ROLE OF CHROMOSOMES AND HORMONES IN SEX AND GENDER

What is the difference between men and women’s chromosomes

Women have XX chromosomes, men have XY chromosomes

What gene does the Y chromosome carry

The sex determining region Y (SRY

What does the sex determining region Y gene do

It starts to promote the production of testosterone and other androgens

What are androgens

Male sex hormones

What do androgens cause males to develop

Testes and a penis rather than ovaries and a uterus

What do androgens do to a males brain

They cause the male’s brain to develop differently to the females

What is an example of a difference between men and womens brains due to androgens in the male brain

For example there are differences in the hypothalamus of males and females, with the sexual dimorphic nucleus being larger in males

What else can cause men and women to behave differently

The differences in secretion of hormones

Which hormone is associated with males type behaviours

Testosterone

What kind of ‘male’ behaviours is testosterone associated with

Aggression and competitiveness as well as a more ‘masculine personality’ with personality attributes such as being individualistic and acting as a leader

What is oestrogen

A female sex hormone that determines female sex characteristics and is involved in controlling the menstrual cycle

What behaviours is oestrogen associated with

Sensitivity and cooperation

What is oxytocin referred to as

The love hormone as it’s involved in bonding and released during hugging, kissing and sex

Why do females produce more oxytocin than men

Because it also plays a role in childbirth and breastfeeding

TRICKER ET AL

Gave 43 males weekly injection of testosterone or a placebo

No significant differences found after 10weeks

Suggests sex hormones didn’t have consistent effect on gender related behaviours

Suggests hormones may not have a straightforward effect on gender related behaviour as increasing testosterone didn’t consistently increase aggression.

Indicates that while hormones influence physical sex characteristics, they alone don’t determine gendered behaviours highlighting that sex & gender are shaped by multiple factors beyond biology like socialisation

Cultural differences - third genders

In some cultures, there are third genders applied to individuals who fall outside of the strict classification of ‘man’ or ‘woman’

In India, Pakistan and Bangladesh there is a 3rd gender applied for people who are transgender

Known as ‘hijras’

Shows gender is strongly shaped by cultural and social influences

Highlighting that gender identity is not fixed or purely biological but depends on how societies define, recognise + value different gender identities

Cultural acceptance plays an important role in allowing individuals to understand + express their gender identity

Cultural acceptance plays important role in allowing individuals to understand and express their gender identity

Imperato - McGinley et al

Conducted research on guevedoces in Dominican republic

These individuals were initially raised as girls due to a lack of male genitalia at birth; a condition caused by a deficiency of an enzyme involved in the development of male sex organs.

Was discovered that at puberty when a surge in testosterone occurred, the guevedoces underwent a natural transition to male characteristics including the growth of a penis

Shows that hormones are key in developing sex characteristics + gender as testosterone triggers physical changes + influences gender identity

Demonstrates that while chromosomes determine genetic sex, its the presence & action of hormones that shape how sex is expressed in body & behaviour