Gender development

Biological approach

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Specification

Biological influences on gender

The role of hormonesand genes in gender

development

Evolutionary explanations

of gender roles

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The relationship between sex and gender

• The biological approach suggests there is no distinction between sex & gender.

- biological sex creates gendered behaviour

The role of hormones and genesin gender

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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 – genesStep 2 – hormonesStep 3 – brain differences

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Biological differences between males & females (con)

• Complexity of this issue is demonstrated by the recent public gender testing of the athlete Caster Semenya

A boy or a girl?

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)

Male developmentMale development

XY

Male developmentMale developmentSRY 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

Female developmentFemale developmentThe absence of male hormone will result in the development of the Mullerian system into female sex organs

Between 8-24 weeksBetween 8-24 weeks: Male foetuses are exposed to higher levels of testosterone than female foetuses.

From 24 weeks until birthFrom 24 weeks until birth:

gonadal hormones are low in both sexes

The first 6 months of lifeThe first 6 months of life:

testosterone is higher in boys than girls

Action of testosterone on the brainAction of testosterone on the brain

Men and women produce the same Men and women produce the same hormones but in different quantity.hormones but in different quantity.

Oestrogen Progesterone

TestosteroneOestrogen Progesterone

Testosterone

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

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

PubertyAfter 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.

How does testosterone influence How does testosterone influence behaviour?behaviour?

Testosterone Aggressive behaviour

High sex drive

Poor language development

What evidence is there to support these statements?

How do oestrogen and How do oestrogen and progesterone affect behaviour?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

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From biological differences to gendered behaviour

• There are three sources of evidence to assess possible links between biological & behavioural differences:

1. Animal research2. Case studies of atypical individuals3. Correlational studies of the normal

population

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.

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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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