Chapter 4.5 and 4.6 Flashcards
What are the 2 key hormonal effects influencing sex differences? (behavior in general)
Organizational effects: occur early in development, shaping the structure of neural circuits
Activational effects: Occur later in life, triggering or modulating behaviors
Behavioral endocrinologists work to…
Distinguish hormonal effects from environmental influences
Name 4 examples to show how organizational and activational effects can interact (2x2 Matrix of hormonal effects on behavior)
Organizational/Activational: Rodents sexual behavior
Activational: Rhesus monkeys yawming, electric discharge in elect. fish
Organizational: Primate rough-and-tumble play behavior
Neither: Human gender role learning
What is medroxyproesterone acetate (MPA)?
A substance that affects fetal development
What factors influence/shape gender identity?
Biological factors
Environmental and cultural factors
How are medical/ethical decisions made when faced with gender ambiguity at birth?
Physicians rely on case studies due to the rarity of ambiguous genitalia.
Decisions are often made under emotional and time pressure in the maternity ward.
Treatment approaches are influenced by historical, medical, and ethical considerations
What are 3 different treatment approaches to ambiguous genitalia?
- Match external genitalia to genetic sex
- Perform surgical and endocrine treatments to align genitalia with XX or XY chromosomes
3.
What is assumed if a decision is based on genital appearance (ex: If genitalia appear more male/female, surgery aligns with that appearance.)
It assumes early biological factors are less important than rearing environment.
–>the way a person looks will influence how others will act and interact with this person
What did Dr. John Money think about the significance of gender identity?
She believed gender identity is neutral at birth and is shaped by upbringing.
“If you treat him as a girl, he will think he is a girl”
In the John/Joan case study, what was found at the initial and the 25 year follow-up?
Initial: Joan seemed to have successfully adapted to female identity, although displaying tomboyish behaviors
25 years: Joan transitioned back to male in adolescence, reported several mental distress and a feeling of being a male. Eventually underwent reconstructive surgery and lived as a man
*both him and his brother died by suicide
What did the John/Joan case study show about gender identity?
Suggested biological factors strongly influence gender identity
Summarize Diamond & Sigmundson’s review on sex-reassignment at birth (1997).
The paper follows the case of an XY individual whose penis was accidentally ablated during infancy.
The individual was subsequently
raised as a female. Initially, it was reported that the individual developed as a normally functioning female.
However, later in life, the individual rejected the female gender assignment, transitioned to living as a male during puberty, and has successfully lived as a male since then
What is not a key postulate of Diamond & Sigmundson’s review on sex-reassignment at birth (1997)?
a. Gender Identity is Innate
b. Importance of biological factors
c. Environment shapes gender identity
d. Ethical considerations in sex reassignment
c. Environment shapes gender identity
a. individual identified as
male
b. challeges the notion that gender can be entirely reassigned through social and medical interventions
c. need for informed consent + consideration of the individual’s future
What is the ISNA (1993-2008) and what does it recommend?
-Intersex Society of North America
- Recommends to assign gender based on likely future identity, but avoid irreversible surgery in infancy
- Recognizes the complexity of genetic, hormonal and environmental influences on gender identity
- Peer support is crucial (+ parental consultation with psychologists and social workers)
During early gestation, how does hormonal exposure [sex steroid hormones] shapes brain and behavior?
High levels–> Masculinization and Defeminization
Low levels–> Feminization and demasculinization
*Early hormone exposure has lasting effects on cognitive and behavioral development
What is the Concealment-Centered model (traditional medical model) and how does it view gender identity?
- Intersex= pathological condition, requiring immediate medical intervention
- Gender is determined by nurture
- Encourages secrecy about the condition
- Prioritizes parental distress and societal norms
When does human sexual differentiation occur?
Early in gestation, in the end of the first trimester and early second trimester
What characterizes individuals with Congenital Adrenal Hyperplasia (CAH)?
Excess androgen exposure, leading to a masculinization of behavior
Non production of corticosteroids leads brain to signal more adrenal gland activity. Then, glands become bigger and still can’t produce corticosteroids, but produce sex hormones in excess
Females: Enhanced visuospatial abilities due to early androgen exposure, though findings are inconsistent.
A female with CAH may exhibit male-typical behaviors, but is this due to early androgen exposure or parental reinforcement of
gender-nonconforming behavior
What characterizes individuals with 5α-Reductase Deficiency?
Defective/absent 5α-Reductase (responsible for converting testosterone into dehydrotestosterone [development of male genitalia in male foetus]), leading to ambiguous genitalia and delayed masculinization
What characterizes individuals with Complete or Partial Androgen Insensitivity Syndrome?
Resistance to androgens–>feminization despite XY genotype (ex: video “My experience with AIS”)
Maternal hormone treatments during pregnancy can have atrocious effects on babies. Name 3 possible effects.
- Diethylstilbestrol (DES): Synthetic estrogen linked to reproductive and behavioral effects.
- Medroxyprogesterone Acetate (MPA): Progestin used to prevent miscarriage, may affect fetal development.
- Turner Syndrome (XO genotype): Typical hormone exposure until childhood; puberty onset may be disrupted
What is not an advantage of animal research?
a. Genetically identical subjects from inbred strains.
b. Controlled timing, dose, and exposure to hormones.
c. Ethical considerations
d. Standardized testing conditions
e. These are all advantages of animal research
c. Ethical considerations
Name 4 limitations of human studies
- Case studies vary in severity and timing of disorders.
- Hormone treatments differ in dose, type, and administration period.
- Confounding factors: Medical conditions prompting hormone treatment (e.g., toxemia) and Parental expectations influencing behavior
- Behavioral variability: more variations exists within sexes…and considerable overlap between
What could be more informative than studying broad sex categories?
Studying individuals
