AGGRESSION Flashcards
outline Ritualistic aggression (A01)
One aspect of the ethological explanation of ritualistic aggression. A ritual is a series of behaviours carried out in a set order. In some of Konrad Lorenz’s early observations of fights between animals of the same species he noted how little actual physical damage was done. Most aggressive encounters consisted mainly of a period of ritualistic signalling (e.g. displaying claws and teeth, facial expressions of threat) and rarely reached the point of becoming physical. Furthermore, Lorenz recognised that intra-species (within species) conflicts end with ritual appeasement displays (showing you are no longer a threat). These indicate acceptance of defeat and inhibit aggressive behaviour in the victor. For example, a wolf will expose its neck to the victor, deliberately making itself vulnerable to reduce further aggression. This is adaptive because if every aggressive encounter ended in death, this could threaten the existence of the species.
what is the IRM
An innate releasing mechanism (IRM) is a built-in physiological process or structure, for instance a network of neurons (a circuit) in the brain. An environmental stimulus (such as a certain facial expression for a rival) triggers the IRM which then communicates with the motor control circuits to ‘release’ a specific sequence of aggressive behaviours – the fixed action patterns.
actions leading to a aggressive behaviour
Stimulus (showing teeth)
IRM (brain networks)
FAP (aggressive behaviour)
Fixed action patterns (FAPS) can be characterised by five main features:
what are they?
B
U
U
S
S
Ballistic – once the behaviour is triggered, it cannot be changed or stopped
Universal – the same behaviour is shown in all members of the species
Unaffected by learning – the same for everyone regardless of experience
Single purpose – the behaviour only occurs in a specific situation and not in any other
Stereotyped – the behaviour always occurs in the same way
Ethological aggression (A03)
Criticism of fixed action patterns for aggression.
Lehrman (1953)
Lehrman (1953) criticised Lorenz’s instinctual explanation of aggressive behaviour. Lehrman believed that Lorenz had underestimated the role of environmental factors in the development of species-typical aggressive behaviour patterns. These environmental factors (for example, aggressive peers or parents), interact with innate factors in complex ways. There are subtle variations between members of the same species in the production of aggressive behaviours, showing that patterns of aggressive behaviour are not as fixed as Lorenz claimed.
Ethological aggression (A03)
Nisbett (1993)
Cultural differences in aggression.
Cultural differences in aggression. There is evidence that aggressive behaviour is more common in some human cultures than ¡n others. For example. Nisbett (1993) found there was a north-south divide in the United States for homicide rates. Killings are much more common amongst white males in the southern states than in the northern states. Because this was only true for reactive aggression (aggression triggered by arguments), Nisbett concluded that the difference in homicide rates was caused by a ‘culture of honour’, in other words the response to impulsive aggression was a learned social norm. This shows how culture/learning may play a role in aggression and therefore not be innate.
The benefits of ritualised aggression.
The benefits of ritualised aggression. In non-human species, the main advantage of ritualised aggression is that it prevents conflicts escalating into potentially dangerous physical aggression. Anthropological evidence suggests that this advantage is also evident in human cultures.
For example, Chagnon (1992) describes how, among the Yanomamö people of South America, chest pounding and club fighting contests can settle a conflict before more extreme violence.
Similarly, Floebel (1967) found that, among Inuit Eskimos, ‘song duels’ are used to settle grudges and disputes. This shows that, violent cultures such as the Yanomamo, rituals have the effect of reducing actual aggression and preventing injury or death of the combatants.
Evidence against ritualistic aggression.
Jane Goodall (2010)
The view that aggression has evolved into relatively physically harmless ritual has been challenged by observations made by Jane Goodall (2010) of chimpanzees at the Gombe Stream National Park ¡n Tanzania. During what she called the ‘four-year war’, male chimps from one community set about systematically killing all the members of another group. They did this in a coordinated way. On some occasions, a victim was held down by some rival chimpanzees while others hit and bit it in an attack lasting up to 20 minutes. The violence continued like this despite the fact that the victims were offering signals of appeasement and defencelessness. These signals did not inhibit the aggressive behaviour of the attacking chimps as predicted by the ethological explanation.
Evolutionary reason for aggression (A01)
Sexual Jealousy
Sexual jealousy is a major motivator of aggressive behaviour in males which can be given an evolutionary explanation. This is because, unlike women, men can never be totally sure about whether or not they have truly fathered a child. This paternity uncertainty is a result of the very real threat for the male of cuckoldry (having to raise offspring that are not his own).
Any investment in offspring that do not share the male’s genes is a waste of his resources e.g. his time, effort, food etc. It contributes to survival of a rival’s genes and leaves the ‘father’ with fewer resources to invest in his own future offspring.
Men in our evolutionary past who could avoid cuckoldry were more reproductively successful. So psychological mechanisms have evolved to increase anti-cuckoldry behaviours in males such as sexual jealousy and possessive behaviours. This drives the often aggressive strategies men employ to retain their partners and prevent them from ‘straying’, strategies that were adaptive in our evolutionary history.
Evolutionary explanations for aggression (A01)
Mate retention strategies
Wilson and Daly (1996)
Wilson and Daly (1996) identified strategies a male may prevent a female from ‘straying’ which involve aggression and even physical violence, including:
Direct guarding - involves male vigilance over a partner’s behaviour, for example checking who they’ve been seeing, coming home early, keeping tabs on their whereabouts, installing tracking apps on their mobiles, etc.
Negative inducements - such as issuing threats of dire consequences for infidelity e.g. ‘I’ll kill you if you cheat on me’. This can include verbal or physical abuse.
Gaslighting - This is a form of psychological abuse where someone is made to question their sanity, perception of reality, or memories. People experiencing gaslighting often feel confused, anxious, and unable to trust themselves, resulting in them becoming overly dependent on their partner (the ‘gaslighter’).
Evolutionary explanations for aggression (A01
Bullying
Bullying
Bullying occurs because of a power imbalance: a more powerful individual uses aggression deliberately and repeatedly against a weaker person. Researchers have traditionally viewed bullying as a maladaptive behaviour, for example the result of poor social skills or childhood abuse.
However, our evolutionary ancestors may have used bullying as an adaptive strategy to increase their chances of survival by promoting their own health and creating opportunities for reproduction. Yolk et aI. (2012) argue that the characteristics associated with bullying behaviour are attractive to the opposite sex.
In males, it suggests dominance, acquisition of resources, and strength. It also has the benefit of warding off potential rivals. Therefore such behaviour would be naturally selected because these males would have greater reproductive success.
Evolutionary explanations of human aggression (sexual jealousy and bullying) – AO3
research support Wilson et aI.link (1995)
Wilson et aI. (1995)
found that women who reported mate retention strategies in their partners (they agreed with statements like ‘He insists on knowing who you are with and where you are at all times’), 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. This suggests that mate retention strategies and strongly linked to human aggression.
Evolutionary explanations of human aggression (sexual jealousy and bullying) – AO3
gender differences
Evolutionary explanations account for gender differences. It is a common observation that males engage more often than females in most aggressive acts, especially physical aggression, i.e. there are gender differences. Evolutionary theory can explain this.
F Anne Campbell (1999) argues that a female with offspring is motivated to be less aggressive because such behaviour would put not only her own survival at risk but also that of her child.
So a more adaptive strategy for females is to use verbal aggression as a means of retaining a partner who provides resources, and to avoid becoming involved in life-threatening situations involving physical aggression (Buss and Shackelford 1997). This would also explain why women are more likely than men to use non-aggressive methods of resolving disputes. This ability to explain gender differences is a strength of evolutionary theory.
Evolutionary explanations of human aggression (sexual jealousy and bullying) – AO3
Practical applications.
Bullying: An evolutionary understanding of bullying as an adaptive behaviour can help us to devise more effective anti-bullying interventions. Since bullying may not be a learnt behaviour, but rather innate, Volk et al. argued that anti bullying interventions need to increase the costs of bullying and the rewards of pro-social alternatives.
One method could be to encourage bullies to compete aggressively but fairly in sporting activities. This would give them the opportunity to display prowess, strength and other attractive qualities, including some not available to them through bullying.
Mate retention strategies: many organisations use knowledge of mate retention strategies to provide guidance and support to those who may be at risk of experiencing physical harm if these strategies escalate. This includes workshops in schools, as well as adverts highlighting mate retention strategies in action, and information as to where to find support.
Evolutionary explanations of human aggression (sexual jealousy and bullying) – AO3
Alternative approach - SLT.
Kun San people
The SLT of aggression can explain differences in levels of aggression in different cultures. The ‘culture of violence’ theory proposes that some cultures emphasise and model aggressive behaviour whereas other cultures emphasise and model non-aggressive behaviour, and so are more likely to produce individuals with low levels of aggression.
For example, among the Kung San people of the Kalahari Desert, aggression is comparatively rare as Kung San parents do not use physical punishment and aggression is devalued by the society as a whole. The absence of aggressive models means there is little opportunity for the children to learn aggressive behaviour. This therefore suggests that perhaps an evolutionary explanation may not provide the best explanation but rather individuals modelling behaviour (either aggressive or non-aggressive) in the culture in which they live.
Neural mechanisms in aggression (A01)
The limbic system and the prefrontal cortex.
The limbic system and prefrontal cortex
Aggression is the result of an interaction between a system of brain structures. It appears aggressive impulses are created in the limbic system (comprising of, amongst others, the hypothalamus and amygdala). The most important structure by far appears to be the amygdala (a-mig-dala). This has a key role in humans and nonhuman animals in how they respond to perceived environmental ‘threats’ and challenges. The activity of the amygdala in humans has proven to be an important predictor of aggressive behaviour. Aggression therefore seems to be linked to an underdeveloped (smaller than average) amygdala.
apart from the amygdala, what else is linked to aggression neurologically.
In addition, another part of the circuit; the prefrontal cortex, is also stimulated by a threatening situation. In contrast to the primitive emotional amygdala, the prefrontal cortex is the rational part of the brain which is involved in impulse control and reasoning. Therefore, the prefrontal cortex usually exerts control over the aggressive urges created in the amygdala. Aggression may occur because of an underdeveloped prefrontal cortex.
Neural mechanisms in aggression.
seratonin hypothesis (A01)
Serotonin is typically considered an inhibitory neurotransmitter – it slows down and dampens neuronal activity (from other neurotransmitters). Normal levels of serotonin in the orbitofrontal cortex is linked with reduced firing of neurons, and this is associated with a greater degree of behavioural self-control. Serotonin appears to allow effective communication between the prefrontal cortex and the amygdala. Therefore, if serotonin levels are lower, the prefrontal cortex is unable to effectively regulate the activity of the amygdala.
Hormonal mechanisms in aggression (A01)
Testosterone
Research suggests that testosterone tends to be linked to higher levels of aggression at the points in life when the hormone is plentiful, for example, during puberty. This is a time when testosterone levels significantly increase, with adult males aged 15-25 having the highest levels.
It is believed that testosterone doesn’t necessarily cause someone to become aggressive, but rather amplifies pre-existing aggression. Testosterone lowers the threshold to which the amygdala judges threatening situations (e.g. a threatening face).
Mazur & Booth (1998) suggest testosterone plays a significant role in dominance, competition and anti-social behaviour, however the nature of the link between testosterone and aggressive behaviour is not a simple ‘cause and effect’ mechanism. It is suggested that higher levels of testosterone rather than causing aggression, make it more likely that a particular behaviour, such as aggression, will be expressed. Possibly due to impaired control.
AO3 – Neural and hormonal mechanisms in aggression.
Pardini (2014)
Evidence for the role of the amygdala in aggression. Pardini (2014) found that reduced amygdala volume can predict the development of severe and persistent aggression. They carried out a longitudinal study of male participants from childhood to adulthood. At age 26, those with lower amygdala volume showed higher levels of aggressive behaviour (the amygdala is not able to accurately judge environmental threats, and the individual becomes less ‘fearful’). The relationship remained even after other confounding variables were controlled. This suggests that the amygdala plays an important role in evaluating the emotional importance of sensory information.
AO3 – Neural mechanisms in aggression.
Practical Application.
Badaway (2006)
Practical Application. The influence of neural mechanisms may have practical application in dealing with the well-established relationship between alcohol and aggressive behaviour. Badaway (2006) found that alcohol consumption caused major disturbances in levels of serotonin. In particular, acute (short term) alcohol intake depleted serotonin levels in normal individuals. In susceptible individuals, this depletion may result in aggressive behaviour as serotonin is essential in dampening down aggressive impulses.
This has practical application as it suggests that we should educate people with aggressive tendencies to reduce the amount of alcohol they consume, in order to avoid aggressive behaviour.
AO3 – hormonal mechanisms in aggression.
Research support
Dabbs et al (1995)
Research support. Strong research comes from Dabbs et al (1995) who found a significant correlation to suggest there is a link between testosterone and aggression in offenders. Salivary testosterone was measured in a sample of 692 criminals.
It was found that those with the highest levels of testosterone had a history of violent crimes whereas those with the lowest levels were more likely to have committed non-violent crimes.
However, as the research is correlational, cause and effect cannot be established. For instance it cannot be stated that the increase of testosterone directly causes aggressive behaviour as other factors both biological and social (e.g. trauma) may have an influence too.
AO3 – hormonal mechanisms in aggression.
Carre and Mehta’s (2011) cortisol mixed
The role of cortisol.
Evidence of the link between testosterone and aggression in humans is mixed. AO3 – hormonal mechanisms in aggression.
Carre and Mehta’s (2011) dual-hormone hypothesis attempts to explain why. They claim that high levels of testosterone lead to aggressive behaviour only when levels of cortisol are low. When cortisol is high, testosterone’s influence on aggression is blocked. This suggests that the combined activity of testosterone and cortisol may be a better predictor of human aggression than either hormone alone.
genetic factors in aggression (A01)
MAO‘A’ gene
Psychologists have identified a ‘Candidate’ gene, located on the X chromosome that encodes the enzyme Monoamine Oxidase A (MAOA). The enzyme produced breaks down important neurotransmitters such as serotonin, noradrenaline and dopamine (monoamines). These neurotransmitters stabilise mood, aggression, and pleasure and imbalances are thought to increase the risk of engaging in aggressive anti-social behaviour. For example, noradrenaline is a neurotransmitter that raises blood pressure and increases alertness in the fight or flight response (leading to feelings of being on edge).
A normal level of MAOA makes these neurotransmitters inactive after they have carried the nerve impulses across the synapse. The production of this enzyme is determined by the MAOA gene. A dysfunction in the operation of this gene may lead to abnormal activity of the MAOA enzyme, which in turn affects levels of the neurotransmitters in the brain. One variant of the MAOA gene (nicknamed ‘the warrior gene’) leads to low MAOA activity in areas of the brain, and has been associated with various forms of aggressive behaviour.
genetic factors in aggression (A01)
Coccaro et al. Twin studies
Twin studies
It is suggested that some people may be aggressive due to genetic inheritance; therefore researchers compare concordance rates (degree of similarity) for traits such as aggression between MZ & DZ twins. In one of the few studies that specifically studied the genetic transmission of aggression (rather than general anti-social behaviour) Coccaro et al concluded genes accounted for more than 50% of variance in general aggression. This means in any one individual, 50% of their aggression is a result of genes, suggesting that genes play an important part in aggressive behaviour.