aggression

Question 1

What is the difference between hot-blooded and cold- blooded aggression

Answer 1

• 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.

Question 2

What are the economic implications of aggressive behaviour

Answer 2

• Police costs
• Court costs
• NHS costs – ambulance service and therapeutic treatments • Lost worker productivity
• Property damage

Question 3

What are the two neural explanations

Answer 3

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

Question 4

What is the limbic system

Answer 4

• 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.

Question 5

What is the relationship between the amygdala and aggression

Answer 5

• 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.

Question 6

Gospic et al - the amygdala

Answer 6

• 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.

Question 7

The role of serotonin in aggression

Answer 7

• 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).

Question 8

Virkunnen et al - levels of serotonin

Answer 8

• 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.

Question 9

What are the two hormones related to aggression

Answer 9

• testosterone
• progesterone

Question 10

Role of testosterone in aggression

Answer 10

• 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.

Question 11

What have animal studies shown about this relationship

Answer 11

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.

Question 12

What have prison studies shown about this relationship

Answer 12

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.

Question 13

What is the relationship between progesterone and aggression

Answer 13

• 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.

Question 14

What types of studies are carried out to find out the genetic component of aggression

Answer 14

• 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.

Question 15

Why are twin studies useful

Answer 15

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.

Question 16

What did coccaro et al find about genetics and aggression

Answer 16

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.

Question 17

Limitation of twin studies

Answer 17

Twins are brought up in the same environment and therefore could be those factors having an impact

Question 18

Why are adoption studies useful

Answer 18

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.

Question 19

Rhee and Walman - genetics and aggression

Answer 19

• 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

Question 20

Hutching and mednick - genetics and aggression

Answer 20

carried out a study on 14,000 adoptions in Denmark found that a significant number of adopted boys with criminal convictions had biological parents, especially fathers, with criminal convictions.

Question 21

What gene has been linked to aggression

Answer 21

• The MAOA gene controls the production of the MAO-A enzyme which regulates the metabolism (breakdown) of serotonin. As learnt in the previous topic low levels of serotonin are associated with high levels of aggression.
• Genes can come in high or low variants. The MAOA-L results in low activity of the MAO-A enzyme. This gene has been linked to high levels of aggression.

Question 22

Why is the MAOA dubbed the warrior gene

Answer 22

MAOA-L has also been dubbed the warrior gene because it is seen much more frequently in populations with a history of warfare – with 2/3rds of these populations having low activity versions.

Question 23

Brunner et al - genetics and aggression

Answer 23

• studied a Dutch family in which 28 of the males behaved very aggressively and violently e.g. rape, attempted murder and assault.
• These men were found to have abnormally low levels of MAO-A enzyme and the MAOA-L gene variant and as a result is now referred to as Brunner Syndrome.

Question 24

Why might it not be genes alone that cause aggression

Answer 24

• Genes do appear to have a crucial role in aggression, but they do not function in isolation. It appears that MAOA-L gene activity is only correlated with adult aggression when combined with traumatic life experiences.
• This can be explained using the diathesis-stress model.

Question 25

What did Frazzetto et al find

Answer 25

found an association between higher levels of the MAOA-L gene in men but only if they had also experienced significant trauma, such as sexual or physical abuse, during the first 15 years of life. Those who had not experienced childhood trauma did not have particularly high levels of aggression as adults, even if they possessed the MAOA-L gene.

Question 26

What is ethology

Answer 26

Ethology is the study of animal behaviour in a natural setting.

Question 27

Key terms for ethological explanation

Answer 27

• Adaptive functions • Ritualistic aggression • Innate releasing mechanisms (IRMs) and fixed action patterns (FAPs)

Question 28

Founder of ethology and how he defines aggression

Answer 28

Konrad Lorenz - He defined aggression as “the fighting instinct in beasts and man that is directed against members of the same species”.

Question 29

Assumptions of ethology

Answer 29

• Aggression is an instinct. It occurs in all members of a species without the need for learning. It is innate and mostly genetically determined (link with previous section). • We can study non-human animals and extrapolate to humans because we are all subject to the same laws of natural selection.

Question 30

Adaptive meaning

Answer 30

Ethological explanations suggest that the main function of aggression is adaptive. This means it is beneficial for the species.

Question 31

One adaptive function of aggression

Answer 31

- After an aggressive encounter the ‘losing’ animal is rarely killed (see next slide on ritualistic aggression). Instead, the loser is forced to move into another area. - This is adaptive because it spreads individuals out over an area which reduces competition for resources.

Question 32

Second adaptive function of aggression

Answer 32

- It allows for the formation of a dominance hierarchy. This is adaptive because dominance brings benefits such as mating rights. - Also, once the dominance hierarchy is established it reduces the incidences of aggression between individuals.

Question 33

Pettit et al - dominance hierarchies in humans

Answer 33

Studied play groups of young children and observed that aggressive interactions were an important aspect of how some children gain dominance over others.

Question 34

What is a ritual

Answer 34

A ritual is a series of behaviours carried out in a set order.

Question 35

What is ritualistic aggression

Answer 35

Lorenz observed that in fights between animals, actual injury is rare. Most aggressive interactions consist of ritualistic signalling (snarling, displaying claws, pushing contests) and rarely becomes physical.

Question 36

What is an appeasement display

Answer 36

- Lorenz suggested that intra-species (within-species) aggressive confrontations end with a ritual appeasement display. - These are thought to indicate acceptance of defeat and thus inhibit any further aggression from the victor and thus preventing actual injury). - This is adaptive because if aggressive encounters ended with injury or death it could threaten the existence of the species.

Question 37

What did Lorenz argue about appeasement in wolves

Answer 37

Lorenz suggested that the wolf showing its jugular vein is an appeasement signal. However, Schenkel (1967) argues against this view and suggests that this ‘submissive’ pose is actually a challenge that leads to further fighting.

Question 38

What is an innate releasing mechanism

Answer 38

An IRM is a biological structure or process triggered in the brain, which is activated by an external stimulus that in turn triggers a fixed action pattern.

Question 39

What is a fixed action pattern

Answer 39

A fixed action pattern (FAP) is a sequence of stereotyped pre-programmed behaviours triggered by an innate releasing mechanism.

Question 40

What are features of FAPs

Answer 40

Lea (1984) argues FAPs have six main features: • Stereotyped, unchanging sequence • Universal within the species • Unaffected by learning • Ballistic, once started they must continue • Single purpose, only occurring in one type of situation • A response to an identifiable and specific stimulus, called a releaser if intra- specific

Question 41

Outline Tinbergens study on sticklebacks

Answer 41

- Male stickleback fish are very territorial in the mating season. During this season, males develop a red underbelly. - If another male enters their territory a FAP is released in response to the releaser/sign stimulus of the colour red. - Tinbergen presented sticklebacks with a series of wooden models of different shapes. He found regardless of the shape (even if the shape was not realistic of a fish) if there was a red spot the stickleback would attack it. No red spot – no attack. - The FAP always ran its course to completion without any other stimulus.

Question 42

What is a cuckold

Answer 42

- A cuckold is the a husband of a cheating wife and cuckoldry creates a threat of paternity uncertainty - It is an evolutionary waste of resources to raise children who are not a male’s own as it is contributing to the survival of a competitor's genes

Question 43

How can cuckoldry explain aggressive behaviour

Answer 43

- Men in the evolutionary past who avoided cuckoldry were more reproductively successful and therefore adaptive psychological mechanisms have evolved to increase anti-cuckoldry behaviours in males - This can drive aggressive strategies by men to retain their partners and prevent them from straying

Question 44

The two male retention strategies (Wilson and Daly)

Answer 44

Direct guarding - Male vigilance over a partner’s behaviour e.g. checking who they’ve been seeing, coming home early, keeping tabs on their whereabouts, tracking them Negative inducements - Issuing threats of dire consequences e.g. threatening to kill themselves if a partner leaves

Question 45

What did Wilson find out about mate retention strategies

Answer 45

- found that women who reported mate retention strategies in their partners were twice as likely to have suffered physical violence at the hands of their partners - Of these women, 73% required medical attention and 53% said they feared for their lives.

Question 46

What is bullying

Answer 46

- A power imbalance where a more powerful individual uses aggression against a weaker e person - evolutionary explanation suggests it is an adaptive strategy to increase chances of survival by creating reproduction opportunities

Question 47

Why might bully - associated characteristics be classed as adaptive

Answer 47

- Characteristics associated with bullying behaviour are attractive to females as it suggest dominance, acquisition of resources and strength and can ward off potential rivals - Bullying-associated characteristics therefore deliver access to more females and minimal threat from competing males which would be natural selected because males can reproduce more.

Question 48

Female bullying

Answer 48

- Female bullying more often takes place within a relationship and is a method of control to help secure the males fidelity. - The partner continues to provide resources for future offspring and the behaviour is naturally selected because it enhances the women’s reproductive success.