1. SPECIFICATION EXPLAINED
SPECFICATION CONTENT
SPECIFICATION EXPLAINED
THE ROLE OF HORMONES AND GENES IN GENDER DEVELOPMENT
Describe the role of both hormones and genes in gender development
Evaluate the role of both hormones and genes in gender development
EVOLUTIONARY EXPLANATIONS OF GENDER ROLES
Describe two or more aspects of gender role from an evolutionary perspective
Evaluate explanations of two or more aspects of gender role from an evolutionary perspective

2. Greetings, earthlings.
We have noticed that there are two sorts of human, women and men. How are they different?

3. What do you think these terms mean?
Sex
Gender
Gender-role stereotype

4. Gender terminology
Sex – biological characteristics of a person (genes/chromosomes; reproductive anatomy)
Male & female (?)
Gender – psychological or behavioural characteristics of a person relating to their sex (ways of thinking, feeling, acting)
Masculine & feminine (?)
Gender-role stereotypes – widely held beliefs about expected or appropriate ways of acting for men and women

5. Nature and nurture
The debate about whether variations in psychological & behavioural traits are caused by innate or environmental factors.
E.g. intelligence: if Jane is more intelligent than John, is that because she was born that way or because her environment & experiences made her that way?

6. How does the nature-nurture issue apply to gender development?
What might the different positions be?

7. Nature and nurture Nature Nurture Interactionism
Gender differences are caused by innate tendencies that are modified by environmental factors
Gender differences result from innate differences between female and male (genes, chromosomes, nervous system, hormones).
Gender differences result from the different experiences that females and males have as they develop (learning from family, peers, society)

8. Biological differences between the sexes

9. oestrogen

10. ‘What did you have?’
An embryo has 23 pairs of chromosomes, each pair made up of one from the ovum and one from the sperm.
The 23rd pair determines the sex. If it inherits the X chromosome from both parents it will be a female, if it inherits one X and one Y then it will be male.

11. Biological Theory of Sex and Gender
Chromosomes
female XX
male XY

12. HOWEVER ... (A02) Sometimes it’s not that straight forward!
Some people are born with XXY, XYY or XXX chromosomes
They often still live as either ‘men’ or ‘women’, so what does that tell us about taking chromosomes as ‘being the whole story’ to what gender IS?

13. Biological Theory of Sex and Gender
Chromosomes
Gonads

14. Between weeks after conception the gene on the 23rd chromosome instructs the gonads to release hormones.
Instructions to:
Male - release testosterone
Female - release no testosterone

15. At about 6 weeks, a gene on the Y chromosome, the SRY gene (Sex-determining region Y), causes the gonads of the embryo to develop as testes
If the embryo has no Y chromosome, it will not have the SRY gene. Without the SRY gene, the gonads will develop as ovaries

16. 4-7 weeks
9 weeks
12 weeks

17. Gonads Hormones Chromosomes Biological Theory of Sex and Gender
androgens
(testosterone)
oestrogen

18. Male development The testis produce testosterone
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

19. The sex hormones also influence the way that the brain develops
The production of androgens in males leads to the development of the penis and the scrotum.
The production of oestrogen in females leads to the development of the uterus and the vagina.
Both sexes produce both hormones, but in different amounts. Males have 20 times more testosterone than females.
The sex hormones also influence
the way that the brain develops

20. Androgen insensitivity syndrome (Testicular feminization)
HOWEVER ... (A02)
Androgen insensitivity syndrome (Testicular feminization)
Androgen insensitivity syndrome (AIS) is when a person who is genetically male (XY) is resistant to the male hormones (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.

21. 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.

22. testosterone leads to...
oestrogen lead to...
and stops this...

23. Transsexuals given hormones as part of sex change therapy
The theory goes that hormones also affect behaviour and cognition.
Males
better visuo-spatial skills
better mathmatical skills
more physically agressive
Females
better verbal skills
better perceptual speed
better manual dexterity
Transsexuals given hormones as part of sex change therapy
Female to male transsexuals
given testosterone =
Female to male transsexuals
given testosterone =
more 'male' behaviour traits
fewer 'female' behaviour traits
more 'female' behaviour traits
fewer 'male' behaviour traits

24. Brain differences Swaab & Fliers –
Found evidence of an area of the brain which they called ‘the sexually dimorhpic nucleus’.  It’s located in the hypothalamus and believed to be related to sexual behavior in animals
They found that the volume of the SDN was 2.5 times larger in men.
Generally accepted view is that these differences arise from the pre-natal action of sex hormones.

25. Degree of lateralisation
Shaywitz and Shaywitz (1995)
Left hemisphere - controls speech and language
Corpus Callosum
(communication line)
Right hemisphere - controls spatial skills

26. Evaluation of Bio Approach
This approach does not take into account social factors such as social norms; as such...
... It is determinist; we have no free will in how we ‘do gender’ – it is dictated by our biology
Behaviours could be learnt through social learning (as we will see later).
‘Self-fulfilling prophecy’ could explain the difference in behaviour between genders.