Sexual Orientation and Development-Martin and Sweeny Flashcards
What is the Parental Investment Theory? When is it more beneficial for a female to have a male vs. female offspring?
- males elevate their fitness by having multiple sexual partners and making sure the women can raise their children (resources) –> polygynous mating system
- females are limited in the amount of offspring they have and must invest in their offspring in order to maximize their fitness
- female offspring always promote the mother’s fitness
- male offspring: must compete and require more investment than females.
- better to have males when there are plenty of resources
how can sex ratios be controlled in non-primate mammals? non-human primates?
- non-primate mammals: fat females can selectively abort female offspring because they have enough resources for males
- non-human primates: sex ratio depends on the quality of the habitat (females in low quality and males in high quality)
What are some examples of how humans control sex ratios? (Rajput case and Portugese Case)
- Rajput: in Northern India, elite clans have no daughters (abort them b/c no caste to sell them to). Sub-elites pay dowries to get their daughters into higher classes and impoverish their sons. Poor castes want daughters so they can sell them
- Portugese case: 1st born remain near, later orb send to crusades and died–> redundant daughters –> cloisters
What is the Kin Selection Theory?
you can gain fitness by helping your close relatives to reproduce or raise their offspring
How would homosexual offspring benefit the mother in response to environmental conditions?
- if the environmental conditions are bad (low resources), having a homosexual male (acts more like a girl in the sense that they avoid danger and don’t go to war) can increase the mother’s inclusive fitness
- prenatal stress can also lead to more homosexual male offspring–> high in WWII
-age of mother=higher in homosexual males
What is Turner’s Syndrome?
XO female
infertile because no ovaries and no estrogen
female is default!
What will result if a person has mutated androgen receptors (androgen insensitivity syndrome)?
- Will look like woman
- this receptor is necessary for testosterone to work –> no masculinization of the brain because no testosterone receptor
- XY look like female, including female looking genitalia (actually is benign vaginal pouch with internal testes and no uterus)
- will not hit puberty and can’t reproduce
(androgen receptor is on the X chromosome)
What is 5alpha-reductase responsible for? What happens if this is messed up?
- this enzyme converts testosterone to dihydrotestosterone –> leads to dev’t of the penis and scrotum
- if this is messed up–> no penis or scrotum but masculinized brain–> person is male
What is congenital adrenal hyperplasia?
- female produces too much testosterone because blockage of cortisol pathway–> shunting to testosterone pathway.
- masculinization of the brain–> more male-like behavior
- sexual orientation: prefer females but only 30-40% are lesbians
How does the number of males surrounding a fetus in utero affect their development?
-2M females (next to 2 males in utero) are exposed to a lot more testosterone–> more masculinized skeletal systems (longer arms and legs) and more likely to become lesbians
What is sexual fluidity? Is it more commonly seen in males or females?
- variability in attraction and behavior across a lifespan
- more in women–> more socially accepted?
What things contribute to the formation of gender identity?
- parents
- culture
- child’s external genitalia
- genetic influence
What is the criteria for Gender Identity Disorder in kids? (DSM IV)
-A strong and persistent cross-gender identification. In children, the disturbance is manifested by 4+ of the following:
1. repeatedly stated desire to be, or insistence that he or she is the other sex
2. in boys, preference for cross-dressing or simulating female attire;
in girls, insistence on wearing only stereotypical masculine clothing.
3. strong & persistent preferences for cross-sex roles in make-believe play or persistent fantasies of being the other sex
4. intense desire to participate in the stereotypical games and pastimes of the other sex
5. strong preference for playmates of the other sex
- Persistent discomfort with his or her sex or sense of inappropriateness in the gender role of that sex.
- Children: Boys “my penis is disgusting. It would be better not to have one.” –Girls “I don’t like sitting down to urinate. I want to have a penis!”
How does GID appear in adolescents and adults?
- In adolescents and adults, the disturbance is manifested by symptoms such as a stated desire to be the other sex, frequent passing as the other sex, desire to live or be treated as the other sex, or the conviction that he or she has the typical feelings and reactions of the other sex.
- disturbance=preoccupation with getting rid of primary and secondary sex characteristics (i.e. request for hormones, surgery, or other procedures to physically alter sexual characteristics)
- The disturbance is not concurrent with a physical interesex condition.
- The disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.
How can dopamine affect sexuality?
- DA =stimulatory effects
- D2 receptor antagonists (antipsychotics)==> block DA–> decrease sexuality
- inhibit prolactin
