2. Hormones and Chromosomes

• Role of chromosomes

  • Made from DNA
  • Genes determine characteristics
  • 46 chromosomes, 23 pairs, last pair determines biological sex
  • Males - XY
  • Females - XX
  • Egg cells have an X whilst sperm cells contain X or Y
  • Baby's sex is determined by the sperm that fertilises the egg cell
  • X for female and Y for male
  • Y chromosome carries a gene called SRY which causes testes to develop an XY embryo - produces androgens (male sex hormones)
• Role of hormones

  • Influences gender development
  • Prenatally in the womb, hormones act upon brain development and cause development of the reproductive organs
  • At puberty, a burst of hormonal activity triggers the development of secondary sexual characteristics
  • Males and females produce many of the same hormones but in different concentrations
• Testosterone

  • Male hormone present in small quantities in women
  • Controls the development of male sex organs during foetal development - no testosterone means no male sex organs
  • If a genetic female produces high levels of testosterone during this time, male sex organs may appear
  • High levels linked to aggression
  • Allows males to compete for fertile females
• Oestrogen

  • Female hormone that determines female sexual characteristics and menstruation
  • Causes heightened emotions in women and irritability
  • Referred to as PMT or PMS
  • In extreme cases, PMS has been used successfully as a defence in cases of shoplifting and murder
• Oxytocin

  • 'Love hormone'
  • Women typically produce more than men particularly as a result of giving birth
  • Stimulates lactation for breastfeeding
  • Reduces stress hormone of cortisol and facilitates bonding
  • Released in massive quantities during labour
  • Fuels stereotype that men are less interested in intimacy
• AO3 - Strength of research support

  • Money and Ehrhardt - the case of David Reimer. Strong male identity despite being raised as a girl
  • Van Goozen et al. - studied transgender individuals undergoing hormone treatment and found that transgender women showed decreases in aggression whilst transgender men showed the opposite
  • Highlights the influences of biological influences in gender development
• AO3 - Counterpoint of research support

  • Both studies focus on unique individuals making generalisation limited
  • Contradictory research of O' Connor - increased testosterone levels in healthy young men and found no differences in sex drive or aggression levels
  • Questions the determinism of biology and suggests an interactionist stance is more appropriate as environment may be an influencing factor on gender development
• AO3 - Limitation of biology being reductionist

  • Reducing gender to the level of hormones and chromosomes underplays alternative explanations
  • Cognitive approach - outlines the approach of schema which creates gender stereotypes for girls and boys such as what toys they play with which develops into their identity
  • Psychodynamic approach - acknowledges maturation as a factor influencing gender development but also recognises the importance of childhood experience eg. same-sex role models
  • Gender is more complex than biological influences - environment
• AO3 - Limitation of biological factors overlooking social factors in gender related behaviours

  • Hofstede et al. claims gender roles around the world are more a consequence of social norms than biology
  • Notions of masculinity and femininity have been equated to whether cultures are individualist or collectivist
  • Countries that place individual competition and independence above the needs of the community are more masculine (according to Hofstede)
  • US and UK being advanced capitalist societies value masculine traits over feminine
  • Challenges biological explanations of gender development