The role of chromosomes and hormones Flashcards
The role of chromosomes and hormones
parts
The role of chromosomes
The role of hormones
Examples of hormones
└Testosterone , Oestrogen, Oxytocin
The role of chromosomes
└chromosomes: located in nucleus of cells, carry genetic information
└46 chromosomes in humans (23 pairs)
└23rd pair determines sex (XX= female XY= male)
└baby’s sex determines by the sperm that fertilises the egg
└if X= girl, if Y= boy
└Y chromosome carries gene called the ‘sex determining region Y’ aka SRY
└cases testes to develop in an XY embryo
└produces androgens (male sex hormones) → embryo becomes male
The role of hormones
└controls and regulates the activity of certain cells or organs
└controls most of gender development
└prenatally in womb
└act upon brain development, development of reproductive organs
└at puberty
└burst of hormones trigger secondary sexual characteristics e.g. pubic hair
└males and females produce the same hormones, but in different concentrations
└androgens (male sex hormones) important in male development
└e.g. testosterone
Hormone
definition
a chemical substance that is circulated in the blood
└controls and regulates the activity of certain cells or organs
Examples of hormones
list
Testosterone
Oestrogen
Oxytocin
Testosterone
└hormone from the androgen group (male sex hormones)
└produced mainly in male testes
└some in female ovaries
└associated with aggression
└Nanne Van de Poll et al (1988)
└female rats who had been injected with testosterone became more physically and sexually aggressive
Oestrogen
└primary female hormone
└important role in menstrual cycle and reproductive cycle
└pre-menstrual syndrome (PMS)
└some women have higher irritability in menstrual cycle
└has been used in defence of shoplifting and murder
Oxytocin
└woman typically produce larger amounts than men
└causes contraction of uterus in labour
└stimulates lactation
└reduces cortisol (stress hormone) and facilitates bonding
└=”love hormone”
└both sexes produce equal amounts in amorous activities such as kissing and sexual intercourse
The role of chromosomes and hormones
strengths
summary
Evidence supports the role of chromosomes - the case of David Reimer (1965)
Evidence supports the role of hormones - James Dabbs et al (1995), Stephanie Van Goozen et al (1995)
The role of chromosomes and hormones
strengths
Evidence supports the role of chromosomes
└influence of chromosomes on gender identity
└supported by the case of David Reimer (1965)
└Bruce and Brian Reimer were twins
└Bruce Reimer had botched circumcision operation at 6 months= no penis
└John Money believed in gender neutrality
└= raised Bruce as Brenda
└Money wrote of it as a success
└Brenda never adjusted
└severe emotional and psychological issues
└went back to David when told about situation
└committed suicide in 2004
└=chromosomes > environment
The role of chromosomes and hormones
strengths
Evidence supports the role of hormones
└influence of sex hormones on gender identity
└James Dabbs et al (1995)
└found that in a prison population, offenders with the highest testosterone levels were more likely to have committed violent or sexual crimes
└Stephanie Van Goozen et al (1995)
└studied transgender individuals who were undergoing hormone treatment (injected with hormones of opposite sex)
└transgender women: showed decreased aggression and visio-spatial skills
└transgender men showed the opposite
└=suggests sex hormones influence gender related behaviours
The role of chromosomes and hormones
limitations
summary
Contradictory evidence - Ray Tricker et al (1996), Ditte Slabbekoorn (1999)
Objections to pre-menstrual syndrome- Rodin (1992
Overemphasis on nature -Eleanor Maccoby and Carol Jacklin (1974)
Oversimplifies a complex concept
The role of chromosomes and hormones
limitations
Contradictory evidence
└Ray Tricker et al (1996)
└double-blind study
└43 males were given either a weekly injection of testosterone or a placebo
└no significant differences found after 10 week period between 2 groups
└Ditte Slabbekoorn (1999)
└demonstrated that sex hormones had no consistent effect on gender-related behaviour
└Many studies of biological factors on gender invol;ve small studies of unusual people, or animals
└=can’t generalise
The role of chromosomes and hormones
limitations
Objections to pre-menstrual syndrome
└Rodin (1992) + other feminist critiques
└claim PMS is a social construction
└way of privileging men over women > biological fact
The role of chromosomes and hormones
limitations
Overemphasis on nature
└if gender identity is purley down to biology
└would expect to find more differences in male and female behaviour
└Eleanor Maccoby and Carol Jacklin (1974)
└found significantly more differences within the sexes than between them
