The role of chromosomes Flashcards
Hormones
Chemicals released from the endocrine glands. Travel in the bloodstream to target structures.
Androgens
Males hormones such as testosterone, which stimulate the development of the male reproductive system
AIS - Androgen insensitivity syndrome
Androgen receptors fail to recognize the circulating male hormones so the male reproductive system does not develop
Klinefelter’s syndrome
Condition in males that results from an XXY chromosome pattern.
- Normal male genitalia but smaller testes
- Don’t produce sperm and infertile
- Normal external genitalia - not detected until around 13 or 14 - puberty
Turner’s syndrome
Condition in females that results from a partially or fully missing X chromosome - random and linked to infertility.
- Normal external genitalia - not detected until around 13 or 14 - puberty
Testosterone
Male hormone or androgen that is released from the testes
Lutchmaya, Baron-Cohen and Raggatt - 2002
- Measured the amount of testosterone in the amniotic fluid of pregnant women.
- Observed the interaction between infants and mothers.
- Negative correlation = level of eye contact + testosterone
Higher testosterone = less eye contact - Infants’ interest in social relationships may be related to testosterone levels.
- Vocab size link in 18 + 24 months = boys slower.
Young - 1964
- Impact of prenatal sex hormones on behaviour
- Rats - reach sexual maturity quickly + male and female show different behaviours when mating.
- Male’s mount and females crouch
- Hormones given to pregnant rats = behaviour of offspring
- Male hormones = dominant and tried to mount females
- Female hormones = crouched
- Post mortem from 70s and 80s = brain difference in m + f in the area called the hypothalamus.
- Sexually dimorphic nucleus 2 times larger in males
- Hormones affected the size of this
- Rhesus monkeys - same results
Animals experiments
- High degree of control
Hypothalamus
Area of the forebrain involved in physiological functions such as regulating sexual behaviour
Case studies of CAH - Hines et al - 1994
- 1994 - examined amount of rough play shown by CAH girls and boys - 3 to 8 years
- Compared to control
= CAH girls preferred to play with boys + cars rather than dolls - Prenatal testosterone may lead to girls to develop more boyish behaviours
Case studies of CAH - Hines et al - 2004
- Compared group of 16 adult CAH women and 9 CAH men with unaffected relatives
- Asked to recall childhood behaviours
- CAH women recall more boy related behaviours
- Men with CAH didn’t differ with non-CAH men.
Case studies of CAH - Hines et al - 2014
- 43 CAH girls and 38 CAH boys
- Compared with a control group of 72 unaffected relatives.
- Interviews with their parents + used DSM diagnostic tool for gender dysphoria = cross-gender identification
- CAH girls = more likely to gives cross-gender responses
- 12% of female CAH = cross-gender behaviours consistently across both measurements.
Triangulation
- Approaching an issue from different angels to allows researchers to cross-check their findings
- Case studies = qualitative data that is rich in detail + large samples
- Hines used a variety of methods
Maguire et al - 2006
- Gray matter in the hypothalamus increased in volume as taxi drivers learned to navigate around London
- Experiences continue to affect brain structures
