Testosterone Flashcards
Sex hormones are produced by the…
gonads (ovaries + testes) and adrenal gland
2 main types of sex hormones
androgens (including testosterone + anabolic steroids)
oestrogen (including estradiol)
Sex hormones are important in the…
development of sexually distinct traits in humans
Although both present in everyone, ________ are viewed as the ‘male’ hormone and _______ as the ‘female’ hormone.
male - androgens
female - oestrogen
Primary characteristics of testosterone
causes maturation of male genitalia and sperm production
Secondary characteristics of testosterone
facial + genital hair voice change shifts in hairline muscle development redistribution of body fat
In females, testosterone is produced in…
adrenal cortex and ovaries
There is _____ times more testosterone in males than in females.
seven
2 measures of testosterone
fluctuating levels
prenatal levels
Fluctuating levels of testosterone account for…
competition
aggression
dominance
Prenatal levels of testosterone account for…
physical features - e.g. facial structure, digit length, symmetry
Greatest difference in testosterone is between week __ and week __ of gestation
8 and 16
Foetal testosterone and brain lateralisation
Geschwind & Galaburda (1985):
Foetal testosterone facilitates growth in regions of the RIGHT hemisphere, and inhibits growth in the same regions of the LEFT hemisphere
Foetal testosterone and ‘male’ behaviour
Goy et al. (1988)
- Pregnant rhesus monkeys injected with testosterone
- Daughters born with external male genitalia and displayed more male behaviours in infancy e.g. rough play
- Mothers injected with T last in pregnancy had daughters with male behaviour but NOT genitalia
Foetal testosterone and spatial ability
Williams et al. (1990)
- Female rats injected after birth perform better than other females on maze learning and as well as male rats (exposed to fT throughout gestation)
- peri-natal as well as pre-natal effects of testosterone
Baron Cohen (2003) - E type brain
females are better at empathy; the drive to identify another’s emotions and to respond to them with the appropriate emotion
Baron Cohen (2003) - S type brain
males are better at systemising; the drive to analyse, explore and construct a system
Baron Cohen (2003) - characteristics of autism
high systemising
low empathy
Autism is ___ times more prevalent in males
4
Eye contact in 1 year olds
girls make significantly more eye contact than boys
demonstrates a link between prenatal hormone levels and social development
RESEARCH: In 4 year olds, foetal testosterone correlated negatively with… and positively with…
negatively with quality of social relationships
positively with restricted interests (boys)
RESEARCH: In 6-10 year olds, foetal testosterone correlates with…
score on the Childhood Autism Spectrum Test and the Child Autism Spectrum Quotient
What is amniocentesis and what is it used for?
Removal of small amount of amniotic fluid from amniotic sac around developing foetus - used to measure foetal testosterone levels
How do you measure the 2D:4D ratio?
Length of 2nd digit compared to 4th digit
2D:4D ratio negatively correlates with…
prenatal testosterone levels
Who has a higher 2D:4D ratio, males or females?
females
2D:4D ratio - why?
The formation of the testes and the digits are commonly influenced by Homeobox gene
Therefore genetic effects of testes production of testosterone also affects digit growth
2D:4D ratio is lower in…
professional footballers
players in 1st team squads
international players
2D:4D and sporting ability - suggests that…
foetal testosterone promotes development of traits important in male physical display and competition
2D:4D ratio also predicts:
financial trading spatial ability aggression personality musical ability sexuality skiing ability sperm production
RESEARCH: 2D:4D and autism
lower 2D:4D ratios in autistic children, as well as their immediate family members
Suggests we may be able to use 2D:4D ratio as an early indicator of likelihood of having offspring with autism
