进化的女性生理周期:波动的繁衍动机和行为表现

进化心理学认为女性会随生理周期的变化发生心理和行为的波动,这是由于短暂受孕机会造成的繁衍动机的波动。排卵带来的受孕机会使得女性产生更加强烈的性欲,追求、吸引配偶。为了确保子女基因的优良,女性在排卵期偏好具备优良基因特质的男性,同时采取自我保护行为以避免遗传基因被玷污。此外,女性排卵期的特征还会影响到男性的动机和行为。未来研究应进一步探索排卵期对女性同性间竞争等其他动机的影响,以及消费行为等方面的研究,以拓展实践启示。     

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。     

投资决策进化心理学的研究：预期的私人资金分配和父母对子女的差异性精力投入

投资决策的进化心理学研究着眼于辨认人类获得进化适应的特定环境中经常出现的典型性风险,探寻为了应对这些风险而进化出的信息处理机制,并验证现时的社会因素和个体因素对这些心理机制的激活或抑制作用。在研究一中,被试预测了与自己同龄的男人或女人如何分配一笔中彩的奖金给自己和其他可能的受益人。研究发现：（1）钱数的分配大体由亲缘关系的疏密程度决定;（2）两性被试都假想男性比女性更慷慨,但实际上男性表现得更自利;（3）女性被试预测男性中奖人的金钱分配比男性被试预测女性中奖人的金钱分配更为准确;（4）女性被试的受益人更多,分享的社会范围更广。研究二探讨了父母对子女投入精力的不同取决于家庭的相对财富而非绝对财富的进化心理学假说。用哺乳与否和生育间隔期为测量指标,研究结果显示：（1）家庭实际收入影响父母对子女的总投入;（2）与邻里家庭相比,父母对于自己家庭相对收入的认知影响了对子女有别的差异性精力投入。基于男性普遍在财富和生育数量上比女性有更大的变异度,投资儿子比投资女儿更具博弈性。两项研究表明,人类的理性决策既受限于社会关系又适应于相对的财富状况     

女性生理周期与修饰行为的关系

众所周知, 与男性相比, 女性偏爱修饰。通过修饰行为, 提升自身吸引力具有普遍的社会意义。近年来, 一些研究者将女性修饰行为与繁殖目的联系起来, 认为女性修饰行为受到生理周期(主要是排卵期和安全期)的影响。具体而言, 排卵期时, 女性的修饰行为会增强, 缘于同性竞争, 包括竞争资源及配偶; 黄体期时, 启动异性吸引动机也会显著增强女性的修饰动机, 目的可能是保持“异性”对自己及后代的持续“投资”。总之, 上述观点为女性持续存在的、对修饰行为的关注提供了生物学解释。     

男性监控配偶、配偶不贞与精子竞争的关系

精子竞争是指同一女性产道中两个或两个以上男人的精子相互竞争卵子的过程。女性得到社会承认的性伙伴可能因精子竞争失败而损失惨重,因为女性私通可能引起男性投资于不携带自己基因的后代。过去研究表明进化而来的男性配偶监控策略可以防止女性不贞,减少精子竞争失败的危险。当前研究发现男性与配偶进行性行为后离别时间越久,男性就越采取出其不意地打电话、独占配偶时间、威胁对配偶感兴趣的男性等手段来监控配偶     

女为悦己者容:择偶动机对女性身体(自我)客体化的影响

以往研究大多从社会文化的角度解释对女性身体的客体化。本研究提出,两性对女性身体的客体化以及女性的自我客体化可能是对性选择的一种适应机制。通过启动择偶动机,本研究发现,性选择情境会引发两性对于女性(而非男性)身体的客体化和自我客体化,将女性身体知觉为“物”而非“人”,更看重其身体的外形吸引力而非能力。研究揭示了择偶动机影响女性身体客体化的心理机制,为性选择对女性身体客体化的进化塑造作用提供了初步实证支持。     

未来配偶偏爱的特征——选择长期配偶与短期配偶的条件

该研究中被试分配有限“配偶币”来抉择与理想配偶标准相符合的性交往对象。首先,该研究重复验证了Li 等人 (2002) 和Kenrick (2006)的发现,男性理想的长期配偶需要外表出众,而女性理想的长期配偶需要社会地位较高;两性理想的短期配偶都必须外表出众。其次,两性所投射出的理想自我与潜在配偶偏好的特征一致,研究发现,长期性交往条件下,男性需要具有较高社会地位,女性需要外表出众;短期性交往条件下,男性和女性都需要外表出众。评价潜在配偶的机制与评价现有配偶的机制可能是两种受到选择的不同的心理机制。     

资源多寡对大学生择偶线索偏好的影响

本研究采用分配择偶币的范式考察资源多寡对大学生择偶线索偏好的影响。结果发现：1）择偶资源多寡影响大学生的择偶线索偏好,低资源条件下人们更看重忠贞、健康等“必需品”（necessities）,高资源条件下则会增加对创造力等“奢侈品”（luxuries）的考虑。2）择偶线索偏好存在性别差异,当自身资源较少时,女性比男性更看重长期伴侣的社会经济地位,而男性比女性更看重伴侣的忠贞;当自身具备高资源时,性别差异不显著。本研究发现择偶线索中的“奢侈品”和国外研究结果类似,而“必需品”和国外研究差异较大。研究结果表明,择偶线索偏好可能受到进化和社会文化因素的共同影响。     

数学成就的性别差异

数学成就的性别差异是多年来广受关注的问题。长期以来人们多关注男性、女性数学成就水平的高低, 而近年来研究结果一方面揭示出总体上男性和女性数学成就的平均水平差异很小, 呈现出相似性多于差异性的特点; 同时也显示男性内部变异比女性更大, 男性在高数学成就者中占多数。数学成就性别差异的大小和方向受到评分系统、测验组织形式、测验内容和难度的影响。数学成就性别差异的形成是心理、生物、社会文化等方面多因素综合作用的结果。近期研究探讨了年龄、遗传和进化、激素和脑、刻板印象威胁、社会性别公平和时代等因素在数学成就性别差异的形成中的作用。未来对数学成就性别差异的研究应注意开展追踪研究, 关注低数学能力者, 进一步探讨复杂数学加工机制的性别差异, 建立数学成就性别差异形成机制的综合模型, 并在更广阔的社会文化背景下开展研究。     

语言——自然选择的一种适应

该文认为人类的语言能力是一种生物学意义上的适应,是自然选择的产物。人类的语言与自然界中其它复杂的生物学适应相类似,也具有特定的机能。语言的特定机能在于编码叙事性信息并与他人分享,这与人类认知活动中因果推理所具有的高度社会性特点相一致。两个新的研究领域,进化博弈理论和分子进化选择理论,都证实了语言是一种受到自然选择的进化适应     

Physical cues of ovulatory status: A failure to replicate enhanced facial attractiveness and reduced waist-to-hip ratio at high fertility

We investigated women's facial attractiveness and body shape as a function of menstrual cycle phase, with the expectation from previous research that both would be enhanced during the high fertile phase. To control for the effects of women's daily behaviors on their appearance and waistline, we visited 37 normally cycling women twice in their dorm, where we photographed and measured them at low and high fertile days of their cycle immediately upon their waking. Seventy-four judges from a separate institution chose, for each woman, the picture they thought was more attractive. We analyzed a subset of 20 women who, by forward counting, had a High Fertility visit between Days 10-13 and a Low Fertility visit between Days 20-23; and we also analyzed a subsample of 17 women who, by reverse counting, had a High Fertility visit on the days leading to ovulation and a Low Fertility visit one week after ovulation. In neither set of analyses were women's waist- to-hip ratios lower nearer ovulation, and in neither set were women's high fertile pictures chosen at an above-chance rate by either male or female judges. We did not find evidence that facial attractiveness and waist-to-hip ratio are reliable physical cues of ovulatory status.     

Mating interest improves women's accuracy in judging male sexual orientation

People can accurately infer others' traits and group memberships across several domains. We examined heterosexual women's accuracy in judging male sexual orientation across the fertility cycle (Study 1) and found that women's accuracy was significantly greater the nearer they were to peak ovulation. In contrast, women's accuracy was not related to their fertility when they judged the sexual orientations of other women (Study 2). Increased sexual interest brought about by the increased likelihood of conception near ovulation may therefore influence women's sensitivity to male sexual orientation. To test this hypothesis, we manipulated women's interest in mating using an unobtrusive priming task (Study 3). Women primed with romantic thoughts showed significantly greater accuracy in their categorizations of male sexual orientation (but not female sexual orientation) compared with women who were not primed. The accuracy of judgments of male sexual orientation therefore appears to be influenced by both natural variations in female perceivers' fertility and experimentally manipulated cognitive frames.     

Evidence for menstrual cycle shifts in women's preferences for masculinity

Over the last decade, a growing literature has shown that women in the fertile phase of the menstrual cycle demonstrate stronger preferences for men with masculine traits than they do when in the non-fertile phases of the cycle (see Gangestad and Thornhill, 2008 and Jones et al., 2008 for recent reviews). In a recent article, Harris (in press; Sex Roles) failed to replicate this increase in women's preferences for masculine faces when women are near ovulation. Harris represented her study as one of only three studies on the topic, and as the largest of the existing studies. There are, however, many more studies on menstrual cycle shifts in preferences for facial masculinity in the published literature, including one that is 2.5 times larger in size than the Harris study. In this article, we review the evidence for cyclic shifts in mate preferences and related behaviors and discuss weaknesses of Harris's methods. Considered as a whole, the evidence for menstrual cycle shifts in women's preferences and behaviors is compelling, despite the failure of replication reported by Harris.     

Women's preferences for male behavioral displays change across the menstrual cycle

Abstract— Women prefer both the scent of symmetrical men and masculine male faces more during the fertile (late follicular and ovulatory) phases of their menstrual cycles than during their infertile (e.g., luteal) phases. Men's behavioral displays in social settings may convey signals that affect women's attraction to men even more strongly. This study examined shifts in women's preferences for these behavioral displays. A sample of 237 normally ovulating women viewed 36 or 40 videotaped men who were competing for a potential lunch date and then rated each man's attractiveness as a short-term and a long-term mate. As predicted, women's preference for men who displayed social presence and direct intrasexual competitiveness increased on high-fertility days relative to low-fertility days, but only in a short-term, not a long-term, mating context. These findings add to the growing literature indicating that women's mate preferences systematically vary across the reproductive cycle.     

The ‘Chasing Amy’ Bias in Past Sexual Experiences: Men Can Change,Women Cannot

An extensive sexual history may deter individuals from committing to a potential romantic partner. However, the reasons for this deterrence may differ between men and women, such that women focus on practical concerns over suitability whereas men focus on reputation. Thus, individuals with extensive sexual histories, who are currently monogamous, should be more acceptable to women than they are to men. Two studies supported this hypothesis. Study 1 found that women rated male targets with a sexually experienced past with increased desirability for a long-term relationship if they reported recent shifts towards monogamy. In contrast, men rated sexually experienced female targets, with a recent shift towards monogamy, as least desirable. Study 2 extended the understanding of this effect by demonstrating that one time sexual experiences (i.e., threesome) had no effect on women’s judgments of currently monogamous men, but continued to negatively affect men’s judgments of currently monogamous women. In sum, women seem accepting of lifestyle changes in men, whereas men fixate on women’s previous experiences in spite of shifts towards monogamy.     

Perceptual mechanisms that characterize gender differences in decoding women's sexual intent

Men and women often disagree about the meaning of women's nonverbal cues, particularly those conveying dating-relevant information. Men perceive more sexual intent in women's behavior than women perceive or report intending to convey. Although this finding has been attributed to gender differences in the threshold for labeling ambiguous cues as sexual in nature, little research has been conducted to determine etiology. Using a model that differentiates perceptual sensitivity from decisional bias, we found no evidence that men have lenient thresholds for perceiving women's nonverbal behavior as indicating sexual interest. Rather, gender differences were captured by a relative perceptual insensitivity among men. Just as in previous studies, men were more likely than women to misperceive friendliness as sexual interest, but they also were quite likely to misperceive sexual interest as friendliness. The results point to the promise of computational models of perception in increasing the understanding of clinically relevant social processes.     

The sexual overperception bias is associated with sociosexuality

As reproductive rates have the potential to be higher in men than women, it is more costly (from an evolutionary perspective) for men to miss a mating opportunity than women. This asymmetry in costs has been proposed to result in men being more sensitive to cues to sexual opportunity than women, and thus men are more likely than women to misperceive sexual interest from opposite sex others. To investigate this sexual misperception bias, smiling male and female faces were presented to participants who were asked to judge whether the face appeared friendly or flirtatious. Participants also completed a sociosexual orientation questionnaire in order to assess their current attitudes towards sexual relationships. In general, we found that males perceive female faces as flirtatious significantly more often than females. However, our results also suggested that people with high scores on the sociosexuality inventory (who rated themselves as more likely to engage in short-term, casual relationships), regardless of sex, had a tendency to perceive the faces of potential mates as more flirtatious, and that this variable explained more variance than sex alone. Our findings demonstrate that sociosexuality may mediate biases in perceiving the sexual intent of others.     

Women seek more variety in rewards when closer to ovulation

We propose that women's increased generalized sensitivity to rewards during the fertile phase of the menstrual cycle causes them to seek more variety in rewards when they are in the fertile phase than when they are not in the fertile phase of the cycle. In Studies 1–3, across the reward domains of mating and hedonic food, we show that women seek more variety in rewards when closer to ovulation. Moreover, we provide support for the proposition that women's increased reward sensitivity during the fertile phase of the menstrual cycle causes their greater variety seeking. Specifically, in Study 3, we show that fertile women's greater variety seeking does not extend to non-rewards, such as non-hedonic food. Our findings suggest that behavioral effects of women's hormonal shifts during the menstrual cycle are not limited to the mating domain and may extend to a wide category of reward domains.     

Adaptations to Ovulation

ABSTRACT— In socially monogamous species in which males heavily invest in offspring, there arises an inevitable genetic conflict between partners over whether investing males become biological fathers of their partners' offspring. Humans are such a species. The ovulatory-shift hypothesis proposes that changes in women's mate preferences and sexual interests across the cycle are footprints of this conflict. When fertile (mid-cycle), women find masculine bodily and behavioral features particularly sexy and report increased attraction to men other than current partners. Men are more vigilant of partners when the latter are fertile, which may reflect evolved counteradaptations. This adaptationist hypothesis has already generated several fruitful research programs, but many questions remain.     

Major histocompatibility complex alleles, sexual responsivity, and unfaithfulness in romantic couples

Preferences for mates that possess genes dissimilar to one's own at the major histocompatibility complex (MHC), a polymorphic group of loci associated with the immune system, have been found in mice, birds, fish, and humans. These preferences may help individuals choose genetically compatible mates and may adaptively function to prevent inbreeding or to increase heterozygosity and thereby immunocompetence of offspring. MHC-dissimilar mate preferences may influence the psychology of sexual attraction. We investigated whether MHC similarity among romantically involved couples (N= 48) predicted aspects of their sexual relationship. All women in our sample normally ovulated, and alleles at three MHC loci were typed for each person. As the proportion of MHC alleles couples shared increased, women's sexual responsivity to their partners decreased, their number of extrapair sexual partners increased, and their attraction to men other than their primary partners increased, particularly during the fertile phase of their cycles.