The document discusses the biological approach to gender development. It describes how biological factors like genes, hormones and brain differences influence whether a fetus develops as male or female. During development, testosterone exposure affects the formation of sex organs and later impacts behaviors by changing the brain. Studies on animals, intersex individuals and hormone correlations in humans provide some evidence linking biology to gendered behaviors, though methods have limitations. The complexity of influences on gender is exemplified by cases like Caster Semenya.

1. Gender development
Biological approach

2. 2
Specification
Biological
influences
on gender
The role of hormones
and genes in gender
development
Evolutionary
explanations
of gender roles

3. Sex and gender
• Sex: the anatomy of an individual's
reproductive system, and secondary sex
characteristics
• Gender: refers to either social roles based on
the sex of the person (gender role) or personal
identification of one's own gender based on
an internal awareness (gender identity).

4. • In some circumstances, an individual's
assigned sex and gender do not align, and the
person may be transgender,[1] or intersex.

5. 5
The relationship between sex and gender
• The biological approach suggests there is no
distinction between sex & gender.
- biological sex creates gendered behaviour

6. The role of hormones and genes
in gender

7. 7
Biological differences between males &
females
• What makes a baby a girl or a boy?
• It can be seen as a journey in 3 steps:
Step 1 – genes
Step 2 – hormones
Step 3 – brain differences

8. 8
Biological differences between males &
females (con)
• Complexity of this issue is demonstrated by
the recent public gender testing of the athlete
Caster Semenya

9. A boy or a girl?

10. In the first 6-8 weeks
All foetuses have the same undeveloped sex organs. The original
system can develop into both male or female sex organs. It is
the presence or absence of a single gene (SRY gene) which will
dictate the future development of the foetus as a male or a
female.
(Male)
(Female)

11. Male development
XY

12. Male development
SRY gene produces a protein :
Testis Determining Factor (TDF)
TDF influences the development
of the gonads, they become testis
The testis produce testosterone
Testosterone triggers the
development of external male
organs i.e. penis

13. Female development
The absence of male hormone will result in the
development of the Mullerian system into
female sex organs

15. Between 8-24 weeks: Male
foetuses are exposed to
higher levels of testosterone
than female foetuses.
From 24 weeks until birth:
gonadal hormones are low in
both sexes
The first 6 months of life:
testosterone is higher in boys
than girls

16. Action of testosterone on the brain

18. Men and women produce the same
hormones but in different quantity.
Oestrogen
Progesterone
Testosterone
Oestrogen
Progesterone
Testosterone

19. On average, men produce
between 4 and 10mg of the
hormone per day and overall
they have about 20 times more
testosterone than women.

21. It is difficult to measure the amount
of hormones because they are very
similar and the body sometimes
converts the one into the other
Testosterone
Progesterone
And… the body can convert one
hormone into another

22. Puberty
After around 10 years, the hypothalamus releases a
hormone which affects the anterior pituitary gland and
this causes the gonads to become active. They control
the development of secondary sexual characteristics.

23. How does testosterone influence
behaviour?
Testosterone Aggressive behaviour
High sex drive
Poor language development
What evidence is there to support these statements?

24. How do oestrogen and
progesterone affect behaviour?
Premenstrual syndrome
Myth or reality?
45 % of Attempted Suicides occurred
during the week preceding Menstruation
(Wallach and Rubin, 1968)
67% of Alcohol Drinking
Binges during PMS
North Carolina Prison Study 41 % of the inmate
assaults during PMS (Ellis& Austin, 1971)
PMS has been used as
a legal defence with
varying degree of
success

25. 25
From biological differences to gendered
behaviour
• There are three sources of evidence to
assess possible links between biological &
behavioural differences:
1. Animal research
2. Case studies of atypical individuals
3. Correlational studies of the normal
population

26. Animal Research
 Young ( 1966)
 Changed the sexual behaviour of both male and female rats
by manipulating the amount of male and female hormones
that the rats received during their early development.
 They displayed “reversed” sexual behaviour
 The effects were unchangeable.
 Young believed that the exposure had changed the sexually
dimorphic nucleus.
 The results have proven to be highly replicable.
 What does that mean for a study?

27. Case Studies
 Money & Erdhardt (1972)
 Studied a group of females who had received higher
than usual exposure to male hormones in utero.
 In comparison to their non-exposed sisters, mother’s
reported differences between the two groups.
 Exposed individuals played more masculine games,
had a higher IQ and greater career aspirations.
 Methods used were questionable (Holloway, 2002)

28. Case studies:
Androgen insensitivity syndrome
(Testicular feminization)
Androgen insensitivity syndrome (AIS) is when a person
who is genetically male (has one X and one Y
chromosome) is resistant to male hormones called
androgens. As a result, the person has some or all of
the physical characteristics of a woman, despite having
the genetic makeup of a man.

29. Population studies:
Deady et al (2006)
• Through the use of physiological markers
(physical characteristics that can be seen and
measured.
• Examined the relationship between gender
role orientation and testosterone in child-free
young women.
• P’s completed BEMs SRI scale and further
questionnaire.
• Established link between high levels of male
hormone and low desire for children.

30. 30
Support for Biological approach -
evaluation
• Evidence from biological studies has found some
support that behavioural differences may have their
origins in biology:
- Deady’s study found that women with high
testosterone levels tend to have lower scores on a
desire to have children rating scale
- Rommsayer’s study implies that lower levels of male
sex hormones may correlate with androgyny
- It explains the case of David Reimer

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