Dynamics of Religious Group Growth and Survival

We model and analyze the dynamics of religious group membership and size. A group is distinguished by its strictness, which determines how much time group members are expected to spend contributing to the group. Individuals differ in their rate of return for time spent outside of their religious group. We construct a utility function that individuals attempt to maximize, then find a Nash equilibrium for religious group participation with a heterogeneous population. We then model dynamics of group size by including birth, death, and switching of individuals between groups. Group switching depends on the strictness preferences of individuals and their probability of encountering members of other groups. We show that in the case of only two groups—one with finite strictness and the other with zero—there is a parameter combination that determines whether the nonzero strictness group can survive over time, which is more difficult at higher strictness levels. We also show that a high birth rate can allow even the strictest groups to survive. Finally, we consider cases of several groups, gaining insight into strategic choices of strictness values and displaying the rich behavior of the model.     

Emergent Processes in Group Behavior

ABSTRACT— Just as neurons interconnect in networks that create structured thoughts beyond the ken of any individual neuron, so people spontaneously organize themselves into groups to create emergent organizations that no individual may intend, comprehend, or even perceive. Recent technological advances have provided us with unprecedented opportunities for conducting controlled laboratory experiments on human collective behavior. We describe two experimental paradigms in which we attempt to build predictive bridges between the beliefs, goals, and cognitive capacities of individuals and patterns of behavior at the group level, showing how the members of a group dynamically allocate themselves to resources and how innovations diffuse through a social network. Agent-based computational models have provided useful explanatory and predictive accounts. Together, the models and experiments point to tradeoffs between exploration and exploitation—that is, compromises between individuals using their own innovations and using innovations obtained from their peers—and the emergence of group-level organizations such as population waves, bandwagon effects, and spontaneous specialization.     

From steroids to nation states: An integrated evolutionary approach to violent crime

Most evolutionary psychologists emphasize the individual level of analysis concerning violent crime and other dependent variables. This paper outlines a strategy for evolutionary explanation of societal variation across time as well as space and applies it to crimes of violence. The central idea is that individual adaptations for reproductive competition play out differently depending both on developmental context and societal conditions, including the marriage market. Violent crimes (murders, rapes, and assaults) are substantially higher in countries with a relative scarcity of men according to research using INTERPOL and World Health Organization data [Barber, N. (2000a). The sex ratio as a predictor of cross-national variation in violent crime. Cross-Cultural Research, 34, 264–282, Barber, N. (2009). Countries with fewer males have more violent crime: Marriage markets and mating aggression. Aggressive Behavior, 35, 49–56]. This is an apparent contradiction given that males are more criminally violent and likely reflects increased direct mating competition that evokes increased testosterone production for humans as for other species. The empirical evidence is discussed in terms of direct reproductive competition and various alternative explanations, particularly the “culture of violence” and socialization experiences are considered.     

The Influence of Abnormal Sex Differences in Life Expectancy on National Happiness

Countries with better health, as indexed by life expectancy, score higher on subjective well-being (SWB). It was predicted that deviations from the average sex difference in life expectancy (reflecting reproductive competition among males and discrimination against females) would be inversely related to happiness. Regression analysis of SWB for 178 countries found that deviations from the average sex difference in life expectancy were predictive of unhappiness controlling for life expectancy, national wealth, and income inequality. Countries with a relative scarcity of female children (used as an index of parental bias) were less happy. Societies in which there is an undue burden on the health and survival of either sex are thus unhappy ones due to gender-specific disadvantage and associated gender conflict.     

Harnessing the wandering mind: The role of perceptual load

Perceptual load is a key determinant of distraction by task-irrelevant stimuli (e.g., Lavie, N. (2005). Distracted and confused?: Selective attention under load. Trends in Cognitive Sciences, 9, 75-82). Here we establish the role of perceptual load in determining an internal form of distraction by task-unrelated thoughts (TUTs or “mind-wandering”).Four experiments demonstrated reduced frequency of TUTs with high compared to low perceptual load in a visual-search task. Alternative accounts in terms of increased demands on responses, verbal working memory or motivation were ruled out and clear effects of load were found for unintentional TUTs. Individual differences in load effects on internal (TUTs) and external (response-competition) distractors were correlated. These results suggest that exhausting attentional capacity in task-relevant processing under high perceptual load can reduce processing of task-irrelevant information from external and internal sources alike.     

人类精子库伦理管理的困惑与对策

建立人类精子库主要用于解决不孕不育问题,在一定程度上解决了男性不育的难题,拓展了生殖医学及发育生物学领域,为许多不孕不育夫妇带来了福音,具有广泛的科学及社会学意义。但是,冷冻精子的使用所涉及的医学、人文、法律、伦理、道德等问题已成为严肃的值得深思熟虑的社会问题。如不加以规范和管理,必将对人类及整个社会造成危害。     

急性应激对工作记忆的影响受工作记忆负荷调节:来自电生理的证据

急性应激如何影响工作记忆还不清楚。采用电影片断诱发被试的急性应激或中性状态后,让其完成数字N-back任务并同时记录脑电。结果发现,低负荷工作记忆诱发的P3显著大于高负荷工作记忆;在0-back任务中,急性应激组诱发的P3显著大于控制组;而在2-back任务中,这种差异不显著。这些结果表明急性应激对工作记忆的影响受工作记忆负荷调节,支持了双竞争理论模型。     

Dominance structure in small groups of juvenile white-seabream (Diplodus sargus cadenati de la paz,Bauchot and Daget 1974)

Experiments were conducted to investigate the intraspecific aggressive interactions between juveniles of white-seabream (Diplodus sargus cadenati de la Paz, Bauchot and Daget 1974) in relation to dominance hierarchy in small groups. The agonistic interactions between juvenile white-seabream in small groups originated a peck-dominance hierarchy. The dominant (α-fish) generally interacted aggressively and most frequently with the subordinate that was next in line (β-fish) within the dominance hierarchy. This β-fish interacted aggressively more frequently with the γ-fish, and so on. Results demonstrated that fish do not attack subordinates at random. The level of subordination in small groups of juvenile white-seabream was related to body size. Generally, the more aggressive fish manifest a higher growth rate. Aggr. Behav. 24: 197–204, 1998. © 1998 Wiley-Liss, Inc.     

基于工作记忆内容的视觉注意

视觉系统是一个资源有限的信息加工系统, 在任何时刻视觉注意只能选择外界环境中的有限信息进行加工。工作记忆对于解决视觉场景中不同物体之间的注意竞争具有重要作用, 保持在工作记忆中的物体表征会以自上而下的方式引导注意优先选择视场中与之匹配的物体。本文系统回顾了有关工作记忆内容对视觉注意的引导作用的研究文献, 并探讨了基于工作记忆内容的视觉注意捕获的自动性, 指出基于工作记忆内容的视觉注意捕获是一个有条件的自动化过程。     

Testosterone and attribution of successful competition

Mood, personal merit, and/or its perception have been suggested to be mediating factors in testosterone responses to competition. Previously we have found that personal contribution and attribution were related to testosterone levels after successful competition. To confirm such associations, two basketball teams (n = 17 players) that emerged as winners in two actual matches were studied. Salivary testosterone levels and mood were measured before and after the games. Individual contribution to the outcome was assessed, and personal satisfaction and causal attribution of outcome were reported by players. Testosterone concentrations increased to near significance in Team 1 but not in Team 2, who attributed their victory more to luck than did Team 1. This latter team showed notably decreased vigor, and both teams showed fatigue at the end of the match. Post‐match testosterone levels were only significantly, negatively related to external attribution. The results support the idea that causal attribution of the outcome is contributing to the variance of the testosterone responses to real confrontations where the outcome is highly dependent on personal merit. Aggr. Behav. 26:235–240, 2000. © 2000 Wiley‐Liss, Inc.