Biological Approach - Gender

• What are chromosomes


  Threadlike structures made up of protein and a single molecule of DNA. Each cell normally contains 23 pairs of chromosomes. XX= female XY=Male
• What do chromosomes do?

  They carry genomic information from cell to cell and determine our sex.
• How does a foetus become a boy of a girl?


  All normal eggs produced by an ovary have an X chromosome.

  The baby's sex is determined by the chromosome the male sperm carries that fertilises the egg.

  If the male sperm carries an X chromosome the baby will be a girl

  If the male sperm carried a Y chromosome the baby will be a boy.
• First 6-8 weeks of foetus development


  All foetuses have the same undeveloped sex organs (gonads)

  The original system can develop into both male or female sex organs. It is the presence or absence of a single gene ( SRY gene, Sex determining Region Y) which will dictate the future development of the foetus as a male/female.

  Everything develops as a female unless instructed otherwise.

  The Y chromosome contains instructions for the body to produce androgens (male sex hormones)

  These cause the embryo to develop along the 'male path'
• How does a foetus become a boy?

  SRY gene produces a protein : Testis Determining Factor (TDF). TDF influences the development of the gonads, they become testis.

  The testis produce testosterone. This triggers the development of external male organs i.e penis
• How does a foetus become a girl?


  The absence of male hormones will result in the development of the Mullerion system into female sex organs.
• What are hormones 


  They are chemical substances that act like messenger molecules in the body. Male hormones are called androgens.
• What do hormones do


  They help to control many body functions such as growth repair and reproduction. Control and regulate activity of particular cells e.g testosterone.
• Testosterone


  Produces prenatally and affects the development of the genitals.

  It impacts brain development prenatally and in childhood.

  Mothers exposed to testosterone with female babies were more likely to show tomboyish behaviours.

  Testosterone is responsible for facial hair and deepening of voices.

  Research suggests that testosterone has a link to aggressive behaviour.

  Van de Poll 1988 injected female rats with testosterone and found them to be more physically and sexually aggressive.
• Oestrogen 


  It's the female hormone that determines sexual characteristics and menstruation. Females don't need hormone to direct prenatal development of genitals. It plays a major role in promoting secondary sexual characteristics (breasts, menstrual cycle, widening of hips).

  Causes some women to experience pre-menstrual syndrome (PMS) which has been used as defence against crimes such as murder and shoplifting.
• Oxytocin


  The love hormone promotes feelings of bonding in men and women.

  Produces by the pituitary gland- evokes feelings of contempt and calmness. Released in childbirth. Helps flow of breastmilk in mother and with the feeling of being 'in love' with their baby. Oxytocin is also released during sexual activities.

  During stress, oxytocin dampens the fight or flight responses.

  In females the alternative tend and befriend response allows them to protect their young (tend) and form protective alliances (befriend).

  This doesn't happen in men.
• Evaluation - How does it ignore social factors


  Hofstede et al claims that gender roles around the world are much more a consequence of social norms than biology. Researchers equate notions of masculinity and femininity with whether whole cultures are individualistic or collectivist. Countries that place individual competition and independence above the needs of community are more masculine.

  Consequently, traditional masculine traits will be more highly valued within these societies. This suggests social factors may ultimately be more important in shaping gender behaviours and attitudes.
• Evaluation- Reductionist 


  Accounts that reduce gender to the level of chromosomes and hormones have been accused of ignoring or underplaying alternative explanations. The cognitive approach would draw attention to the influence of thought processes like schemas. Even though changes in thought processes come through maturation of the developing brain, they aren't adequately explained by biological models. In addition, the psychodynamic approach would acknowledge maturation as a factor but point to the importance of childhood experiences such as interaction within the family.
• Evaluation- Evidence to support the role of chromosomes on development.


  Case of David Reimer. In relation to sex hormones, James Dabbs et al found in a prison population that offenders with the highest levels of testosterone were more likely to have committed violent or sexually motivated crimes
• Evalutation - Contradictory evidence


  Effect of testosterone is less convincing.

  In a double blind placebo study Daryl O Connor et al increased testosterone levels in healthy young men. There were no significant increases in the interactional / non interactional components of sexual behaviour in p.p

  The men involved experienced no change in their aggression or anger levels during the investigation

  This suggests that additional testosterone may have no effect on sexual or aggressive behaviour