Body size as a determinant of aggression during heterosexual encounters in hormone-treated gonadectomized pigs

Aggressive and sexual behavior was studied in 5-minute paired encounters between testosterone-treated castrated boars and estrogen-treated ovariectomized gilts. The boars were either 15 kg heavier (N = 6), or lighter (N = 6), than the gilts (N = 8). Tests were carried out over a 4-week period, during which time each boar was paired once with each gilt; the procedure was replicated over a further 4 weeks. Gilts usually initiated the aggression, especially in the first 4-week period; however, the degree of aggression was positively correlated with body size, irrespective of sex. Aggression was reduced in the second 4-week period in both sexes in tests with large, but not with small, boars. Large boars were more sexually active than small boars, and their sexual performance improved markedly with time, unlike that of the small boars. Champing was positively correlated with aggression duration in pigs of both sexes, and salivation was seen more often in boars than gilts.     

Aggression during sexual encounters between hormone-treated gonadectomized pigs in the presence or absence of boar pheromones

Aggressive and sexual behaviour was studied in 5-min paired encounters between castrated prepubertal boars (N = 14) and normal (N = 2) or bulbectomized (N = 2) oestrogen-treated ovariectomized gilts. The boars were made sexually active by treatment with 17β-oestradiol + 5α-dihydrotestosterone. Half of the boars were sprayed on the snout with a solution containing a mixture of the boar pheromones 3α-androstenol and 5α-androstenone immediately before testing, and the remainder were treated with the vehicle solution. Aggression was almost always initiated by the gilts, and neither bulbectomy nor pheromone treatment of the boars reduced its occurrence. The results suggest that the display of aggression by gilts towards boars of similar body size is unlikely to be suppressed by the steroidal pheromones present in boar saliva.     

Creative Activity,Personality, Mental Illness,and Short‐Term Mating Success

It has been argued that creativity evolved, at least in part, through sexual selection to attract mates. Recent research lends support to this view and has also demonstrated a link between certain dimensions of schizotypy, creativity, and short‐term mating. The current study delves deeper into these relationships by focusing on engagement in creative activity and employing an expansive set of personality and mental health measures (Five Factor Model, schizotypy, anxiety, and depression). A general tendency to engage in everyday forms of creative activity was related to number of sexual partners within the past year in males only. Furthermore, schizotypy, anxiety, and Neuroticism were all indirectly related to short‐term mating success, again for males only. The study provides additional support for predictions made by sexual selection theory that men have a higher drive for creative display, and that creativity is linked with higher short‐term mating success. The study also provides support for the contention that certain forms of mental illness may still exist in the gene pool because particular personality traits associated with milder forms of mental illness (i.e., Neuroticism & schizotypy) are also associated directly with creativity and indirectly with short‐term mating success.     

Agonistic and sociable behaviors in the mound‐building mice,Mus spicilegus: A comparative study with Mus musculus domesticus

Present social organization and mating systems result from selective pressures and ecological conditions but also from proximate interactions between individuals. Many studies report on a polygynous mating system with a social group territoriality in commensal populations of Mus musculus domesticus. However, little is known about the social organization of other Mus species living in outdoor conditions, such as the mound‐building mouse Mus spicilegus. Comparative studies between M. m. domesticus and M. spicilegus have already shown behavioral differences in female sexual preferences and paternal care. To study agonistic and sociable interactions and gain insight into the social organization and the mating system of M. spicilegus, the present study compared intraspecific dyadic encounters between unfamiliar adults in these two species. Results demonstrated less tolerance between females and between the sexes in M. spicilegus than in M. m. domesticus unfamiliar mice. The consequences of those differences between M. spicilegus and M. m. domesticus on social organization and mating system are discussed. Aggr. Behav. 28:75–84, 2002. © 2002 Wiley‐Liss, Inc.     

求偶动机对男性冒险行为倾向的影响

基于风险行为的性选择理论, 通过内隐启动的方法探讨了求偶线索与奖赏线索对两性风险行为报告的影响。研究结果显示, 男性接触求偶线索, 与接触奖赏线索相比, 更有可能进行娱乐领域、健康领域与社会领域的风险行为活动; 而女性接触奖赏线索后, 与求偶线索相比, 更有可能会从事社会领域的风险行为活动; 两性接触求偶线索与奖赏线索后都较少可能从事经济领域的风险行为活动。这些结果符合性选择理论, 说明与求偶有关的信息线索能够诱导男性进行高风险活动, 因为在进化过程中冒险行为可以作为好基因的标志增加男性获得配偶的机会。这些结果还揭示了, 求偶动机对男性冒险行为的诱发作用远胜于外部动机(如金钱奖赏), 因为求偶是人类在长期进化过程中形成的本能需求。     

从进化心理学视角看两性冒险行为

进化心理学研究发现, 男性比女性更冒险, 男性冒险行为有社会助长和性别助长效应, 求偶动机与异性高魅力均可助长男性冒险行为。按照进化心理学观点, 冒险行为能表现男性作为潜在配偶的积极特征, 可增加其获得异性配偶的几率。择偶偏好研究也证实, 女性青睐敢于冒险的男性。作者认为, 女性冒险行为与求偶动机的关系主要受社会文化影响, 如中国女性在中意的异性面前更避险, 冒险行为领域中进化和文化的交互作用可能成为未来研究焦点。     

婚恋关系中的相似性匹配及争议

婚恋匹配涉及身体特征、社会人口统计学特征、个性心理等方面,有相似性匹配和互补性匹配两种假说,但相似匹配的证据远多于互补。针对感知相似与实际相似的作用、相似性匹配与婚恋质量的关系、以及相似匹配的优势地位与适宜性等争议,分析了导致相似性匹配争议的原因。未来应致力于深化研究内容以建立婚恋匹配理论模型,实现测评方法的多样化、测量指标和工具的科学化,确保相似性计算和统计分析方法的严谨性,并加强婚恋匹配的本土化和跨文化研究。     

繁衍线索对风险信息加工的影响

进化理论认为风险行为与求偶有关。研究通过比较求偶信息(异性照片或描述异性的词语)、养育后代(孕妇照片)及奖赏信息(金牌照片等)试图进一步探讨繁衍线索对两性知觉和判断风险信息的影响。研究1中, 被试描述理想约会对象后求偶动机得到激发, 相对于描述晴朗天气的控制组, 求偶动机让两性更慢地从高风险信息(如滑雪、冲浪等)转移注意力, 且两性对风险信息的注意转移与社群性向无关。研究2显示, 相对于养育后代和奖赏信息, 求偶信息更为迅速地促使男性对高风险信息做出判断, 但求偶信息让女性比男性更慢地对高风险信息做出判断。研究结果进一步证实了自然选择理论及性选择理论对两性加工风险信息的认知机制具有预测作用。     

Why is violent crime so common in the Americas?

Violent crimes, including murders, rapes, and assaults are substantially higher in the Americas than other regions of the world. This study investigated the role of single parenthood ratios in accounting for this regional variation in violent crime of 39 countries using INTERPOL data. It pitted the prediction of parental investment (calling for a delayed relationship between single parenthood and crime) against a mating aggression hypothesis that predicted a contemporaneous effect. Regression analyses found that current single parenthood ratios were strongly and consistently predictive of violent crimes whereas single parenthood ratios 18 years earlier were not and this conclusion remained following controls for income inequality and the population sex ratio. The results indicate that the regional difference in violent crime is best explained in terms of mating competition rather than reduced parental investment. Aggr. Behav. 32:1–9, 2006. © 2006 Wiley‐Liss, Inc.     

人类“性交往”的进化

性交往是人类繁衍出现差异的进化“引擎”。现代人继承了祖先成功繁衍后代的性交往策略。这些策略涵盖长期守诺的性交往（如婚姻）、短期性交往（如短暂的外遇）、婚姻外的性交往（如不忠）、私通他人配偶（引诱别人的配偶）以及配偶维持（与单一配偶性交往）等。两性在性交往过程中面临不同的适应问题,性交往问题的进化机制存在极大的性别差异。配偶偏好不同、短期性交往的愿望不同以及性嫉妒的诱因不同等都是性交往具有性别差异的表现。很多实证研究都证实了性交往策略的存在,人类性交往研究是进化心理学研究中较为成熟的一个研究领域