Evolutionary Psychology: Long-Term Sexual Strategies PDF

PSYC205 Evolutionary Psychology Long-Term Sexual Strategies Edison Tan Evolutionary Psychology Singapore Management University  Sexual Selection Intra-sexual Inter-sexual Comp...

PSYC205 Evolutionary Psychology Long-Term Sexual Strategies Edison Tan Evolutionary Psychology Singapore Management University  Sexual Selection Intra-sexual Inter-sexual Competition Competition Competition between members of the same Manifest as preferential mate choices sex. Individuals who display superior Individuals of the opposite sex with characteristics during intrasexual advantageous characteristics are preferred competition gain sexual access to mates as mates. directly or indirectly (e.g., controlling e.g., ability and willingness to offer territory or resources). gifts of food and other resources to desired mates Superior attributes that are inheritable are Individuals who do not possess passed down to offspring, conferring advantageous characteristics are less likely offspring with intrasexual competitive to be chosen as mates, reducing advantages. reproductive odds. Edison Tan Evolutionary Psychology Singapore Management University Why do women bear more reproductive costs? Female Male Parental Investment Theory & Sexual Selection Theory Gametes are limited and Gametes are The sex that invests more in offspring (typically, but not always, replenishable, only a replenishable the female) will be more discriminating or selective about few hundred will be mating. ovulated The sex that invests less in offspring will be more competitive 9 months of pregnancy Energy spent during for sexual access to the high-investing sex. sexual intercourse No biological law dictates that females must invest more than males; Up to 4 year of males invest more in some organisms. lactation Sex-role typically reversed in those species Time-spent nurturing child Childbearing and childbearing ability are invaluable reproductive resources. Those who bear those resources do not give them away to Risk-taken whilst just about anyone. protecting the offspring Edison Tan Evolutionary Psychology Singapore Management University Mate Preference as Evolved Psychological Mechanism Decision Algorithm Input: Output: e.g., Gift of food from IF → THEN Mate with the generous IF (man generous) man man THEN (mate with man) Mate preferences evolved to address adaptive problems associated with reproduction. For example: Men who sacrifice their time and energy to provide for a woman and offspring, offsetting the cost of parenting, enhance her reproductive success Beautiful woman who probably possesses healthier genes and is more fertile, potentially producing more offspring with better survival odds, enhancing his reproductive success Traits, tendencies, and characteristics that promote fitness are preferred, those that impose cost are avoided Men who are productive, kind, and influential vs. men who are lazy, unempathetic, a social pariah Women who are youthful, with many years of fertility vs. older women with limited fertility Edison Tan Evolutionary Psychology Singapore Management University  01 Women’s Long-Term Mate Preference Edison Tan Evolutionary Psychology Singapore Management University Adaptive Problems Faced by Women Adaptive Problems Evolved Preference Selecting a mate who is able to Good financial prospect Social Status invest Slightly older age Ambition/industriousness Size, strength, and athletic ability Selecting a mate who is willing to Dependability and stability Display of love and commitment invest Positive interaction with children Interrelated Selecting a mate who is able to Height Bravery physically protect her and children Athletic Ability Masculine body Selective a mate who will show good Dependability Emotional stability parenting skills Kindness Positive interaction with children Selecting a mate who is compatible Similarity Selecting a mate who is healthy Physical Attractiveness Symmetry Health Masculine features Edison Tan Evolutionary Psychology Singapore Management University  Selecting a mate who is able to invest Numerous cross-cultural studies using different methodologies If not current, future resource is preferred – preference for and vastly different samples have consistently suggested that characteristics indicative of resource-acquiring ability. women prioritize men’s financial might in their mate preference. Intelligence and creativity Ambition and Industriousness Size, strength, and athletic ability Social status Humans lived in groups with clearly defined social hierarchy; resources typically trickle from to bottom, with those of higher social status having the most control Somewhat older men Older men have more time to build alliances, skills, and mastery of the environment Wealth and status tend to correlate positively with age for men Edison Tan Evolutionary Psychology Singapore Management University Selecting a mate who is able to invest Edison Tan Evolutionary Psychology Singapore Management University Selecting a mate who is able to invest Edison Tan Evolutionary Psychology Singapore Management University  Selecting a mate who is willing to invest Men typically seek sexual variety and may channel their Dependability and stability are reliable signals that resources resources toward another woman instead. will be provided consistently over time. Expression of love and commitment signals intention to Men also tend to withhold resources during paternal uncertainty. commit all their resources to only one woman and their offspring. Hence, women seek men who signal their willingness to invest Willingness to invest in children by men audition paternal resources in them. qualities Women appear to be able to detect if men like infants, and their perception of whether men like infants positively predicts attractiveness as long-term mates Edison Tan Evolutionary Psychology Singapore Management University  Selecting a mate who is able to physically protect her and children Women sometimes face domination by other larger, stronger males, which leads to injury and sexual domination A strong, physically powerful male with high aesthetic ability signals the ability to offer protection Tall Physical Strength V-shaped torso Broad shoulder relative to hips Edison Tan Evolutionary Psychology Singapore Management University  Selecting a mate who is compatible Successful long-term mating requires sustained cooperative alliances over time. Similarity leads to emotional bonding, cooperation, communication, mating happiness, lower risk of breaking up, and possibly increased offspring survival. Homogamy – Preferences for someone who shares similar values, political orientation, worldviews, and individual differences (e.g., personality and intellect). Reflective of positive assortative mating in humans - the tendency to choose mates more similar to themselves in phenotype characteristics than would be expected by chance. Enhancing offspring survival by improved cooperation and coordination within mated pairs Edison Tan Evolutionary Psychology Singapore Management University  Selecting a mate who is healthy Mating with unhealthy mates imposes costs on women Unhealthy males cannot deliver food, protection, and parental support efficiently. Premature death cuts off resource Potentially carry disease Potentially carry poor genes Preference for symmetrical face and body Signal ability to withstand environmental and genetic stressors Preference for masculine features Testosterone is an immunosuppressant; only healthy males can absorb the “cost of producing a high testosterone level. May also signal dominance and physical prowess. Edison Tan Evolutionary Psychology Singapore Management University  02 Men’s Long-Term Mate Preference Edison Tan Evolutionary Psychology Singapore Management University  Benefits of Commitment for Men With the lower reproductive cost and usually being the sex that controls the allocation of resources, why would men want to commit to a single mate for the long term? Reduced intrasexual competition from men who failed intersexual competition Men who are willing to commit will be seen as more desirable by women Increased quality of mate Women who typically desire lasting commitment are also typically in the best position to ask for commitment Reduced paternal uncertainty through exclusive sexual access Increased survival odds of offspring with prolonged parental investment of both parents or related kins. Increased reproductive success of offspring from paternal investment Increase social status Access to partner’s resources and status Increase lifespan Edison Tan Evolutionary Psychology Singapore Management University Adaptive Problems Faced by Men Adaptive Problems Evolved Preference Selecting a mate who has high reproductive Youth value and fertility Physical Attractiveness Paternal Uncertainty Chastity Sexual Fidelity Selecting a mate who is has good genes Physical Attractiveness Similar to Women’s Selecting a mate who is adept at childrearing Kindness and empathy Selecting a mate who is compatible Similarity Selecting a mate who aid mutual survival Intelligence Cooperative Edison Tan Evolutionary Psychology Singapore Management University Reproductive Values vs Fertility Reproductive value – number of offspring, given the age and sex, an individual is likely to have in the future Fertility – actual reproductive performance measured by the number of viable offspring produced. A 24-year-old woman may be more fertile, but a 17-year-old woman has more reproductive value Edison Tan Evolutionary Psychology Singapore Management University  Beauty Standards Benefits of Preference/Cue Suggestive of Benefits Evolved Long, high quality hair Youth Health Beauty Skin quality (i.e., low blemishes, glow) Absence of parasite Absence of skin-damaging disease Good gene resistant to diseases Standards: General health and vitality Feminine features Youth (i.e., full lips, relatively large eyes, thinner Fertility What is jaws, small chin, high cheekbones, a relatively short distance between mouth and jaw, high pitch voice) Facial symmetry Good gene resistant to diseases Considered Facial averageness Resistant to environmental insults Cognitively less demanding to process Genetic or phenotypic average may indicate Attractive? susceptivity to environmental insults or mutation Long legs (relative to torso length) Health Biomechanical efficiency Lumbar curvature Reduced injury biomechanical challenges during pregnancy A lower waist-to-hip (WTP) ratio than the Reproductive Value local average in modern society, around.70. Edison Tan Evolutionary Psychology Singapore Management University  Mechanism for Detecting Ovulation Human females do not experience estrus – a period during ovulation where females exhibit maximal sexual receptivity, with physiological and anatomic indicators – making successfully detecting fertile women an adaptive problem. Men who possess adaptations to detect ovulation in women possess reproductive advantages. Input cues include: Skin glow around cheeks due to blood saturation Lighter skin color Decreased WHR due to estrogen activity Rise in voice pitch Sexual receptivity and initiative Body odor Edison Tan Evolutionary Psychology Singapore Management University  Paternal Uncertainty As women bear offspring during pregnancy, Evolved preference as adaptive solutions women can be sure that the child they bore is : hers. Males of other species may use cues indicating estrus in a mate to sequester, Chastity prioritize sexual intercourse, and defend their Chastity and sexual permissiveness mate from other males. signal potential future infidelity Signal not directly available to human males Sexual fidelity In humans, men cannot guard their mate Faithfulness, commitment, and loyal around the clock, given other adaptive characteristics are highly desirable to problems. They cannot be sure that the offspring his mate bore is fathered by him – men. Paternal Uncertainty. Women can signal fidelity with mate defensive behaviors Failure to ensure fidelity meant his resources were channeled toward other men’s offspring. Edison Tan Evolutionary Psychology Singapore Management University  03 Context Effects Edison Tan Evolutionary Psychology Singapore Management University Context Effects on Women Mating Strategies Personal Other Attractive Personal mate Resource Women value Women holding more personal Copying is a relatively energy- Women with more attractive qualities resources (i.e., wealth and career efficient means of generating adaptive are highly desirable to men; they prospects) place even more emphasis solutions. Information from others have more options and are choosier. on good financial prospects and who have probably achieved characteristics associated with the reproductive success is an invaluable More attractive women will prefer ability to acquire resources. (Buss, 1989) resource. more attractive men in terms of physical characteristics, financial If another attractive woman finds a prospects, and parenting qualities. man attractive, the assumption would be that the man possesses attractive qualities concealed from her. (Hill & Buss, 2008) Edison Tan Evolutionary Psychology Singapore Management University Context Effects on Men’s Mating Strategies Position of Power Contrast Effect Men who enjoy high status and income can attract more Men who view pictures of more attractive women tend to desirable women. They place even more emphasis on physical judge their partners as less attractive subsequently. (Kenrick et al. attractiveness, youth, and femininity. 1994) Men lacking in resources and status may have to settle for less. They also felt less committed to, less satisfied with, less serious about, and less close to their partners. The assumed abundance of attractive women may tempt a man to consider switching mates. Edison Tan Evolutionary Psychology Singapore Management University Luxuries and Necessities Necessities – mate qualities, which are hygiene factors that are prioritized over all else Luxuries – mate qualities that are good to have, particularly when necessities are met. Budget Allocation Method (Li et al., 2002) Represented personal mate value with “mate dollars” Asked participants to “purchase an ideal mate” given a low, medium, or high budget. Traits purchased with lower budgets are necessities Traits purchased only when the budget expanded are luxuries People can afford to be choosier in a broader array of characteristics as personal mate value increases. Edison Tan Evolutionary Psychology Singapore Management University  04 Homosexuality Edison Tan Evolutionary Psychology Singapore Management University Mystery of Homosexuality Relatively understudied Evidence of genetic influence Not singular phenomena with distinct facets that do not always coincide Gender identity (do you identify as male, female, both, or neither) Sexual attraction (e.g., who you fantasize about or desire to have sex with) Sexual behavior (who you actually do have sex with) Edison Tan Evolutionary Psychology Singapore Management University Lesbianism Female sexuality tends to be more fluid and flexible over a woman’s lifespan. (Baumeister, 2000) Homosexuality in men tends to emerge early in life Two broad classes of lesbian women with biological and psychological distinctions: “Butch” – more masculine, dominant and assertive Higher Testosterone Similarity with heterosexual women More masculine waist-to-hip ratio Preferences for kindness, dependability, and emotional More permissive attitude toward casual sex stability in a long-term mate. Less desire to have children Experience greater sexual jealousy Differences More tolerance of a larger age gap. (Conway et al., 2015) “Femme” – more feminine, sensitive, and cheerful Preferences for similar height. (Valentova et al., 2016) Place greater importance on financial resource Edison Tan Evolutionary Psychology Singapore Management University  Potential Explanations Male Choice Hypothesis Kin-Altruism Women may engage in sex with other women because men like Homosexuality may evolve if homosexuals invest heavily in it. Lesbianism may be a mate attraction and retention tactic. genetic relatives. (Apostolou & Cristoforou, 2018) Problem: Problem: Mixed-emphirical findings Majority of women are exclusively attracted to men Gay men are not more likely to funnel resources to genetic Does not explain why some women are exclusively attracted relatives than heterosexual men to women Gay men are slightly more likely to be outcast by their family Edison Tan Evolutionary Psychology Singapore Management University  Potential Explanations Female Fertility Hypothesis Homosexuality may evolve if it produces an increased reproductive rate in the female relatives of male homosexuals and compensates for the lower rates of reproduction of gay males. Can occur in resource-stratified societies where women with highly attractive feminine and fertile qualities “marry up” in social status. Maternal female relatives of gay males indeed produce significantly more offspring than the maternal female relatives of heterosexual men (Iemmola et al. 2009) Edison Tan Evolutionary Psychology Singapore Management University  Potential Explanations Alliance Hypothesis Homoerotic behaviors may serve a function of facilitating alliance formations (Muscarella, 2000) Homoerotic behavior by young men with older men provides a strategy for gaining allies, boosting themselves up the status hierarchy, and ultimately gaining greater sexual access to women. Support from cross-species comparative studies and historical data from ancient Greece. Problem: Explanation restricted to a minority of cultures, does not apply to the majority of young men No evidence to suggest that men who engage in homoerotic behaviors succeed in alliance formation more than those who do not. Edison Tan Evolutionary Psychology Singapore Management University  Discussion Edison Tan Evolutionary Psychology Singapore Management University Nice Guys Finish Last? Why do women like “bad boys”? Do “bad boys” inherently do better than “nice guys”? Consider: What characteristics do “bad boys” and “nice guys” possess? What adaptive problems would those characteristics solve? What contextual factors would affect the fitness advantages and disadvantages of preferring “bad boys” and “nice guys”? Edison Tan Evolutionary Psychology Singapore Management University  Who’s bad, who’s nice anyway? “Bad Boys” “Nice Guys” Dominance Kindness An inclination for behaviors that employ forceful or Tendency to deliver material resources or other forms of social competitive tactics in order to promote desired outcomes support to another at a cost to oneself or that communicates and/or achieve status in a social hierarchy one's willingness to do so. e.g., aggressiveness, assertiveness, boldness, braveness, e.g., affectionate, considerate, generous, gentle, helpful, kind, competitiveness, dominance, leadership, power, strength, sensitive, supportive, sympathetic, thoughtful take-charge, and toughness. Trustworthiness Tendency to adhere to stated intentions and to honor commitments over time. e.g., committed, dependable, devoted, honest, loyal, reliable, sincere, trustworthy Edison Tan Evolutionary Psychology Singapore Management University  Nice to Who? Toward one's close Toward Self Towards Others friends and family Both sexes should prefer partners who are People value the welfare of friends and family Both sexes prefer lower levels of kindness and extremely high on kindness and trustworthiness with whom they have fitness or cooperative trustworthiness towards others. and low on dominance. interests; in turn, this predicts preferences for their romantic partners to exhibit high kindness and A partner who is extremely kind and trustworthy Consistent material and social support over trustworthiness but relatively low dominance toward people outside the pair bond will end up in time toward these individuals. possession of fewer resources that could be Refrain from extra-pair affairs invested in a mate and offspring. Avoidance of physical injury or coercion For women, a potential mate’s dominance towards others signals the ability to extract resources and ability to protect the family and even higher- quality genes. Edison Tan Evolutionary Psychology Singapore Management University Nice to Who? Men’s Preference Women’s Preference Edison Tan Evolutionary Psychology Singapore Management University Nice to Who? Men’s Preference Women’s Preference Edison Tan Evolutionary Psychology Singapore Management University  WHEN do Nice Guys Finish Last? Niceness appeared to be the most salient factor when it came to desirability for more serious relationships. Edison Tan Evolutionary Psychology Singapore Management University WHEN do Nice Guys Finish Last? Physical attractiveness appeared more important in terms of desirability for more casual sexual relationships. When compared to physically less attractive men (in the study: mismatched condition), jerk Todd is preferred as a partner and one-night stand. Edison Tan Evolutionary Psychology Singapore Management University NEXT WEEK: Short-Term Sexual Strategies & Problems of Parenting Edison Tan Evolutionary Psychology Singapore Management University