The role of chromosomes and hormones Flashcards
What is the role of chromosomes?
Chromosomes made from DNA
- Genes: short sections of DNA
- Genes determine characteristics
- 46 chromosomes in a human arranged into 23 pairs
- 23rd pair determines biological sex
- Chromosomal structure for females is XX
- Chromosomal structure for males is XY
How do chromosomes and hormones work inside the body?
- All normal eggs produced from an ovary have an X chromosome
- Sperm carries an X or Y chromosome
- Baby’s sex determined by the sperm that fertilizes the egg
- Baby will be female if the sperm carries an X chromosome
- Y chromosome carried a gene called the ‘Sex determining region Y’ (SRY)
- SRY causes testes to develop in an XY embryo
- Testes produce androgens (male sex hormones)
What is the role of hormones?
- Gender development comes from the influence of hormones
- Hormones influence brain development in the womb
- Hormones cause the development of reproductive organs
- A burst of hormonal activity causes puberty
- Males and females produce a lot of the same hormones but in different amounts
- In males, there’s lots of hormones called androgens
- Testosterone is a type of androgen
What is testosterone and what does it do?
- Male hormone
- Present in females in small amounts
- Controls the development of the male sex organs in the womb
- If a male produced none in the womb, no male sex organs will develop
- If a female produced a lot in the womb, make sex organs will develop
- High levels are linked to aggression which is adaptive
What is oestrogen and what does it do?
- Female hormone
- Determines female sexual characteristics and menstruation
- Causes physical changes
- Causes heightened emotions and irritability during menstruation
- Called premenstrual tension (PMT)
- Premenstrual stress has been used as a defense in criminal cases
- Some research disputes PMT as a medical condition
What is oxytocin and what does it do?
- Women produce this in larger amounts than men
- Particularly higher level after giving birth
- Stimulates lactation
- Reduces the stress hormone cortisol
- Called the ‘love hormone’
- Released in huge amounts during labor and childbirth
- Helps mothers love and bond with their babies
- Men produce a lot less than women
- Men produce it during kissing and sex
What are the strengths of testosterone?
Evidence supports the role of sex hormones even in older males
What study supported the roles?
Wang et al: male hypogonadism is caused by the testes failing to produce normal levels of testosterone
- 227 hypogonadal men given testosterone therapy for 180 days
- Monitored body shape, muscle strength, sexual function and libido
- Sexual function, libido, mood and muscle strength increased
- Testosterone has direct influence on male sexual arousal and physical development
What are the limitations of testosterone?
O’connor et al: double blind placebo study
- increased testosterone in healthy going men
- No increase in amount of sex or sex drives
- No change in aggression or anger
- Additional testosterone has no effect on sexual or aggressive behavior
What is a limitation of chromosomes and hormones?
Biological accounts ignore the role of social factors in gender related behaviors
How is the ignorance of biological accounts a limitation?
Hofstede et al: gender roles are cultural not biological
- Individualist cultures gender to be more masculine
- Social factors may be important in shaping gender behavior and attitudes
What’s another limitation of chromosomes and hormones?
Biological explanations are reductionist
- Doesn’t account for cognitive explanations such as schemas
- Psychodynamic approach would consider childhood experiences and early experiences
