aggression Flashcards
What is the difference between hot-blooded and cold- blooded aggression
- Proactive aggression (cold blooded) – A pre meditated way of getting what you want e.g. rape, murder.
- Reactive aggression (hot blooded) – Angry and impulsive behaviour coupled with physiological arousal.
What are the economic implications of aggressive behaviour
• Police costs
• Court costs
• NHS costs – ambulance service and therapeutic treatments • Lost worker productivity
• Property damage
What are the two neural explanations
These are explanations relating to a nerve or the nervous system including brain anatomy and neurotransmitters that allow communication between neurons. You need to know:
• The limbic system
• levels serotonin
What is the limbic system
- MacLean (1952) introduced the term the limbic system which is the centre of emotional regulation. It includes the hypothalamus, amygdala and regions of the hippocampus.
What is the relationship between the amygdala and aggression
- The reactivity of the amygdala in mammals is an important predictor of aggressive behaviour as it has a key role in responding to environmental threats.
- The more reactive a person’s amygdala the higher levels of aggression shown.
Gospic et al - the amygdala
- In this research ppts played ‘The Ultimatum Game’. Subject A (the Proposer) is given a sum of money but has to offer subject B (the Responder) some. If subject B accepts the offer, they both keep the money but if subject B rejects it, they both lose the money.
- The researchers used a fMRI to monitor brain activity while playing.
- They found that when subject B rejected the offer, there was a fast heightened response in the amygdala
- In conclusion it suggests an association between reactive aggression and the amygdala.
The role of serotonin in aggression
- Serotonin has widespread inhibitory effects on the brain, slowing down
neuronal activity. - Aggression in humans and animals is associated with low levels of
serotonin. - Normal levels in the OFC reduce the firing of neurons and allow for a greater degree of behavioural self-control. Decreased levels disturb this mechanism reducing self-control and increasing impulsive behaviour (including aggression).
Virkunnen et al - levels of serotonin
- Compared levels of a serotonin breakdown product (5-HiAA) in the cerebrospinal
fluid of violent impulsive and violent non-impulsive offenders. - Results: The levels were significantly lower in the impulsive offenders. This is because the reduction of the 5-H1AA means there is decreased serotonin activity in the brain which influences the ability to control impulsive (reactive) aggressive behaviour.
What are the two hormones related to aggression
- testosterone
- progesterone
Role of testosterone in aggression
- Testosterone is an androgen responsible for the development of masculine features and it is thought to be linked to aggressive behaviour.
- Males are generally more aggressive than females and have higher levels of testosterone. Aggression in males is highest around 20+ years old when testosterone peaks.
What have animal studies shown about this relationship
Giammanco et al (2005) have demonstrated experimental increases in testosterone are related to greater aggressive behaviour and the removal of the testes reduces aggression in many animal species.
What have prison studies shown about this relationship
Dolan et al (2001) found a positive correlation between testosterone levels and
aggression in a sample of 60 male offenders in UK maximum security hospitals.
The men mostly had personality disorders and history of impulsive (reactive) violent behaviour.
What is the relationship between progesterone and aggression
- There is some evidence that progesterone plays an important role in aggression in women.
- Levels of progesterone vary during the ovulation cycle are lowest after menstruation.
- Ziomkiewick (2012) found a negative correlation between progesterone levels and self-reported aggression. This suggesting low levels of progesterone are linked to increased aggression in women.
What types of studies are carried out to find out the genetic component of aggression
- To determine the genetic component of aggression (nature) vs the environmental component (nurture) each influence needs to be disentangled.
- This can be done by looking at twin, adoption and family studies.
Why are twin studies useful
Twin studies are useful for comparing the concordance rates for both monozygotic (MZ) and dizygotic (DZ) twins.
If MZ twins have a higher concordance rate it suggests there is a genetic component as they share 100% of the same DNA, rather than 50% like DZ twins.
What did coccaro et al find about genetics and aggression
Coccaro et al (1997) studied aggressive behaviour in adult twins. Researchers found that MZ twins had concordance rates of 50% and DZ twins 19% for physical assault and 28% and 7% respectively for verbal assault.
Limitation of twin studies
Twins are brought up in the same environment and therefore could be those factors having an impact
Why are adoption studies useful
In adoption studies if a positive correlation is found between aggressive behaviour in adopted children and aggressive behaviour in their adopted parents, then an environmental effect is implied.
If the correlation is between the adopted child and their biological parents, then a genetic effect is implied.
Rhee and Walman - genetics and aggression
- carried out a meta-analysis of adoption studies of direct aggression and anti-social behaviour (a prominent feature being aggression).
- They found they genetic influences accounted for 41% of the variance in aggression – in line with the same finding as twin studi