Human Sexuality Final Exam
Byproduct- define and give examples
-emerges as a side effect of adaptations (can have positive, negative or no effect on survival, reproduction) ex: male nipples are byproduct
Ovulatory shift hypothesis
-extra pair attraction and flirtation should occur more at high fertility -for some women more than others: the ovulatory shift should be greater for women whose partners do not display markers of heritable fitness
Parental Investment Theory: Obligatory Biological Costs, Reproductive Potential, Paternal Uncertainty
-females have higher obligatory biological cost and lower reproductive potential, men opposite -men have paternal uncertainty, women have maternal certainty
Markers of heritable fitness
-genes that promote the health, robustness or attractiveness of offspring -evolved mechanism in females--> -lead women to individuals with indicators of good genes--> -ancestral females with these preferences would have produced more viable offspring--> -traits preferred most
Potential benefits of short-term mating for women
-genetic diversity in offspring -reduced in-pair conflict
Why are some trait markers of heritable fitness
-heritable genetic benefits passed from a parent to offspring, enhancing offspring viability or mating success -few mutations -often high in testosterone -females should value markers when selecting a short term mate when in control of own success
What are the different ways of defining sexual orientation?
-identity "I am a gay person" -fantasies "I fantasize about guys" -preferences "I find guys attractive" -behaviors "I have sex with guys" -genital arousal "I become erect when I see guys"
Sexual antagonistic co-evolution
-one sex evolves a trait that gives it an advantage in mating -the other sex evolved a counter-response to neutralize that advantage ex: sperm in fruit flies
Adaptation- define and give examples
-trait that evolved in response to specific challenge faced by the organism. Aids in survival, reproduction etc. ex: female nipples facilitate breast feeding
9 dimensions of sex
1) chromosomal sex (XY vs. XX) 2) Genetic sex (SRY vs. no SRY) 3) Gonadal sex (testes vs. ovaries) 4) Hormonal sex (testosterone vs. estrogen) 5) internal genitalia (wolffian vs. mullerian ducts) 6) external genitalia (penis vs. vulva) 7) brain differentiation (male typical vs. female typical) 8) gender identity (feel male vs. female) 9) gendered behavior (act male vs. female typical)
What two reasons are given for testosterone
1) suppresses immune system 2) raised metabolism
Biological Evidence for Sexual Orientation
+Genes: Xq28-2 studies say yes, 2 studies say no +Twin studies- identical: 100% of genes will be the same (50/100 twins will be gay) fraternal: 50% of genes will be the same (25/100 twins will be the same) +Brain anatomy: INAH-3 in humans and sheep +Older brothers: gay men tend to have more older brothers (each older brother increases the odds of male homosexuality by 33% +Childhood Gender nonconformity: 75% feminine boys +Hormones: can make "gay rats" by unusual hormone levels, weak evidence for humans +2D:4D ratio: men with shorter pointer finger = more testosterone (longer pointer = less testosterone)
Lisa Diamonds Studies on Sexual Orientation
-89 women, age 16-23 in 1995 -followed their lives for 10 years -43% lesbian, 30% bi, 27% unlabeled -6 assessments, 11% attrition Results: almost half of the sample changed their label 1+ times over the 10 years
Types of choosiness: post conception, + Bruce effect
-After the egg has met the sperm -Sperm competition: sperm from multiple males in the reproductive tract, male who produces most viable sperm will sire the offspring bruce effect: -female rodent has sex with a male -shortly after, introduce female to new male -Embryo is spontaneously aborted -female mates with new male 1) to prevent infanticide 2) good genes 3) here "choosiness" occurs after conception
What are three traits that arise because of intrasexual competition
-Fuels development of physical/mental traits to aid -Fuels increased body size and strength in males -fuels development of muscle mass
Strategic Pluralism theory
-animal mating strategies are dependent on their own sex, current condition and attractivness -attractive males pursue more short term mating strategies. females sometimes secure longterm mateship with one male but then additional short-term mates
What were the methods of the Gueguen 2009 dance club study? The key findings?
-approached 211 women and asked them to dance -recorded whether the woman said yes or no, and where she was on her ovulatory cycle -Results: when ovulating 35% said yes, leutal 39%, fertile 59%
MHC genes
-code for immune system function -matings between individuals with dissimilar MHC produce offspring who are more resistant to a wider range of parasites
Sexual strategies theory
-consistent with parental investment theory, there are different costs to reproduction for men and women -both men and women seek short term and long term matings but sometimes do so for different reasons and to different degrees
External female genitalia
Labia Majora Labia Minora Clitoris
Intersex definitions
Medical: atypical sex chromosomes, gonads or genitalia Social: identity claimed by people with atypical chromosomes/gonads/genitalia (ex: like man, women, straight etc.)
Modules and Massive modularity
Mental modules: adaptive challenges-->evolved motivations-->adaptive behavior Massive modularity: the human mind is chock full of many different software programs
Gonads
Ovaries: female gonads, where eggs live (start with 400,000) Testes: male gonads, produce and store sperm
Identity management
Assimilation: process by which minority groups are absorbed into a larger culture Conversion: changing one's actual identity Passing: (trying to) completely conceal your identity from others Covering: not completely hiding your identity, but nor advertising it either Reverse covering: a demand or expectation that you perform your stereotyped identity Flaunting: openly displaying the characteristics of your identity (normals vs. Queers)
What are the two types of orgasm in women
Clitoral: repeated rhythmic stimulation by the man or woman during sex/masturbation G-spot/vaginal: small bundle of nerves 2 inches past opening to the vagina
Explain all the key traits associated with pAIS and cAIS (ovaries? sry? testes? male internal genitalia or female? external?). Know what pAIS/cAIS stand for and how it is produced (be able to write it out, don't just use acroynm).
Complete Androgen Insensitivity Syndrome: XY, SRY present, Testes present, testes release MIH, testes release testosterone, testosterone is converted to DHT (default is always to go female, unless something intervenes) -Cells recognize NO androgens -Appears female-typical externally, has shallow vagina, but inside body no uterus and has testes Partial Androgen Insensitivity Syndrome (pAIS): -cells recognize some androgens -Appears male with small penis
Explain all the key traits associated with CAH (ovaries? sry? testes? male internal genitalia or female? external?). Know what CAH stands for and how it is produced (be able to write it out, don't just use acroynm).
Congenital Androgen Hyperplasia •XX chromosomes •No testes •No SRY •Adrenal glands pump out androgens, causing enlargement of clitoris
Predictor, Outcome, and findings of Garver-Apgar et al. MHC Study
Predictor: percentage of MHC sharing Outcome: female sexual responsivity to partner Findings: less MHC sharing led to an increased female sexual responsivity to partner
Proximate vs. ultimate explanations for the orgasm
Proximate: mechanically, how does the trait/behavior/preference work? -glans directly stimulated in men but not women -duration -sex drive and arousal during sex -fatigue/stress/tense -hormone level ultimate: why the trait/behavior/preference exists -fitness of human females
Consequence of Intrasexual competition and 4 ways it happens
Restricting female choice 1) males physically intimidating rivals 2) males physically intimidating partners 3) warfare and capture 4) rape
XX vs. XY
XX: female XY: male
Why does passionate love fade?
as relationship solidifies, it becomes more predictable
Limerace
characterized by a strong desire for reciprocation of one's feelings -fueled by uncertainty -creates arousal -rush of dopamine
2 types of love and definitions
compassionate love: high intimacy, high commitment passionate love: high intimacy, high passion
What are the adaptationist explanations for female orgasm? Be able to list and define at least 3.
female orgasm serves an important function in promoting reproduction or mate selection 1) Upsuck hypothesis: orgasm creates contractions in the uteran wall which helps bring the sperm up into the uterus (not proven in humans) 2) Poleax hypothesis: after an orgasm the female becomes sleepy causing her to lay down, which allows the sperm to swim without going against gravity 3) Facilitate bonding: it takes femals longer to orgasm with the partner which facilitates bonding in the long run
What are the byproduct explanations for female orgasm? Be able to list and define at least 3
female orgasm serves no clear function. it exists in females simply because the physiological system underlying orgasm is present and adaptive in males (female orgasm in like the male nipple) 1) Extensive clitoral stimulation often needed- often challenging for many women even with concentrated directed effort 2) Long time and directed effort vs. species typical number of thrusts 3) Clitoral location 4) Animal orgasm?
Mate choice: direct benefits
females choose males who can provide "direct benefits" that immediately benefit them or their offspring such as food, territory, child care etc.
Intersexual selection (mate choice)
fuels development of methods to attract the other sex
SRY Genes
genes that code for development of testes, typically Y
Compatible genes
genes that would mix well with her genes when producing offspring
Desire for sex: gender or no difference?
men generally want sex more than women
How might sex ratio change mating patterns based on parental investment theory
sex ration: number of men vs. women in population *men and women have overlapping but different mating strategies when one sex is fewer they are more able to pursue their mating strategy
Dual mating hypothesis
some females engage in dual mating by securing resources and parental investment from a longterm partner and genes from males with markers of heritable fitness through surreptitious extra pair matings
3 most common concerns with sex among men
1. performance anxiety "am I good in bed?" 2. erectile dysfunction "will I get hard" 3. premature ejaculation "will I last long enough"
Evolutionary Psychology vs. Biosocial Model
Evolutionary: Evolution --> physical sex differences -->Psychological sex differences Biosocial: Evolution-->physical sex differences-->different social roles-->psychological sex differences
Sexual Dimorphism
In many species there are sex differences in size, weapons, and ornaments
Describe both of Aron's studies. List 2 ways to enhance sexual and relationship satisfaction based on these studies
Obstacle course: -couple had to do silly tasks together -doing something novel can improve relationship satisfaction Bridge: IV: bridge type (stable or scary) DV: call student research assistant? Results: men who walked on scary bridge called the assistant (attributed their arousal to her)
Sperm & Egg
Sperm: carries 23 chromosomes which is either X or Y Egg: 23 chromosomes one will be an X
Intrasexual competition
contests, fighting, and other competition between members of the same sex.
Estrus
the periodic state of sexual excitement in the female of most mammals that immediately precedes ovulation and during which the female is most receptive to mating; heat.
Sexual Selection
the process by which animals attempt to maximize their reproductive success, primarily though intrasexual competition and inter sexual selection
Implications of parental investment theory sex differences for mating strategies
the sex (male) that invests less in reproduction/parenting effort will be relatively more open to sexual encounters with no investment of resources/parenting effort. -the female that invests more will be choosier and demand more in terms of resources/parenting effort/good genes, placing a relatively higher cost on males to display these traits to secure mates
What are the orgasm gaps
there is a difference between heterosexual men and women, lesbians fall in the middle
Mate choice: good genes (indirect benefits)
traits that only males with healthy robust bodies can produce these traits. Females who choose these males produce healthier offspring