Moral opportunism: A unique genetic grounding associates lesser guilt from perpetrating injustice with greater sensitivity to being the victim of it. Nikolai Haahjem Eftedal, Thomas Haarklau Kleppestø, Nikolai Olavi Czajkowski, Jonas Kunst, Espen Røysamb, Olav Vassend, Eivind Ystrøm, Lotte Thomsen. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y
People vary in their general propensity to perceive and react to injustice. However, moral rules of justice may be gamed through selective endorsement depending on one’s own role as victim or perpetrator. Here, we demonstrate a unique genetic grounding for this latter strategy (as well as for injustice sensitivity in general). The Justice Sensitivity (JS) scale distinguishes between four sub-types of injustice sensitivity. A perceiver of an injustice can either be a victim, an observer, a beneficiary, or a perpetrator to this injustice, and sensitivity to these facets correlate robustly. We use a genetically informative sample of 544 monozygotic- and 736 dizygotic twin pairs to estimate the etiological sources of these associations, analyzing the underlying factor structure while separating the contributions of genetic- versus environmental influences. We find evidence for two substantially heritable latent traits influencing responses across the JS-facets: 1) a generalized injustice sensitivity factor leading to increased sensitivity to injustices of all categories, and 2) a moral opportunism factor causing increased victim sensitivity combined with a decreased propensity to feel guilt from being the perpetrator. This latter moral opportunism factor shares further genetic underpinnings with social dominance orientation.
Be fair: Do explicit norms promote fairness in children? Gorana T. Gonzalez, Katherine J. McAuliffe. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y
Abstract: Children have an early-emerging expectation that resources should be divided fairly amongst agents (e.g. Sommerville et al., 2013), yet their behavior does not begin to align with these expectations until later in development. This dissociation between knowledge and behavior (Blake, McAuliffe, & Warneken, 2014) raises important questions about the mechanisms that encourage children to behave how they know they should behave. Here we tested whether explicitly invoking fairness norms encourages costly fair decisions in 4- to 9-year-old-children. We examine children’s responses to unequal resource allocations in the Inequity Game (Blake & McAuliffe, 2011) by varying the direction of inequity (advantageous vs disadvantageous inequity) and normative information (to be fair or to act autonomously). Our results show children are more likely to reject advantageous allocation in the fairness norm condition than in the autonomous choice condition, but we do not see this difference when children are presented with disadvantageous allocations. This study showcases children’s costly fairness norm enforcement as a flexible process, one that can be brought in and out of alignment with their knowledge of fairness by shining a spotlight on how one ought to behave.
Religion causes decreases in women’s provocativeness of dress. Liana S. E. Hone, Michael E. McCullough. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y
Abstract: Long-term mating strategies are associated with greater religiosity and studies demonstrate that exposure to religious stimuli down-regulate traits associated with short-term mating strategies in men. Based on tentative evidence that women might also occasionally pursue short-term mating strategies, we evaluated the effects of religiosity on a trait associated with women’s mating strategies: Provocativeness of dress (POD). We predicted that women’s baseline religiosity would be negatively correlated with their POD (measured via skin exposure) on the premise that POD is typically associated with women’s short-term mating strategies. We also predicted that women who completed a religious writing task would illustrate less skin exposure than their peers when asked what they would wear to a hypothetical social gathering with attractive members of the opposite sex in attendance. In a sample of 817 participants, women who classified themselves as highly religious exposed less skin in their day-today lives. Likewise, women who completed a religious writing task illustrated less skin exposure than did their peers. A significant religiosity by writing task condition assignment interaction indicated that the religious writing task was more effective in reducing skin exposure for highly religious participants than it was for less religious participants.
Facial aging trajectories: A common shape pattern in male and female faces is disrupted after menopause. Sonja Windhager et al. American Journal of Physical Anthropology, June 12 2019. https://doi.org/10.1002/ajpa.23878
Abstract
Objectives: Despite variation in lifestyle and environment, first signs of human facial aging show between the ages of 20–30 years. It is a cumulative process of changes in the skin, soft tissue, and skeleton of the face. As quantifications of facial aging in living humans are still scarce, we set out to study age‐related changes in three‐dimensional facial shape using geometric morphometrics.
Materials and methods: We collected surface scans of 88 human faces (aged 26–90 years) from the coastal town Split (Croatia) and neighboring islands. Based on a geometric morphometric analysis of 585 measurement points (landmarks and semilandmarks), we modeled sex‐specific trajectories of average facial aging.
Results: Age‐related facial shape change was similar in both sexes until around age 50, at which time the female aging trajectory turned sharply. The overall magnitude of facial shape change (aging rate) was higher in women than men, especially in early postmenopause. Aging was generally associated with a flatter face, sagged soft tissue (“broken” jawline), deeper nasolabial folds, smaller visible areas of the eyes, thinner lips, and longer nose and ears. In postmenopausal women, facial aging was best predicted by the years since last menstruation and mainly attributable to bone resorption in the mandible.
Discussion: With high spatial and temporal resolution, we were able to extract a shared facial aging pattern in women and men, and its divergence after menopause. This fully quantitative three‐dimensional analysis of human facial aging may not only find applications in forensic and ancient human facial reconstructions, but shall include lifestyle and endocrinological measures, and also reach out to studies of social perception.
[Full text and charts at the link above]
1 INTRODUCTION
Throughout life, facial shape changes systematically due to growth, maturation, and senescence. What we see on the surface is the joint effect of aging and other processes in several tissue layers. Despite variation in lifestyle and environment, the first signs of facial aging become apparent between the ages of 20 and 30 (Albert, Ricanek Jr., & Patterson, 2007; Windhager & Schaefer, 2016). Facial aging results from cumulative age‐related changes in the skin, soft tissue, and skeleton of the face (Mendelson & Wong, 2012). Its manifestations reflect the combined effects of gravity, facial volume loss, progressive bone resorption, decreased tissue elasticity, and redistribution of fat (Coleman & Grover, 2006). In this article, we focus on age‐related changes in facial shape, leaving aside changes that occur in facial texture, color, and amount of facial hair. Quantifying aging patterns is not only crucial in the fields of facial reconstruction and aesthetic rejuvenation, but is also important in studies of facial recognition as well as interpersonal perception and stereotyping.
In the centennial anniversary issue of this journal, Bogin, Varea, Hermanussen, and Scheffler (2018) have just updated the Bogin classification system of human life history stages. In our study, we focus on those stages underrepresented in the physical anthropological literature (Ice, 2003): gradual decline (35–50 years), transition/degeneration age (>50 years to senescence), and senescence/old age, which shows variable onset and progression as a function of prior levels of somatic and cognitive reserves. Also, Kirkwood (2017) stresses the variability of aging, caused by “a process of progressive accumulation of defects that stem ultimately from random damage” (p. 1070). Despite individual variation in onset and progression, human facial aging shows a common pattern of morphological, histological, and dermatological changes, as addressed in numerous biomedical studies (Figure 1). Bone tissues along the orbital rim, especially superomedially and inferolaterally, have been shown to recede with increasing age, while the central orbital parts remain relatively stable throughout life (Kahn & Shaw Jr., 2008). This contributes to a more prominent medial fat pad, elevated medial brows, and the typical lengthening of the lid‐cheek junction in older age (Mendelson & Wong, 2012). Retrusion of the bony midface and the maxilla in adds to building and deepening the nasolabial folds and to increasing facial flatness (Pessa et al., 1998; Shaw Jr. & Kahn, 2007). The lengthening of the nose results from an enlargement of the piriform aperture as the bony edges recede, especially in the ascending process of the maxilla. Together with reduced soft‐tissue laxity, this also leads to a drooping nose tip (Rohrich, Hollier Jr., Janis, & Kim, 2004; Shaw Jr. & Kahn, 2007). Moreover, the height and length of the mandible decrease in older ages, whereas the mandibular angle increases (Shaw Jr. et al., 2010). Mendelson and Wong (2012), however, noted that these standard linear measures fail to identify in‐between areas of reduced facial projection, such as the mandible's prejowl region, which becomes more concave with increasing age (Pessa, Slice, Hanz, Broadbent Jr., & Rohrich, 2008; Romo, Yalamanchili, & Sclafani, 2005; Zimbler, Kokoska, & Thomas, 2001).
Example facial surface scan with aging‐related
features labeled. They are the combined result of skeletal and
soft‐tissue alterations and robust age markers in both sexes. Lines and
wrinkles are signs of aging too, yet their locations across individual
faces are more variable, so that they average out in studies of
age‐specific average shapes like ours. Also, they are more susceptible
to lifestyle and environmental influences. The 3D model of the example
face is publicly available from Artec 3D (https://www.artec3d.com/de/3d‐models/gesichtsscan)
Collagen fibers are responsible for the resilience and main
mass of the dermis. Males have more collagen than females throughout
adult life (Shuster, Black, & McVitie, 1975). With increasing age, the amount, quality, and type of collagen change (Galea & Brincat, 2000; Shuster et al., 1975).
In both sexes, total skin collagen and skin thickness decrease. Yet,
especially after menopause, collagen becomes reduced both in the skin
and bone of female faces. Experimental estrogen administration increases
skin thickness (as summarized by Brincat, Baron, & Galea, 2005), but mice models indicate that also androgen contributes to the thicker male skin (Markova et al., 2004).
The amount and distribution of subcutaneous fat further
contribute to the observable facial shape. This fat is thicker
(especially in the medial cheek) and more unevenly distributed in the
female than in the male face (Keaney, 2016).
With increasing age, however, soft tissue thickness decreases,
especially between 20 and 60 years (Wysong, Joseph, Kim, Tang, &
Gladstone, 2013).
Midfacial ptosis is further enhanced by muscle loss and progressive
muscle shortening and straightening (Buchanan & Wulc, 2015). Donofrio (2000)
ascribed the physical appearance of tissue sagging to either too little
or too much fat (hence the term “sagging paradox”): fat is stored
diffusely in young faces, but older faces pocket fat in distinct areas.
Such processes also account for ptosis of the brows and eyelid drooping,
which already become apparent before age 30 (Zimbler et al., 2001).
Human lips also change throughout adulthood. Dryness
increases with age and is higher on the lower lip than on the upper one
(Lévêque & Goubanova, 2004). In a qualitative illustration of an aged face, Zimbler et al. (2001)
described upper lip flattening and lengthening as well as a thinning
and atrophy of the vermilion (red lip). Like the lips, the external ear
is built solely from soft tissue. Total ear height increases with age
mainly due to lobal height increase in both sexes (Asai, Yoshimura,
Nago, & Yamada, 1996; Brucker, Patel, & Sullivan, 2003). Heathcote (1995) reported a lengthening of the ear by 0.22 mm per year in a cross‐sectional study of people aged 30–93 years.
Based on linear measurements of facial photographs of the same person at two ages, Pitanguy et al. (1998)
derived a second‐order polynomial model to best fit the ptosis of the
midfacial tissues in women with increasing age. Leta, Pamplona, Weber,
Conci, and Pitanguy (2000)
extended this approach toward lateral views, and both research teams
further support most of the above‐described soft‐tissue patterns
regarding eyes, lips, and ears in Brazilian patients of European
descent. Schmidlin, Steyn, Houlton, and Briers (2018)
obtained similar results in African faces and graphed their values in
relation to the work of Sforza and colleagues in Italian faces. They
confirmed the overall pattern, notwithstanding absolute thickness
differences between the populations at a given age stage.
Despite some recent efforts to quantify age‐related shape features of the face beyond single regions (Chen et al., 2015; Mydlová, Dupej, Koudelová, & Velemínská, 2015),
the evidence is still largely qualitative for faces of living humans.
Combining the scarce quantitative studies is also hindered by the
diverse ethnic backgrounds of the participants in these studies (Vashi,
Buainain De Castro Maymone, & Kundu, 2016).
Therefore, we set out to study age‐related facial shape changes in
adults using a geometric morphometric approach. More specifically, we
transferred—for the first time—the geometric morphometric toolkit of
physical anthropology and its study of growth trajectories (Bulygina,
Mitteroecker, & Aiello, 2006; Coquerelle et al., 2011; Mitteroecker, Gunz, Bernhard, Schaefer, & Bookstein, 2004)
to human facial aging, including soft tissue. We study changes in
appearance with chronological age in a genetically and environmentally
homogeneous group from two Croatian islands and a near‐by coastal town,
based on three‐dimensional facial surface scans. Local linear
regressions allow for an unprecedentedly high temporal and spatial
resolution.
A competitive drive? Same‐sex attentional preferences in capuchins. Elizabeth V. Lonsdorf, Lindsey M. Engelbert, Lauren H. Howard. American Journal of Primatology, June 12 2019. https://doi.org/10.1002/ajp.22998
Abstract: In primates, faces provide information about several characteristics of social significance, including age, physical health, and biological sex. However, despite a growing literature on face processing and visual attention in a number of primate species, preferences for same‐ or opposite‐sex faces have not yet been examined. In the current study, we explore the role of conspecific sex on visual attention in two groups of capuchin monkeys. Subjects were shown a series of image pairs on a Tobii Pro TX300 eye tracker, each depicting an unfamiliar male and an unfamiliar female face. Given the behavioral evidence of mate choice in both sexes, we hypothesized that capuchins would preferentially attend to images of unfamiliar conspecifics of the opposite sex. Our alternative hypothesis was that capuchins would preferentially attend to same‐sex individuals to assess potential competitors. Our results provide support for our alternative hypothesis. When comparing attention to each stimuli type across sexes, females spent significantly larger percentages of time than males looking at female photos, whereas males spent significantly larger percentages of time than females looking at male photos. Within each sex, females looked for significantly larger percentages of time to female versus male images. Males also looked for larger percentages of time to same‐sex images, though not significantly. To our knowledge, these data are the first to demonstrate significant sex‐biased attentional preferences in adult primates of any species, and suggest that, for capuchins, potential competitors garner more attention than potential mates. In addition, our findings have implications for studies of visual attention and face processing across the primate order, and suggest that researchers need to control for these demographic factors in their experimental designs.
HIGHLIGHTS Capuchins exhibit preferential attention to images of same‐sex faces. Female capuchins look significantly more at unfamiliar female images. Male capuchins look significantly more at unfamiliar male images.
Testing popular news discourse on the “echo chamber” effect: Does political polarisation occur among those relying on social media as their primary politics news source? An Nguyen, Hong Tien Vu. First Monday, Volume 24, Number 6 - 3 June 2019. https://doi.org/10.5210/fm.v24i6.9632
Abstract: Since 2016, online social networks (OSNs), especially their “big data” algorithms, have been intensively blamed in popular news discourse for acting as echo chambers. These chambers entrap like-minded voters in closed ideological circles that cause serious damage to democratic processes. This study examines this “echo chamber” argument through the rather divisive case of EU politics among EU citizens. Based on an exploratory secondary analysis of the Eurobarometer 86.2 survey dataset, we investigate whether the reliance on OSNs as a primary EU political news source can lead people to more polarisation in EU-related political beliefs and attitudes than a reliance on traditional media. We found little evidence for this polarisation, lending credence to a rejection of social media’s “echo chamber” effect.
Resource accessibility and intrasexual competition: Does a lack of direct access to resources drive covert strategies? Nicole Hudson, Jessica D. Ayers, Athena Aktipis. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y
Abstract: Males are thought to compete directly in same-sex competition while females are thought to compete more indirectly (Campbell, 1999). By using a covert approach, women can often compete with rivals (undetected) through gossip and reputation derogation. Men, however, often risk retaliation for the possible status benefits - leading to a potential increase in reproductive success. (Campbell, 1999). Research has yet to investigate if traditional sex differences in competitive strategies are influenced by whether resources can be acquired directly or indirectly. We hypothesized that individuals will endorse covert tactics when resources can be obtained indirectly and overt tactics when resources can be obtained directly. To assess this, participants read vignettes that described a summer internship with direct access or indirect access to one post-internship job and answered questions to assess competition strategies. When this opportunity was attainable indirectly through another individual, we predicted that both men and women would use more covert tactics. On the other hand, when the opportunity was directly attainable based on individual performance, we expected both men and women to use more overt tactics. Our results could have implications for the reduction of harmful workplace behaviors and misperceptions (i.e., men confusing women’s competition tactics for mating signals).
What are rules for? Fundamental motives of social rules. Jung Yul Kwon, Michael Barlev, Douglas T. Kenrick, Michael E.W. Varnum. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y
Abstract: What do people think social norms for? At the group level, mutually agreed upon rules or expectations of appropriate social behavior serve to solve coordination problems and maintain order in society. At the individual level, people may perceive norms to facilitate achieving desired outcomes in various life domains, which leads to increased probability of reproductive success. We examined how people construe social norms in terms of their relevance to fundamental social motives. In the first study, U.S. participants free-listed ten social rules they considered important, and then rated how relevant each rule was for achieving positive outcomes in the fundamental social motive domains. In subsequent studies, rather than generating their own rules, participants were given a well-known set of rules in society to rate. Across these studies, we consistently found that rules on average were rated as being most relevant for affiliating with a group, followed by avoiding exclusion, achieving/maintaining status, and kin care.
Finding Common Ground in Meta-Analysis “Wars” on Violent Video Games. Maya B. Mathur, Tyler J. VanderWeele. Perspectives on Psychological Science, June 12, 2019. https://doi.org/10.1177/1745691619850104
Abstract: Independent meta-analyses on the same topic can sometimes yield seemingly conflicting results. For example, prominent meta-analyses assessing the effects of violent video games on aggressive behavior have reached apparently different conclusions, provoking ongoing debate. We suggest that such conflicts are sometimes partly an artifact of reporting practices for meta-analyses that focus only on the pooled point estimate and its statistical significance. Considering statistics that focus on the distributions of effect sizes and that adequately characterize effect heterogeneity can sometimes indicate reasonable consensus between “warring” meta-analyses. Using novel analyses, we show that this seems to be the case in the video-game literature. Despite seemingly conflicting results for the statistical significance of the pooled estimates in different meta-analyses of video-game studies, all of the meta-analyses do in fact point to the conclusion that, in the vast majority of settings, violent video games do increase aggressive behavior but that these effects are almost always quite small.
Keywords: meta-analysis, effect sizes, video games, aggression
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