Aggressivity and sex; Homo- or heterosexuality Flashcards
conspecific aggression
part of reproduction
establishemnt of dominance status
access to resources
violence/inappropriate aggrestion
intent to harm and cause injury
assult
murder
types of aggression
anti-predator aggression defensive aggression (fear induced) predatory aggression dominance aggression (inter-male aggression) maternal aggression sex-related aggression territorial aggression (resindent-intruder) irritable aggression (shock induced)
fetus and testosterone
responsible for masculinizing male genitalia
testosterone binds to androgen receptor for masculine genitalia
female disorders- to much testosterone
increased testosterone
testosterone crosses blood- placental barrier and masculinizes female genitalia in female fetus’s intersexed appearance
testosterone is undergoing aromatizaiton to masculinize the brain
Serotonin and aggression
inhibitory pharmacology: 5HT1a and 5HT1b receptor genetics: knockout mouse human impulsivity and hostility there is an inverse relationship between serotonin function and aggression
vasopressin
a facilitator of aggression
established link to aggression
testosterone dependent
interface with serotonin system
vasopression biological diversity- physiology
fluid regulation
carbohydrate metablism
thermoregulation
reproductive function
vasopressin: biological diversity – vertebrate behavior
communication sexual behavior pair bonding paternal/maternal care social memory aggression stress-related disorders
hunger and aggression
low blood glucose levels can make it harder to concnetrate and do simple tasks
it can also make it more difficult to behave within society acceptable norms
neuropeptide Y
released when nutrient levels drop and body gets hungry
functions including increasing food intake
produced in various parts of teh brain, including the hypothalaus, and acts on a variety of receptors
increase in neuropeptide Y increases appetite and is thought to produce an associated change in aggression and aggresive behavior
Pheromones
molecules used for communicatin within a species
orignally defined as chemical substances released by one member of a species causing specific reactions in other members of the same species
volatile pheromone
The volatile pheromone is perceived by the olfactory epithelium.
Impulses are relayed through the olfactory lobes and cerebrum to the hypothalamus.
Gonadotrophin-releasing hormones in the hypothalamus are conveyed over the hypophysial portal veins to the anterior pituitary.
The releasing hormones regulate the output of pituitary gonadotrophins.
Gonadotrophins condition the production of steroid hormones by the ovaries.
The ovarian hormones are deficient or of the wrong kind and a pregnancy-type uterus cannot be developed and maintained.
Young embryos fail to implant, thus terminating pregnancy.
homosexuality among animals
necking and rubbing to sexual excitement is common among male giraffes
common among pygmy chimpanzees
greylag geese can have homosexual unions that last up to 15 years
having older brothers
they say you are more likely to be gay due to a change in hormonal balance in mothers uterus with each additional child
fraternal birth order effect
family studies of homosexuality
homosexual females more likely to have homosexual brothers
brothers concordant for homosexuality were similiar in childhood gender noncoformity
gender nonconformity inherited traight for both males and females
90% of gay or bisexual males had sons who were straight
hormone and prenatal evidence for homosexuality
Prenatal exogenous hormone administration DES H-Y antigen maternal stress testosterone levels handedness finger lengths, 2d:4d Testosterone levels in adulthood
physical differences between gays and straights
Simon LeVay (1991)
The third interstitial nucleus = INAH3 (located in the hypothalamus )
is normally larger in men than in women
in his sample of gay men, the third interstitial nucleus was about the same size as in women
Hypothalamus plays a role in sexual motivation
Critics: it can’t be as black/white as this because of the idea of a continuum
nature and nurture
EBE = “Exotic Becomes Erotic” theory
Sandra Bem: Sexual orientation is a combination of in-born temperament and experiences with other children
Temperament
male typical: aggressive, activity focused
Female typical: relationship-oriented, non-aggressive
temperament guides children toward “Gender conforming behaviors”
Experiences
boys playing sports, “rough and tumble” play, girls play with dolls, pretend activities
Homosexuality results when:
children with a temperament that doesn’t match gender-typical activities are drawn toward opposite sex activities and same sex children are seen as “exotic”
In adolescence, these feelings of the same sex being different, naturally turn to feelings of attraction
Critics: not much empirical support
