neural + hormonal mechanisms

Question 1

serotonin AO1

Answer 1

Lots of Serotonin receptors in the prefrontal cortex which are responsible for executive functioning.
∴ thought low levels of Serotonin may incr. aggression bc they reduce activity in the part of the brain responsible for inhibition + decision making

Question 2

research related to serotonin

Answer 2

ERP
rats who were rewarded for aggressive behavior showed reduced levels of serotonin in the prefrontal cortex over time and became more generally aggressive.
TS the model as it supports the link between low serotonin, to low pre frontal cortex activity and so incr. levels of aggression
NATURE vs NURTURE
o Neuroplasticity → rats where rewarded for aggression + as they where raised aggressive environment this caused a change in their biology + levels of serotonin activity
ISSUE → animal study BUT the link between serotonin + aggression have been found in humans

Question 3

LIMBIC SYSTEM AO1

Answer 3

Certain structures of the brain are related to aggression e.g limbic system
→ responsible for basic drives such as food + sex + core emotions of fear + aggression → AMYGDALA
o Responsible for regulating emotions + determining the level of aggressive response.
o Helps process fear + aggression as well as learning and sexual behaviour.
o Animals or humans with the amygdale damaged // removed have lowered aggression levels, whereas those in which the amygdale have been stimulated have incr. aggression.

Question 4

BASAL MODEL OF TESTOSTERONE AO1

Answer 4

Testosterone reaches a peak in young adult men + then decr w/ age.
The link between testosterone and aggression is not simple cause and effect but rather it makes it more likely that someone will be aggressive. This is because testosterone causes a change in a person’s dominance.
The more testosterone a person has the most competitive and dominant they become.

Question 5

CHALLENGE HYPOTHESIS AO1

Answer 5

In monogamous species, testosterone levels rise above the base line in response to social challenges (Wingfield).
The challenges in humans might be direct (e.g. dispute over a woman) or indirect (e.g. dispute over resources and status, both of which lead to reproductive success).

Question 6

HORMONES LACK OF CAUSE + EFFECT

Answer 6

CAUSE + EFFECT
We don’t know whether being aggressive is because you have high levels of testosterone
OR
if u have high levels of testosterone when you’re aggressive

Question 7

TESTOSTERONE RELATED RESEARCH

Answer 7

BEEMAN
Found that if he castrated mice they became less aggressive. When he then later injected them with testosterone they became aggressive again.
TS the basal model of testosterone as its shows altering testosterone levels changes the level aggression, establishing a causal relationship that testosterone is the cause of aggression.

BUT rats, lacks population validity as findings cannot be generalized to humans as we have different neurological structures (esp left cortext) → HOWEVER, there is evidence for this in humans from KOURI…

KOURI
Used a betting game with male pts where they could cooperate // punish someone. Those injected w/ more testosterone were significantly more likely to act aggressively.
TS a causal relationship where an incr in testosterone, causes an incr in aggression supporting the idea that aggression is caused by testosterone.

BUT

BOOK (meta-analysis)
45 studies found a mean correlation of 0.14 between testosterone and aggression.
TS low correlation between testosterone and aggression, showing that although it is a factor in increasing aggression it is not the main factor.
Too simplistic to say just testosterone, massive overstatement in the significance of hormones in aggression