Sex differences in intellectual performance: analysis of a large cohort of competitive chess players

Only 1% of the world's chess grandmasters are women. This underrepresentation is unlikely to be caused by discrimination, because chess ratings objectively reflect competitive results. Using data on the ratings of more than 250,000 tournament players over 13 years, we investigated several potential explanations for the male domination of elite chess. We found that (a) the ratings of men are higher on average than those of women, but no more variable; (b) matched boys and girls improve and drop out at equal rates, but boys begin chess competition in greater numbers and at higher performance levels than girls; and (c) in locales where at least 50% of the new young players are girls, their initial ratings are not lower than those of boys. We conclude that the greater number of men at the highest levels in chess can be explained by the greater number of boys who enter chess at the lowest levels.     

The impact of politeness and relationship on perceived quality of advice about a problem

Advice is a common but potentially problematic way to respond to someone who is distressed. Politeness theory (Brown & Levinson, 1987) suggests advice threatens a hearer's face and predicts that the speaker‐hearer relationship and the use of politeness strategies can mitigate face threat and enhance the effectiveness of advice messages. Students (N=384) read 1 of 16 hypothetical situations that varied in speaker power and closeness of the speaker‐hearer relationship. Students then read 1 of 48 advice messages representing different politeness strategies and rated the message for regard shown for face and for effectiveness. However, neither speaker‐hearer relationship nor politeness strategies was consistently associated with perceived threat to face or perceived advice effectiveness. We suggest revisions to politeness theory and additional factors that may affect judgments of face sensitivity and advice effectiveness.     

Attentional capture by irrelevant emotional distractor faces is contingent on implicit attentional settings

Although expressions of facial emotion hold a special status in attention relative to other complex objects, whether they summon our attention automatically and against our intentions remains a debated issue. Studies supporting the strong view that attentional capture by facial expressions of emotion is entirely automatic reported that a unique (singleton) emotional face distractor interfered with search for a target that was also unique on a different dimension. Participants could therefore search for the odd-one out face to locate the target and attentional capture by irrelevant emotional faces might be contingent on the adoption of an implicit set for singletons. Here, confirming this hypothesis, an irrelevant emotional face captured attention when the target was the unique face with a discrepant orientation, both when this orientation was unpredictable and when it remained constant. By contrast, no such capture was observed when the target could not be found by monitoring displays for a discrepant face and participants had to search for a face with a specific orientation. Our findings show that attentional capture by emotional faces is not purely stimulus driven and thereby resolve the apparent inconsistency that prevails in the literature on the automaticity of attentional capture by emotional faces.     

Responses to olfactory stimuli in spotted hyenas (Crocuta crocuta): I. Investigation of environmental odors and the function of rolling

Olfaction is crucial to spotted hyenas (Crocuta crocuta), yet there are no controlled studies of their reactions to odors. In Experiment 1, the authors examined responses of captive hyenas to various environmental (prey, nonprey animal, and plant) odors. Subjects approached and sniffed all odors equally but preferentially licked prey odors, scent marked next to odors, and rolled in animal-based odors. In Experiment 2, the authors examined the function of rolling by applying odors to the pelts of captive hyenas. When hyenas wore carrion, they gained positive social attention (increased investigation and allogrooming) from pen mates, but when they wore camphor, the normal social greeting ceremony was curtailed. Thus, olfactory stimuli elicit specific responses, influence where behavior is directed, and can be used to affect social interaction.     

交多少朋友合适?谈亚里士多德对"大量交友"的评论

引言 结交多少个朋友合适?提出这样的问题似乎是钻牛角尖,也不属于哲学家的兴趣.然而,古代的哲学家并未忽视这个问题的重要性,他们都直接或间接地关注过"友谊".实际上,提出交多少朋友合适的问题,就是提出友谊的限度问题,更确切地说,是提出了与他人特殊关系的延展问题.我们看到,这种关系并不要求排他性,但将其无限扩展则难免使其变质.     

Gender differences in combat-related stressors and their association with postdeployment mental health in a nationally representative sample of U.S. OEF/OIF veterans

Though the broader literature suggests that women may be more vulnerable to the effects of trauma exposure, most available studies on combat trauma have relied on samples in which women's combat exposure is limited and analyses that do not directly address gender differences in associations between combat exposure and postdeployment mental health. Female service members' increased exposure to combat in Afghanistan and Iraq provides a unique opportunity to evaluate gender differences in different dimensions of combat-related stress and associated consequence for postdeployment mental health. The current study addressed these research questions in a representative sample of female and male U.S. veterans who had returned from deployment to Afghanistan or Iraq within the previous year. As expected, women reported slightly less exposure than men to most combat-related stressors, but higher exposure to other stressors (i.e., prior life stress, deployment sexual harassment). No gender differences were observed in reports of perceived threat in the war zone. Though it was hypothesized that combat-related stressors would demonstrate stronger negative associations with postdeployment mental health for women, only one of 16 stressor × gender interactions achieved statistical significance and an evaluation of the clinical significance of these interactions revealed that effects were trivial. Results suggest that female Operation Enduring Freedom/Operation Iraqi Freedom service members may be as resilient to combat-related stress as men. Future research is needed to evaluate gender differences in the longer-term effects of combat exposure.