Competition-related factors directly influence preferences for facial cues of dominance in allies

Alliance formation is a critical dimension of social intelligence in political, social and biological systems. As some allies may provide greater ‘leverage’ than others during social conflict, the cognitive architecture that supports alliance formation in humans may be shaped by recent experience, for example in light of the outcomes of violent or non-violent forms intrasexual competition. Here we used experimental priming techniques to explore this issue. Consistent with our predictions, while men’s preference for dominant allies strengthened following losses (compared to victories) in violent intrasexual contests, women’s preferences for dominant allies weakened following losses (compared to victories) in violent intrasexual contests. Our findings suggest that while men may prefer dominant (i.e. masculine) allies following losses in violent confrontation in order to facilitate successful resource competition, women may ‘tend and befriend’ following this scenario and seek support from prosocial (i.e. feminine) allies and/or avoid the potential costs of dominant allies as long-term social partners. Moreover, they demonstrate facultative responses to signals related to dominance in allies, which may shape sex differences in sociality in light of recent experience and suggest that intrasexual selection has shaped social intelligence in humans

A sex difference in the context-sensitivity of dominance perceptions

Although dominance perceptions are thought to be important for effective social interaction, their primary function is unclear. One possibility is that they simply function to identify individuals who are capable of inflicting substantial physical harm, so that the perceiver can respond to them in ways that maximize their own physical safety. Another possibility is that they are more specialized, functioning primarily to facilitate effective direct (i.e., violent) intrasexual competition for mates, particularly among men. Here we used a priming paradigm to investigate these two possibilities. Facial cues of dominance were more salient to women after they had been primed with images of angry men, a manipulation known to activate particularly strong self-protection motivations, than after they had been primed with images of angry women or smiling individuals of either sex. By contrast, dominance cues were more salient to men after they had been primed with images of women than when they had been primed with images of men (regardless of the emotional expressions displayed), a manipulation previously shown to alter men's impressions of the sex ratio of the local population. Thus, men's dominance perceptions appear to be specialized for effective direct competition for mates, while women's dominance perceptions may function to maximize their physical safety more generally. Together, our results suggest that men's and women's dominance perceptions show different patterns of context-sensitivity and, potentially, shed new light on the routes through which violence and intrasexual competition have shaped dominance perceptions

The fish fauna of the Iwokrama Forest

Fishes were collected from the rivers in and around the Iwokrama Forest during January-February and November-December 1997. Four hundred species of fish were recorded from forty families in ten orders. Many of these fishes are newly recorded from Guyana and several are thought to be endemic. The number of species recorded for the area is surprising given the low level of effort and suggests that this area may be particularly important from a fish diversity perspective. This paper focuses on species of particular interest from a management perspective including those considered economically important, rare or endangered. The paper is also the basis for developing fisheries management systems in the Iwokrama Forest and Rupununi Wetlands

It’s the way he tells them (and who is listening):men’s dominance is positively correlated with their preference for jokes told by dominant-sounding men

While much research has explored humorous exchange in relation to mate choice, recent perspectives have emphasized the importance of humor for monitoring interest within social partnerships more generally. Indeed, given that similarity is thought to be important in the maintenance of social partnerships, we may expect humor appreciation to vary according to the degree of similarity between humor producers and recipients. In the current study we report evidence for such variation that is specific to men’s judgments of other men’s humor. Here we manipulated voice pitch in a set of ‘one-liner’ jokes to create low-pitched and high-pitched versions of men and women telling jokes. A composite measure of men’s own dominance was positively correlated with their preference for jokes told by other men with lowered voice pitch (a vocal cue to dominance). A follow-up study demonstrated that self-reported dominance was positively related to men’s choice of low-pitch men as friends when judging humorous audio clips but not when judging neutral control audio clips, suggesting that humor may be important in mediating the effect of dominance on friendship choice. These studies indicate systematic variation in humor appreciation related to friendship choices which may function to promote cohesion within male partnerships based on status

Sample-Efficient Model-Free Reinforcement Learning with Off-Policy Critics

Value-based reinforcement-learning algorithms provide state-of-the-art results in model-free discrete-action settings, and tend to outperform actor-critic algorithms. We argue that actor-critic algorithms are limited by their need for an on-policy critic. We propose Bootstrapped Dual Policy Iteration (BDPI), a novel model-free reinforcement-learning algorithm for continuous states and discrete actions, with an actor and several off-policy critics. Off-policy critics are compatible with experience replay, ensuring high sample-efficiency, without the need for off-policy corrections. The actor, by slowly imitating the average greedy policy of the critics, leads to high-quality and state-specific exploration, which we compare to Thompson sampling. Because the actor and critics are fully decoupled, BDPI is remarkably stable, and unusually robust to its hyper-parameters. BDPI is significantly more sample-efficient than Bootstrapped DQN, PPO, and ACKTR, on discrete, continuous and pixel-based tasks. Source code: https://github.com/vub-ai-lab/bdpi.Comment: Accepted at the European Conference on Machine Learning 2019 (ECML

Warming trends in summer heatwaves

The frequency and severity of heatwaves is expected to increase as the global climate warms. We apply crossing theory for the first time to determine heatwave properties solely from the distribution of daily observations without time‐correlation information. We use Central England Temperature timeseries to quantify how the simple increased occurrence of higher temperatures makes heatwaves (consecutive summer days with temperatures exceeding a threshold) more frequent and intense. We find an overall 2‐3‐fold increase in heatwave activity since the late 1800's. Week‐long heatwaves that on average return every 5 years were typically below ∼28°C and now typically exceed it. Our analysis takes as inputs average user‐specific heatwave properties. Its output pinpoints the range of temperatures for which changes in the distribution must be well‐resolved statistically in order to track how these heatwave properties are changing. This provides a quantitative benchmark for models used for the attribution of heatwaves

Perceptions of facial dominance, trustworthiness and attractiveness predict managerial pay awards in experimental tasks

Positive associations between physical attractiveness and employee reward are well-documented within the organisational literature. Although the impact of facial cues to trustworthiness and dominance on a number of social outcomes has been established outside of the workplace, the extent to which they, in addition to attractiveness, affect pay at different managerial levels is yet to be investigated. This paper presents research into this issue using a face payment task for shop floor managers (Retail Managers) and senior managers (Heads of Retail Operations). Evaluations indicated that all three facial cues were positively associated with awarded pay at both managerial levels. Moreover, attractiveness had a significantly stronger link with shop- floor managers' than senior managers' pay, whereas perceived trustworthiness and perceived dominance had significantly stronger links with pay for senior managers than shop-floor managers. It further emerged that women were paid more in this experimental task where pay was awarded solely based on facial features and that the facial features were more predictive of women's than men's pay. Awareness of the role of physical cues in pay awards can be considered by organisations to reduce biases in remuneration

School violence, school differences and school discourses

This article highlights one strand of a study which investigated the concept of the violenceresilient school. In six inner-city secondary schools, data on violent incidents in school and violent crime in the neighbourhood were gathered, and compared with school practices to minimise violence, accessed through interviews. Some degree of association between the patterns of behaviour and school practices was found: schools with a wider range of wellconnected practices seemed to have less difficult behaviour. Interviews also showed that the different schools had different organisational discourses for construing school violence, its possible causes and the possible solutions. Differences in practices are best understood in connection with differences in these discourses. Some of the features of school discourses are outlined, including their range, their core metaphor and their silences. We suggest that organisational discourse is an important concept in explaining school effects and school differences, and that improvement attempts could have clearer regard to this concept

Ambulatory Care Skills: Do Residents Feel Prepared?

Abstract: Objective: To determine resident comfort and skill in performing ambulatory care skills. Methods: Descriptive survey of common ambulatory care skills administered to internal medicine faculty and residents at one academic medical center. Respondents were asked to rate their ability to perform 12 physical exam skills and 6 procedures, and their comfort in performing 7 types of counseling, and obtaining 6 types of patient history (4 point Likert scale for each). Self-rated ability or comfort was compared by gender, status (year of residency, faculty), and future predicted frequency of use of the skill. Results: Residents reported high ability levels for physical exam skills common to both the ambulatory and hospital setting. Fewer felt able to perform musculoskeletal, neurologic or eye exams easily alone. Procedures generally received low ability ratings. Similarly, residents’ comfort in performing common outpatient counseling was also low. More residents reported feeling very comfortable in obtaining history from patients. We found little variation by gender, year of training, or predicted frequency of use. Conclusion: Self-reported ability and comfort for many common ambulatory care skills is low. Further evaluation of this finding in other training programs is warranted