders in humans. Conclusions: Only for one SNP on the OXTR gene (rs59190448) was a sign of positive directional selection detected with all three methods of selection detection. For rs59190448, however, only one phenotypical association is known, but rs59190448 is in high LD' (>0.8), with variants associated with important pro-social behaviours and mental disorders in humans. We also detected various signatures of balancing selection on both neuroreceptor genes.
PloS one, 2015
In studies of social inference and human mate preference, a wide but inconsistent array of tools ... more In studies of social inference and human mate preference, a wide but inconsistent array of tools for computing facial masculinity has been devised. Several of these approaches implicitly assumed that the individual expression of sexually dimorphic shape features, which we refer to as maleness, resembles facial shape features perceived as masculine. We outline a morphometric strategy for estimating separately the face shape patterns that underlie perceived masculinity and maleness, and for computing individual scores for these shape patterns. We further show how faces with different degrees of masculinity or maleness can be constructed in a geometric morphometric framework. In an application of these methods to a set of human facial photographs, we found that shape features typically perceived as masculine are wide faces with a wide inter-orbital distance, a wide nose, thin lips, and a large and massive lower face. The individual expressions of this combination of shape features--the...
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Papers by Sonja Windhager