Lecture 9

Question 1

Sex versus gender

Answer 1

SEX refers to the biological sex

GENDER refers to the psychological sex

Question 2

Factors influencing gender identity:

Answer 2

1) biological factors (genes, hormone exposure)
2) environmental factors (society, cultural and parental)
3) the interaction between the two

Question 3

Can Gender Be Assigned?

Answer 3

David Reimer had a botched circumcision but was one of two male twins

It was decided to remove his testicles and give E then raise him as female

Despite this Brenda never fit in, felt male

He was XY and so was exposed to androgens in development

When he found out what had happened he transitioned and considered himself male

Eventually, he killed himself. This should not have happened

Question 4

Gender Dysphoria

Answer 4

XX or XY chromosomes
-Gender is opposite biological sex

DSM 5 Diagnostic criteria

• A marked incongruence between one’s experienced/expressed gender and primary and/or secondary sex characteristics
• A strong desire to be rid of one’s primary and/or secondary sex characteristics
• A strong desire for the primary and/or secondary sex characteristics of the other gender
• A strong desire to be of the other gender
• A strong desire to be treated as the other gender
• A strong conviction that one has the typical feelings and reactions of the other gender

Change from DSM-IV
NO LONGER CALLED A DISORDER

Question 5

Symptoms of gender dysmorphia

Answer 5

• Belief that they will grow up to be the opposite sex
• Expressed desire to be the opposite sex
• Disgust with their own genitalia
• Withdrawal, isolation, depression
• Not due to a physically intersex condition

Question 6

Old vs new treatment of gender dysmorphia

Answer 6

Traditionally:
Thought to be entirely a disorder of the mind
Attempted to treat this through psychotherapy
Now recognized that there may be biological basis: psychological intervention is ineffective

Question 7

Combination of causes for gender dysmorphia

Answer 7

Prenatal hormonal imbalances

Genetic abnormalities

Defects in normal human bonding - much greater chance of having experienced child abuse
No strong bond with parent

Question 8

Society doesn’t like continuum….

Answer 8

-Societal constraints: only universally accepting of male and female as gender identities.
-Confronted by discrimination or harassment regularly
-Don’t mess with status quo
-Transgender individuals now protected under the Human Rights Act under the grounds of sex – as of 2017
-Quebec and other provinces following suit
(actually QC did it before, 2016)

Question 9

2D:4D story – physical measure for in utero androgens

Answer 9

• Men typically have longer ring than index fingers
• Females have similar index and ring fingers, or longer index finger
• Ratio of 2D:4D measure of in utero androgen exposure, androgen exposure is negatively correlated with ratio (males have a smaller ratio)

-Serves as a pretty reliable measure of early androgen exposure

Question 10

When we want to research sex-related variations in the brain:

Answer 10

We are interested in effect of testosterone in determining sex differences
Cognition, behaviour, orientation, identity

Biological mechanism for maleness

Contrast to traditional perspective: gender is based on nurture how a child is raised

Difficult – accurate studies in humans so many in animals
Examine people with CAH, CAI, or mothers treated with androgens

We wind up using either animals or rare human conditions as we cannot expose humans to androgens

Melissa Hines did this

Question 11

Hormones and play study

Answer 11

Male–typical play

• Rough and tumble
• Outdoors
• Cars

Female–typical play

• House, crafts
• Indoors
• Dolls

Subjects had

Congenital adrenal hyperplasia, maternal androgen admin and naturally higher maternal androgens

Naturally higher maternal androgens
Sometimes assessed in mothers during pregnancy if there is reason to do so, if not also use digit ratio

Androgen exposure was correlated by Hines with male typical behaviour in females

Question 12

Hormones and play study resultd

Answer 12

Female typical play

• Typical girls do lots of female typical play
• CAH girls did much less of it but still more than CAH boys and typical boys

Male typical play

• Girls with CAH do more than typical girls
• Less than boys with CAH and typical boys

Using the Preschool Activity Inventory which measures sex-typed childhood activities (is a more general measure and takes into account HOW the children’s played e.g. using a doll in a male way)

You see a magnification of the results. CAH females no different from CAH boys and normal boys on the PSAI and far higher than normal girls.

Question 13

Play in primates

Answer 13

No socializing role
Give an array of toys
Females choose female typical toys
Males choose male ones
Teases apart nurture and nature
Probably there is a biological drive for this

Question 14

Sex differences in other activities

Answer 14

Targeting, fine motor, spatial ability and aggression
Higher in males

Verbal fluency and empathy
Higher in Females

Male preference for vehicles and rough and tumble

Males prefer Prefer spatial movement?
Sex difference in primary visual cortex

Toy preference reflects underlying basic characteristic of stimuli

Question 15

Sex differences in brain development

Answer 15

Testosterone exposure masculinizes the brain
Rodents and monkeys: castration and hormone administration

Males have larger brains, females deeper gyri/larger sulci
Women thicker cortex

Testosterone enlarges sexually dimorphic brain regions

Medial hypothalamus, bed nucleus of stria terminalis (BNST), and amygdala

Some changes linked to gendered behaviour
Amygdala in rough and tumble play

Question 16

Hormones and Gender Identity

Answer 16

Pubertal hormones activate what was organized early in life

Act in brain areas organized in development

Females with CAH have identify as male more often

CAIS almost always identify as female even though XY

Klinefelter’s reports higher incidence of gender ambiguity and transgenderism

Could be that changes in androgens contributes to changes in gender

Question 17

Neurobiological differences in gender dysphoria Hypotheses

Answer 17

Major testosterone induced sex difference in rats brains
SDN of MPOA

Decided to examine humans on: post-mortem examination of the interstial nucleus of the anterior hypothalamus (INAH) does it differ in:

sexes
Male to female trans
Trans individuals?
Effect of adult changes in gonadal hormones?

Size based on number of neurons AND number of synapses is different with increased androgens

Question 18

Neurobiological differences in gender dysphoria (results)

Answer 18

Female gender consistently lower volume and neurons than male in INAH

• Male to female trans – smaller than men regardless of hormone replacement treatment
• Female to male trans in range of biological men

Adult hormone makes no difference

Some evidence this region is larger in hetero than homosexual men
Inconsistent results

Castrated males (had prostate cancer so removed) later in life had no androgens but still no difference in INAH which points to an early organizational effect

Post menopaused women’s INAH does not change size either

Question 19

Getting up to date on transgender differences pre gender affirming hormones

Answer 19

Are MtF individuals more like CF (and differ from CM), and vice versa
-Prior to hormone therapy use

Cognitive tasks:
-MtF perform better on verbal tasks than CM, FtM perform worse than CF

-Conceptual style more similar to indentified gender too MtF perform similarly to CM on spatial tasks

-Brain structure:
Cortical thickness, total grey matter, corpus callosum shape and resting state functional activity all more similar to identified gender
Some discrepancy here

So overall there are consistent differences

Some difference between MtF and CM, and FtM and CF
Not always - sit in between the two biological sexes on some measures?

Could they be somewhere in the middle on a spectrum?

Struggle with sex as continuum in our society
Societies with less discrete sex categories less difficulty with trans individuals

Question 20

When research gets it wrong….

BAD research on sex and gender

Answer 20

Research from a looong time ago
-Is there a link between androgens and masculine behaviour in CAH?
YES – but unclear back then

-Evidence that tomboy behaviour in CAH females linked to androgens
Froukje and Slijper think not…..

-Develop their own test of “girlishness” and compare CAH to childhood diabetes
Also looked at parental confidence of gender

Sophia task assesses girl and boy –ishness
-See consistently lower scores in boys and higher in females

Then compare this to health statuuses including CAH, diabetes, generically sick and bother/sister having CAH

See highest scores in healthy girls
-All sick children scored closer to neutral
-Did note that CAH females particularly low
(On sophia task)

They examined the effect t in females with salt-wasting CAH

Saw that CAH with salt-wasting had highest masculinity
Effect driven by this subset of CAH

Salt wasting because less aldosterone
-More severe illness than CAH without this

The concluded that THE SEVERITY of illness causes more masculinize behaviour

Also saw relation between parental sex confusion at birth and masculinization on Sophia

Parental uncertainty about gender masculinizes behaviour (could be intersex)

Question 21

Issue with Conclusions of the Sophia study

Answer 21

Salt wasting suggests more complete lack of 17B-hydroxylase
Suggests higher levels of androgen production

This is a confound – can explain BOTH of conclusions
More androgens would mean more masculinized behaviour
Also masculinize genitalia more, causing parental concern

Sophia task not validated against other measures
Boys and girls differed, but does it measuring same thing as other tests?
Rely heavily on a few responses that are not validated

Confirmation bias in action!!
Skepticism is key

Question 22

Hormones and Sexual Orientation

Answer 22

Pubertal hormones activate what was organized early in life. This can cause an issue if everyone around you is interested in the opposite sex and you are not.

Even if adjust hormone in childhood and adulthood see differences

Females with CAH identify as male more often

Higher incidence of homosexuality as well

CAIS almost always identify as female with sexual interest in males. Sexual orientation here is inline with gender, not sex.

Question 23

Hormones and Sexual Orientation

Kinsey

Answer 23

Evidence for sexuality existing along a continuum too

Kinsey was a biologist studying Gall Wasps, made to teach human sexuality
No scientific information so decided to work it out

Devoted remainder of career top studying sexual behaviour
-Sexuality does not seem binary – huge variation
-Homosexuality not as aberrant as expected
He may have based this off an extreme sample but the point stands

The Kinsey rereport and the Kinsey Institute

Question 24

Hormones and Sexual Orientation

Answer 24

Some 2D:4D studies suggest that larger ratio linked to male homosexuality (2D same as or larger than 4D)

• Less testosterone = larger ratio = increased homosexuality
• Results ambiguous

Birth order linked to sexual orientation

• Mother antibodies against T, activated more rapidly in later pregnancies
• Males later in birth order = increased homosexuality

Question 25

2D:4D and homosexuality

Answer 25

- Homosexual males larger ratio than heterosexual - Homosexual females smaller ratio than heterosexual In neither case were the 2D:4D ratios as extreme as they were in hetro men and women. Hence, it seems possible that homosexuals sit somewhere in the middle of a spectrum of gender

Question 26

Getting up to date on biological basis of homosexuality

Answer 26

Quick look at updates in brain changes associated with homosexuality Red = interstitial nucleus, similar in hetero men and homo women -It is larger in hetro men and homo women Brown = hemisphere size, asymmetrical in hetero men and homo women -More equal in homosexual men and hetrosexual women Green = olfactory regions, pheromones activate differently - Larger in hetrosexual women and gay men - Could mean that smell and pheromones' affect them differently Blue = right amygdala more connected in hetero men and homo women, leftt amygdala more connected in hetero women and homo men - Likely a target for sex dependent behavior. - Larger in childhood = more rough play in childhood - Larger in adult = Changes in sexual behavior Yellow = anterior commissure, women and homo men larger than hetero men

Question 27

Development of physical sex, psychological sex and sexual orientation across development

Answer 27

- Organization can alter physiology and psychology - Mediated by hormones - There are many ways this can be altered - These may contribute to gender and sexuality - It is possible hormone levels change and alter psychological stuff even AFTER they already caused physiological changes - This could result in a masculinized brain that does not match one's biological sex

Question 28

Sex-related variation in human behavior and the brain (basics)

Answer 28

● Prenatal testosterone levels differ between sexes as early as week 8 of gestation ● Differences in hormone levels seem to affect sex-typical childhood behaviors (which were recently believed to result only from sociocultural influences) ● Brain structures responsible for these hormone-induced behavioral outcomes include the hippocampus and amygdala, in addition to interhemispheric connectivity and cortical areas involved in visual processing

Question 29

Human sexual differentiation

Answer 29

● Growing evidence that prenatal androgen exposure influences other things (aside from sex-typical play) such as sexual orientation, gender identity, personality characteristics, and moroe performance

Question 30

Toy Story

Answer 30

● Traditional developmental psychological theories suggested that children acquire sex-typical behavior through social leanring and cognitive developmental processes that lead to gender identification and valueing od behaviors associated with one’s gender ○ We now have evidence suggesting that prenatal testosterone also plays a role

Question 31

Hormones and Sexual Differentiation

Answer 31

● Girls exposed to unusually high levels of androgens prenatally (typically due to CAH) show increased male-typical play and decreased female-typical play ● Children whose mothers took androgenic progestins during pregnancy show increased male-typical play whereas children whose mothers took anti-androgenic progestins show decreased male-typical play

Question 32

Addressing the Counterarguments about hormonally changed behavior

Answer 32

● Was once suggested that the abnormal external genitalia of CAH girls masculinizes their behavior rather than the action of androgens in the brain ○ However more recent studies have shown that this is not the case ● It’s unlikely that socialization accounts for the relation between prenatal hormones and postnatal behavior ● Studies of non-human primates have found sex-typed toy preferences similar to those gound in humans

Question 33

A new perspective on toys

Answer 33

● Sex-typed color preferences do not seem to underlie sex-typed toy preferences ● Suggested that boys like toys that can be moved in space and increased androgen exposure may play a role in this by altering the visual system

Question 34

Early hormonal influences on sexual orientation and gender identity

Answer 34

● CAH women show reduced heterosexual orientation ● Normal variability in prenatal testosterone levels has not been related to sexual orientation ● 2D:4D ratio: the ratio of the second finger of the hand to the length of the fourth finger ○ Higher in females than males ○ Thought to reflect the amounts of prenatal androgen exposure ● Study with 200,000 individuals who measured their 2D:4D and reported their sexual orientation online showed that 2D:4D related as predicted to sexual orientation in males, but not females ○ Another study found the opposite ○ Finger ratios are probably a weak correlate of androgen exposure

Question 35

Early hormone influences on personality, cognition, and motor performance (in sexes)

Answer 35

● Empathy is higher in females ● Physical aggression is higher in males ● Females with CAH show reduced empathy ● Testosterone measured in amniotic fluid relates negatively to empathy in both sexes ● One study showed that CAH females are more accurate at throwing balls and darts at targets ○ Result was not accounted for by increased muscle strength ● Results concerning differences in cognitive abilities are mixed

Question 36

Sex-related psychiatric disorders

Answer 36

● Testosterone has been suggested to contribute to ASD, OCD, and Tourette’s syndrome

Question 37

Sex differences in the brain

Answer 37

● Total brain volume (as with body size) is larger in males than females ● Males have larger amygdala, females have larger hippocampus ● Females have greater cortical thickness in many regions ● Females have increased gyrification in frontal and parietal cortex, and perhaps more efficient use of white matter ○ Perhaps to compensate for lack of volume ● Third interstitial nucleus of the anterior hypothalamus (INAH-3) is larger in males than females ○ Homologous to SDN-POA in rodents ● Patterns of cerebral asymmetry have been linked to sexual orientation in both men and women ● Existence of neural differences does not prove that hormonal exposure caused the difference ○ Brain is plastic and changes with experience

Question 38

Summary of article 1

Answer 38

Concluding Remarks ● Many sex differences have been described in the human brain but onluy a subset have been related to behavioral sex differences and fewer to the early hormone environment ● Toys have non-obvious properties that make them more or less attractive to an androgen-exposed brain

Question 39

Background of old, bad study (discredited)

Answer 39

Study Background ● Participants in study ○ Healthy controls ○ CAH ○ Diabetes ○ Siblings of CAH children ● Given the Sophia test in which they were asked to draw a person to answer the question: if I could have chosen between being born a girl or a boy I would have chosen…” ● Parents were interviewed about psychosexual and psychosocial development ● Other medical data were also collected

Question 40

Results/conclusions of old bad study

Answer 40

Results/Conclusions ● Girls with CAH or diabetes scored more “on the boyish side” of the Sophia test ○ The effect on gender role behavior is not necessarily explained by hormonal action alone; being sick plays a role ● CAH girls scored “on the more boyish side” than diabetic girls ○ Specific CAH effect is fully accounted for by the group of girls with the salt-loss variant of CAH ● Degree of virilization does not correlate with gender score ● CAH and diabetic boys score “on the more girlish” side of the Sophia test ● Chronically ill children seem to have more problems with aggressive behavior than healthy children ○ Diabetic girls differ from control girls in their appreciation of fighting ○ CAH boys and diabetic boys differ in their appreciation for “romping with father” ● Study suggests that activation of aggression is related to sickness rather than prenatal hormonal factors ● The hypothesis that behavior is masculinized by exposure to androgen hormones cannot be supported by this study ● Psychosocial factors such as the child being sick, and parents’ doubts about the sex of the child seem to havre more influence on gender role behavior than does androgenic hormone action

Question 41

What we knew before article 3 about sex behavior

Answer 41

In human females, sexual responsiveness does not have the sharp relationship to folliculogenesis and to the functioning of the corpus luteum in the ovary that us does in most lower mammals ● In males of several species including humans, sexual activity persists following castration ○ Corresponding phenomenon in females is encountered rarely in females below the primates ● Female guinea pigs: the beginning of the preovulatory growth phase of the Graafian follicle coincides closely with the beginning of being in heat ● Progesterone’s synergic action in combination with estrogens bring latent mating behavior to expression ○ Has been demonstrated in numerous mammalian species ● Luteotrophin is responsible for the production of progesterone

Question 42

Importance of Soma

Answer 42

● The nature of latent behavior brought to expression by gonadal hormones depends largely on the character of the soma or substrate on which the hormones act ● Substrate assumed to be neural

Question 43

Factors influencing character of soma

Answer 43

● Reports of the effects of thyroid hormone on the vigor of sexual behavior in the male are very contradictory ● Sexual behavior is not inherited as a unitary trait ● Psychological factors might have a role in the determination of the character of the soma ● Males raised in isolation displayed an inability to mount a female properly ○ Guinea pigs need contact with other animals for the maturation of normal behavior

Question 44

Special influence of early hormonal factors

Answer 44

● Female guinea pigs given testosterone prenatally had ovaries and 2 sets of duct systems ○ Also displayed male-typical behaviors ○ Lost ability to come into heat ● During the fetal period the hormones have an organizing action on the neural tissues destined to mediate mating behavior in adulthood ● During the fetal period, gonadal hormones influence direction of differentiation and during adulthood, they stimulate dunctioning ● In females and castrated males, development of the Mullerian system and regression of the Wolffian system occurs ● Males castrated earlier in life and given estradiol and progesterone injections displayed more female-typical behaviors than males castrated later ○ Castration after day 10 did not promote the development of female-typical behaviors

Question 45

Extension to sex-related behavior

Answer 45

● Study with monkeys ○ Female pseudohermaphrodites: a number of social behaviors known to be sexually dimorphic and without any immediate instrumentality relative to mating were influenced in the masculine direction

Question 46

Implications of paper 3

Answer 46

● The principles of hormonal action in affecting sexual differentiation of the developing brain provide a model to which we can look for a reexamination of psychosexual incongruencies ● Testosterone does not induce masculinization of the adult female guinea pig while it’s pregnant Summary ● Hormones act according to principles which appear to be identical with those operative during the differentiation of the genital tracts, and they affect a corresponding differentiation or organization of neural tissues ● Early hormonal action is responsible for sex-related behavior which is part of the masculinity or femininity of an individual but which is not related directly to the reproductive process