Perspectives and Sexuality - Exam 1 Study Guide | ANT 2301, Study notes of Psychology of Sex

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Week One- Perspectives on Sexuality

What is Sexuality?

 How individuals experience/express themselves as sexual beings  Can be explained through different perspectives: o Biologically: Addresses sexual contact, sexual attraction o Sociologically: Cultural, legal, and political sexual expectations & standards o Philosophically: How individuals/groups think about sex (morally, ethically, theologically, spiritually, etc.)  Primarily look for explanation of sexuality in natural selection (Darwin) o The main force driving sexual selection is to pass one’s genes on to the next generation  The more offspring bore, the higher fitness of an individual’s genes.

How is Sexuality Determined?

 Prehistory: Most of sexual knowledge comes from assumptions, inferences. o Venus of Willendorf: Earliest evidence of symbolic ideals of sex (enhanced sexual features)  Biology: The body can tell us about sexual selection  Art, Symbolism, and Writing: Reveals cultural perspectives on sex

Sexuality in History

Ancient Mediterranean

 Includes some of the earliest writing forms o Concepts of what activities, sensations, etc. are considered “sexual” o Accounts of STDs, menstruation, circumcision, contraception, prostitution

The Hebrews (1000-200 BC)

 Rules regulated by Hebrew Bible regarding what is/isn’t sexually appropriate o Rules about sexual behavior  Acknowledges & Defines love

The Greeks (1000-200 BC)

 Distinguish between love and sex o Mythological stories to reinforce distinction: Aphrodite (love) & Eros (sex)  Institutionalize homosexuality o Behavior based, not orientation based. o Idealization of the male form o Pederasty common  Typically platonic love, sex only sometimes occurred  Consumption & Education lead to manhood

The Romans (500 BC-700 AD)

 Marriage & Sex were social moves, meant to improve one’s social standing.  Permissive of homosexuality until introduction of Christianity o Banned under Christianity

India (Beginning around 400 BC)

 Belief of Karma (Hinduism) affected perspectives on sexuality  Kama Sutra o Not just an “instructional manual,” but also a moral guide o Addressed love and family in addition to sex.

China (Beginning around 200 BC)

 Practiced polygamy o Established power, wealth of an individual  Tao belief in Yin & Yang o Yin: Female- weak, submissive o Yang: Male- dominant, strong, assertive  Both yin & yang necessary for balance.

Moche, Peru (100-800 AD)

 Known for rich, monumental architecture o Structure sites of human sacrifice  Sex Pottery.

Early Christianity (Beginning around 50 AD)

 Jesus very liberal in his thinking of sexuality o Male and Female considered equals.  Stricter sexual regulations enforced by St. Paul and later followers  Typically sex is associated with sin in Christianity

The Middle Ages (500-1400 AD)

 Early in the period: All sex outside of marriage considered sinful, was forbidden  Later in period: o New ideals of women developed  Not all women are “temptresses” o Thomas Aquinas: Establishes sexual laws  Any non-procreative sexual activity was illegal

Islam (Around 500 AD)

 Developed with Jewish & Christian roots  Muslims: Very strict rules of gender roles, modesty o Women are subjugated to their husbands, though men are often allowed harems.

The Renaissance (Beginning around 1300 AD)

 More focus on mankind’s place in the world  Rejuvination of Sexuality  Increased women’s roles in society o Though later in the period- backlash against sexuality of a woman

The Reformation (Beginning around 1500 AD)

 Martin Luther & John Calvin o Sex is natural o Marriage is a companionship with equal partners

The Enlightenment (Beginning 1700 AD)

 Exploration of female sexuality  Homosexuality heavily condemned

Victorian Era (1837-1901)

 Public vs. Private sexual behavior o Public: Very sexually conservative o Private: Complete opposite  Prevalence of porn, adultery, prostitution  Return of Chivalry o Belief that women are delicate and must be protected.

Puritans (Begin around 1600)

 Severe sanctions for sexual behaviors o Caused groups to flee and regroup with others with similar ideals and morals

Early US (1700-1800’s)

 Late 1700’s- More liberal sexual attitudes  Slavery (an issue of human rights) impacts sexual conduct

o Settlers used open sexuality of minorities (Mexicans, Native Americans) as a reason to disdain & oppress them.

The 19th^ Century

 Free Love movement o Saw marriage as the sexual slavery of women  Increase in medical studies/definitions of sexuality  Comstock Act of 1873 prohibits mailing of sexually obscene publications.

The 20th^ Century

 Social Hygiene Movement o Blood tests before marriage to prevent spread of STDs o Police action against prostitutes  Sexology o Alfred Kinsey: Importance of sex greater than originally believed o Masters & Johnson: Studied physiology of sexual response  The Sexual Revolution o 1920’s: Flapper era, enforced strength & power of women and their sexuality  Rise of feminism  Gay Liberation o Stonewall Riot (1969)- Bar raided by police because it was for gays, triggered a major riot.  Queer Theory o Recognizes legitimacy of homosexuality

The 21st^ Century

 Rise in popularity of plastic surgery o Reflects ideals of unnatural images of beauty as seen in the media/pornography. Theoretical Perspectives on Sexuality

Evolutionary Perspectives

 Biological Theory: Emphasizes biology behind sexual behavior (genetics, etc.)  Sociobiology: Sexual behaviors are a result of natural selection in evolution  Evolutionary Psychology: Influence of psychological mechanisms and environmental factors on sexual behavior.

Psychological Theories

 Psychoanalytic Theory: (Freud) Id, ego, superego, libido, psychosexual development, erogenous zones  Social Learning Theory: Classical conditioning (reward/punishment) on sexual behavior  Cognitive Theory: Our thoughts are responsible for our (sexual) behavior

Sociological Perspectives

 All societies regulate sexuality in different ways (social norms, taboos, expectations, etc.)  “Appropriate” behavior is dependant on the culture  Symbolic Interaction Theory: Sexual behavior is influenced by prior learning  Reiss’s Theory: Sexuality is about power, forming bonds.

Social Messages about Sexuality

 Agency: Cultural ideal that you either interact with or oppose your culture (Ex: religion, family, peers, media of an individual)  Ideals of a Culture vs. Actual Reality: what we say we do vs. what we really do Genetics in Sex

Genetics are a relatively new concept

• An allele is one of two or more forms of the DNA sequence of a particular gene
• The genotype is the genetic constitution of a cell, an organism, or an individual usually with reference to a specific character under consideration
• A phenotype is any observable characteristic or trait of an organism such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior

genotype + environment → phenotype

• Genes -unit of heredity in a living organism - Chromosomes: Strand of DNA in the cell nucleus that carries the genes - Meiosis Cell division that produces reproductive cells in sexually reproducing organisms - Recombination “Gene mixing”
• Intraspecific selection Competition within a species
• Interspecific selection Competition between 2 different species for resources
• Gametes that are small, numerous, and cheap = males
• Gametes that are large, rare, and costly = females
• Disruptive selection can produce two quite different gametes (and sexes)

The Riddle of Sex

• Darwin: Natural Selection
  • Genetic changes take hundreds/thousands of years to be noted in a species
• Adaptation occurs through natural selection so individuals are better suited for their environment - Changes can be structural or behavioral
• Some species are able to switch from asexual to sexual reproduction depending on circumstances (Ex: Strawberries, Komodo Dragons)
• So, why isn’t every species asexual?
  • The Red Queen Hypothesis: Refers to disease pathogens, etc. that all would be susceptible to if asexual reproduction always occurred (Asexual reproduction=Cloned offspring)

Week Two- Sexual Selection

What is Sexual Selection?

The struggle by one sex for mating with the other sex

Different Types of Sexual Selection:

 Intra-Sexual Selection: (Male-to-Male Competition) Males fight and compete for access to females  Inter-Sexual Selection: (Female Choice) Females either wait to mate with victor or actively chooses a male as a mate. o Choice typically based on physical traits of male.

Male vs. Female Choice

Overall Strategy: To maximize reproductive success (“selfish gene”)

 Males: Want to mate as much as physically possible without injury.  Females: Want to choose the ”most fit” mate o This is based on some idea of good genes- beauty, dominance, etc.  Conflict in selection arises due to different goals between males and females.  Polygyny : One male, multiple females a. Male typically gets more decorated to attract females  Monogamy: Females typically more decorated.  Lek: Group of males from which females are choosing

Female Choice

 Because females typically invest more in their offspring than males do, they have more to lose in making the choice for the “right” mate o Females are therefore expected to be more choosy

Female Choice favors 3 kinds of traits

 Traits that directly increase fitness of female o Ex: Male will defend, protect, or provide  Traits that indicate good genes, which enhance fitness. o Ex: Peacock eyespots  Nonadaptive but Conspicuous traits o Ex: Frog mate call that’s easier to hear  Traits females may look for: o Dominance o Unfamiliarity  Helps avoid the risk of inbreeding o “Good genes”  Health, strength, etc. o Variety of Mates  Confuses paternity, decreasing risk of infanticide Preference vs. Choice  Preference: Desire/propensity that an individual possesses  Choice: An action made by an individual that can be observed/measured. What actually happens o Depends on behavior of both genders  Typically, females that are older and have a higher rank are more able to refuse male coercion as opposed to younger, lower-ranked females. Intrasexual Selection  Male-to-male competition leads to more physical strength, larger canines, and even larger testes o “Sperm Competition”: Larger testes = more sperm = higher chance of reproducing  In multi-male, multi-female groups, females often mate with several males so selection favors males who produce more sperm.  In this case, males typically have larger testes o Physical Size/Canine Size: Advantageous in fighting other males Sexual Dimorphism

Strong selection pressure that makes males bigger than females

o More prevalent in polygyny o Caused by male competition  Operational Sex Ratio: Includes adult sex ratio, duration of breeding season, birth internal, length of estrus period, number of cycles to conception o OSR predicts dimorphism in primates  Sexual dimorphism not significant in monogamous communities Problems in Research  Male-to-male competition intensity is hard to measure  Length of birth interval can affect intensity of competition  Other factors (food, habitat, etc.) are competed for as well- not strictly competition for a mate.  Explanation from Bateman (1948): The more females around a male, the higher the male’s reproductive success (RS) The more males around a female, little to no effect on the female’s RS. Female-to-Female Competition  Occurs when males are scarce or when males provide something of value to females (Ex: food, territory, defense) o Males typically then “carry the clutch” in terms of caring for offspring  Triver (1972): Whichever gender invests more in the offspring is the choosier gender in picking a mate.

o Due to the evolution of lactation only in females in primates and mammals, the females must typically be the ones to provide care for the offspring.  Potential Reproductive Rate/PRR: Amount of offspring one sex could have with unlimited access to the other (Clutton-Brock & Parker- 1992)  Even when males invest greatly, they still have grater PRR; Even when females invest little they have less PRR.

Infanticide

A male reproductive strategy of killing offspring that males in a group do not know

to be theirs

 Associated with changes in male residence or status  Occurs so the mother can be fertile again for the male. o Females have evolved responses to threats of infanticide

Hominin Dimorphism

Australopithecines (4-2 mya)

 Large degree of dimorphism (compare to gorillas)  Chimp sized brain & Bodies  No projecting canines o Suggests lower levels of fighting in competition

Homo Erectus (2 mya-600 kya)

 More dimorphic than modern humans, less dimorphic than Australopithecines  Significant increase in brain & body size  More readily hunting and scavenging, diet depends more on meat  Hand-axes o Hand Axe Theory: Axes are what are being selected for- the better the axe made, the higher the chance of the female choosing that male. (Nowell & Chang) o Flaws in proving the hand axe theory- the following must be proven:  Hominins are attracted to symmetry (only point that can sort of be proven)  Quality in manufacturing axes is heritable  Axe directly represents fitness.

Week Three- Sexual Characteristics

Primary Sexual Characteristics

 Includes any reproductive organs  Male: Penis, testicles  Female: Vagina, Cervix, Uterus, Ovaries  Reproductive organs develop at Week 10-12 in fetal development o Until week 9, all reproductive organs look the same in both male & female fetuses.  Further protrusion of the genital tubercle in the male to form the penis.  Labioscrotal folds evolve into the scrotum in males, and the labia in females.  Babies are “fully equipped” at birth o Erections seen in male infants o Vaginal lubrication seen in females o Both produce testosterone and estrogen from birth.

Secondary Sexual Characteristics  Develop after puberty  Traits that distinguish the sexes of a species o Includes body hair, fat distribution, etc. o Not directly part of the reproductive system

Male Secondary Characteristics

 Hair o Pubic region typically first to develop hair  Starts as darkening around the penis, spreads upward. o Facial hair begins at the corners of the mouth and spreads to the midline and eventually to the rest of the face. o Body hair (arm pits, legs, arms, buttocks, back) develops way before the completion of facial hair growth. o Hairline changes from bow-shaped curve to a line with two wedged indentations.  Face Shape o Face becomes longer, less round. o Eyes, nose, and mouth expand to better fill up the head. o Chin typically grows, becomes more defined.  Vocal Changes o Growth of the larynx creates larger, stronger sound o Thyroid cartilage increases, creating the Adam’s Apple o Vocal chords lengthen and thicken.  Body o Increased weight, strength, and overall size of body  Due to increased testosterone levels

Female Secondary Characteristics

 Hair o Pubic region develops hair first  Begins as darkening above vagina, then spreads upward. o Body hair develops slightly later  Breasts: Tanner Stages: o Tanner I: No glandular tissue, around age 10/younger o Tanner II: Breast buds form, small area around glandular tissue, age 10-11. o Tanner III: Breasts become more elevated, extend past areola, age 11.5- o Tanner IV: Increased breast size and elevation, age 13- o Tanner V: Breasts reach final adult size, age 15  Pelvis o Broadens to a broad, oval outlet  Flares at the hip o Increase in fat cells around buttocks and thighs Fertilization  Involves the fusing of a sperm with an ovum o Enzymes produced by the sperm allow it to penetrate the outer layer of the egg  Sperm plasma fuses with egg plasma, sperm head disconnects and travels down the Fallopian tube to the uterus. Embryonic Development  Week 1-3: The brain, spinal cord, heart, and gastrointestinal tract begin to form.  Week 4-5: The heart starts to beat and blood starts to flow.  Week 6-8: Facial features are beginning to develop  The fetal period begins at the end of the 10th week of gestation Fetal Development  Week 10-12:

o Reproductive organs develop o Permanent organs preceded by a set of embryonic structures. Will disappear almost completely before the end of fetal life.  Structures known as Wolffian (male) & Mullerian (female) ducts, or the mesonephric & paramesonephric ducts (respectively) Child Development

Early Childhood (2-5 years)

 Crucial period of physical development  Begin exploration of bodies o Begin noticing difference between males and females o (Toilet training occurring during this time)  No intentions or ideas of sexuality

Middle Childhood (6-12 years)

 Overt sexual behavior more common, though influenced by surrounding culture. o Begin to learn what is and is not culturally acceptable  Begin questioning sexual functions o “Birds and the Bees” Puberty

Male Puberty

 Changes (rapid growth) in primary sexual characteristics  Varies from person-person, but occurs around age 10-  Organs grow steadily during childhood, then rapidly increase during puberty.  Brain begins releasing hormones that stimulate testosterone production which stimulates sperm production

Female Puberty

 Changes (rapid growth) in primary sexual characteristics  Eggs ripen, one approximately every menstrual cycle (28 days) o Passes through fallopian tube and passes through uterus, then later passes through the vagina to the outside genital opening.  Menarche: A girl’s first menstruation and first definite indication of a girl’s sexual maturity. o Pituitary gland secretes a hormone that stimulates estrogen production  Increased estrogen eventually causes maturation and growth of fallopian tubes, uterus, and vagina. o Girls that are heavier typically menstruate sooner than underweight girls African American girls typically menstruate earlier (age 12) than Caucasian girls (age 13)

The Menstrual Cycle

 Lining of uterus builds up in preparation for pregnancy

 With no pregnancy, menstruation occurs and the lining of the uterus and an

unfertilized egg shed and is released through the vagina as blood and tissue.

When you can procreate, you are biologically an adult

 Males: Ejaculation  Females: Menstruation  (Both occur prior to full biological maturity) The Hadza  Located in Tanzania, hunter-gatherer group  Females often 16-17 before first menstruation.

Sex Play

 Children encouraged to perform acts of sex o Meant to be practice for their adulthood o A way to get promiscuity “out of their system” before marriage.

Week Four- Mating Systems

Social Organization

 Majorly based on food o Needed to sustain life in a community o Provides energy  Different metabolisms mean different energy needs (depends on activity, growth rate, reproductive efforts) o The bigger the individual, the lesser the quality of food needed  Small animals- Need small amounts of high quality food  Large animals- Need large amounts of lower quality food o All diets require some form of protein and some form of carbohydrates  Different species “specialize” in their dietary needs (Ex: insectivores, herbivores, etc.) o 4 parts of total energy required:  Basal metabolism : at rest  Active metabolism : amount expended, usually about twice basal  Growth rate : the younger and growing require more  Reproductive effort : females require 25% more in late pregnancy, lactation 50% more

Importance of Diet in Mating

 Food distribution affects ranging pattern of a population o Ranging patterns affect grouping patterns, which influence social organization and mating systems  Most important thing for females: Food distribution o Determines female ranging patterns o Males map onto female ranging patterns, as males are typically less dependent on food.

Promiscuity

 Can occur with or without bonds.  Beneficial for males because they have higher chances of reproductive success when mating with multiple females  Beneficial for females because they have more mates to choose from, create confused paternity, and are more secure with group protection o Confused paternity reduces threat of infanticide.

Polyandry

 2 males and 1 female o The males are often brothers  Ex: Tamarins  Very rare mating technique in mammals o Even more rare to humans specifically (though seen in Tibet)  Evolved because species that have twins (Marmosets, Tamarins) require more adult care of the offspring- so more adults are invested in the offspring in polyandry

Polygyny

 Multiple females and 1 male  Males must capitalize on benefits from polygyny.  Harem mating system

 Typically more sexually dimorphic o Because it’s “all or nothing” for the males in terms of mates.  Typically very territorial  The 1 male defends all of the females and all of their offspring o Only occurs when it is beneficial for females o Males typically have abundance of resources

Multisex Troops

 Multi-male, multi-female  Can be with or without bonds.  Typically, the more the females, the more the males. o Few females (1-5) often only have 1 male.

Promiscuity Without Bonds

 Seen in chimpanzees  No male investment (due to no paternal confidence)  Females dispersed, unrelated, have no bonds. o Creates aggression in males.  No active male-to-male competition o Rather, veral competition (sperm competition)  Some competition- hierarchies typically exist o Higher ranked have slightly more power than those ranked lower

Promiscuity With Bonds

(Ex: Hamadryas Baboons)

 Moderate male investment (due to moderate paternal confidence)  Harems exist within the general population o Home-Ranges: Mate guarding within harems. Monogamy  Limited mating opportunities  High male investment in mate & offspring o Due to high confidence in paternity  Little to no sexual dimorphism o Due to no/little need for competition  Evolves when males’ parental care is vital to successful female reproduction  Can be affected by resources in an environment o The more spread out the females are, the more likely the males are to only have one mate due to inability to acquire additional mates Territoriality  Both males and females actively defend a resource within a territory o Often some type of food source  Territory: Some area (or something) that is small and defendable o Monogamous groups are often territorial  Mate Defense: Males defend females from outside males. (not related to food/other resources) Human Mating Systems

Foragers

 Marlowe 2003 o Argues that women value male provision less where males bring in less food, which results in greater polygyny  In this case, gene shopping occurs rather than resource shopping  Measured using the Standard Cross-Cultural Sample (SCCS)  When provisioning is less important, females should pay more attention to: o Pathogen protection o Gene shopping

 Should cause an increase in (or at least increased acceptance of) polygyny.  Polygyny higher where males contribute less  Polygyny and Pathogen Stress are positively correlated o These also correlate to average annual temperature (or latitude) o Colder climates= Males contribute more, lower polygyny

Traditional Forager View

 The amount of male provisioning determines the mating system- pair bonding o Increased return rates by certain hunters result in increased pair bonds o Females an offspring benefit more with a better provider- doesn’t want additional wives to take away the advantage.