start of aggression

Question 1

1. What is aggression?

Answer 1

Any act or behaviour that is aimed at harming a person or animal or damaging physical property.

Question 2

2. What are the types of aggression?

Answer 2

reactive-expressive (verbal and physical aggression), reactive-inexpressive (hostility), and proactive-relational (breaks human relationships.

Question 3

reactive-expressive

Answer 3

(verbal and physical aggression)

Question 4

reactive-inexpressive

Answer 4

(hostility)

Question 5

proactive-relational

Answer 5

(breaks human relationships.

Question 6

Neural and Hormonal Mechanism in Aggression

Answer 6

Biological explanations for aggression assume that aggression is located within the biological makeup of the individual rather than in the environment around them.

Question 7

The Limbic System (Hippo HAT)

Answer 7

• An area of the brain that helps to coordinate behaviours that satisfy motivation and emotional urges, such as aggression and fear.
• Two key structures associated with aggression are the amygdala and the hippocampus.

Question 8

Amygdala

Answer 8

• This is responsible for quickly evaluating the emotional importance of sensory information and prompting an appropriate response.
• If certain areas are stimulated electrically, an animal responds with aggression e.g., snarling.
• If the same areas are removed, the animal no longer response to that stimulus that previously led to rage.
• Gospic et al (2011): game under an FMRI scan, some participants were subjected to mild provocation. Aggressive reaction showed a fast and heightened response by the amygdala. Drug benzodiazepine was used to reduce arousal of the ANS, and it decreased the activity of the amygdala and halved the level of aggression.

Question 9

Gospic et al (2011

Answer 9

game under an FMRI scan, some participants were subjected to mild provocation. Aggressive reaction showed a fast and heightened response by the amygdala. Drug benzodiazepine was used to reduce arousal of the ANS, and it decreased the activity of the amygdala and halved the level of aggression.

Question 10

Orbitofrontal Cortex and Serotonin

Answer 10

• Serotonin is a neurotransmitter that has an inhibitory effect in the brain (slows it down).
• Normal levels of serotonin in the OFC is linked with reduced firing of neurons, which is associated with self-control.
• Low levels inhibits this mechanism, leading to increase in impulsive behaviour including aggression (Denson et al. 2012).

Question 11

Evaluation of Limbic System
Limited explanation

Answer 11

• Other structures (non-limbic) involved.
• OFC is not a part of the limbic system, involved in impulse regulation and inhibition of aggressive behaviour.
• Coccaro et al (2007), OFC activity is reduced in those psychiatric disorders that feature aggression. This reduced activity disrupts the OFC impulse-control function, which in turn causes aggressive behaviour.
• Neural regulation is more complex than theories that just focus on the amygdala.

Question 12

Supporting evidence

Answer 12

• Drugs like paroxetine that increase serotonin also found to reduce aggression.
• Berman et al. (2009) gave either a placebo or dose of paroxetine. Participants took part in lab-based game involving giving and receiving shocks when provoked.
• Paroxetine group consisted of much fewer and less intense shocks than placebo group.
• This shows a causal link between serotonin function and aggression.

Question 13

Hormonal Mechanisms testtornae

Answer 13

• The male sex hormone testosterone is an androgen responsible for the development of masculine features.
• Men tend to be more aggressive than women and become more aggressive than other men at a time in development (after age 20) when testosterone is the highest.
• Testosterone influences certain areas of the brain implicated in aggression.
• Castration studies of animals show that removing the testes reduces aggression in the males of many species. Giving injections to the same animals restores aggressive behaviour.
• Dolan et al. (2001) found highly positive correlation between testosterone levels and aggressive behaviours in a sample of 60 offenders (men) in maximum security hospitals. These men had mostly personality disorders and histories of impulsively violent behaviour.

Question 14

Progesterone

Answer 14

• Some evidence that progesterone levels play an important role in aggression in women.
• Levels vary during the ovulation cycle and are lowest during/just after menstruation. This is linked to reduced self-control and higher aggression.
• Ziomkiewicz et al. (2012) found negative correlation between progesterone levels and self-reported aggression.

Question 15

Evaluation
Animal research

Answer 15

• Testosterone and aggression higher in mating season.
• Giammanco et al’s (2005) review of studies confirms that in male rhesus monkeys there is an increase in both testosterone levels and aggressive behaviour during mating season.
• Rats that were castrated had less killing behaviour, female rats injected with testosterone had more.
• Shows testosterone effects in a range of species.

Question 16

Dual-hormone hypothesis

Answer 16

• Carre and Mehta says testosterone leads to aggression only when cortisol is low.
• When cortisol is high, testosterone’s influence on aggression is blocked.
• Cortisol plays a key role in the body’s response to chronic stress.
• Combined activity of hormones may be a better predictor of aggression than either hormone alone.