Psychology-Aggression Flashcards
What are the neural influences of aggression?
The limbic system and serotonin
What is the limbic system?
An area of the brain that helps coordinate behaviours that satisfy motivational and emotional urges, such as aggression and fear. Two key structures in the limbic system that are associated with aggression are the amygdala and the hippocampus
How is the amygdala associated with aggression?
Responsible for quickly evaluating emotional importance of sensory information and prompting appropriate response. If certain areas of the amygdala are stimulated electrically, an animal responds with aggression, eg snarling/aggressive posture. If same areas are surgically removed, animal no longer responds to stimuli that would have previously led to rage. Eg Kluver and Bucy discovered destruction of amygdala in a monkey who was dominant in a social group caused it to lose its dominant place in the group
How is the hippocampus associated with aggression?
Involved in formation of long-term memories, so allows animal to compare conditions of current threat with similar past experiences. Eg if animal previously been attacked by another animal, they are likely to respond with aggression or fear if they encounter it again, whichever is more appropriate. Impaired hippocampal function prevents nervous system putting things in relevant/meaningful context, so may cause amygdala to respond inappropriately to sensory stimuli, resulting in aggressive behaviour. Eg Boccardi et al found habitually violent offenders either exhibited abnormalities of hippocampal functioning
What is serotonin?
In normal levels it exerts a calming, inhibitory effect on neural firing in the brain. It typically inhibits the firing of the amygdala, the part of the brain that controls fear, anger and other emotional responses. Low levels of serotonin remove this inhibitory effect with the consequence that individuals are less able to control impulsive/aggressive behaviour. As a result, when the amygdala is stimulated by external events, it becomes more active, causing the person to act on their impulses, making aggression more likely
How can serotonin reduce aggression but also increase it?
It can reduce aggression by inhibiting responses to emotional stimuli that might otherwise lead to an aggressive response. However low levels of Serotonin removes the inhibitory effect of serotonin on impulsive behaviour. Mann et al found that when serotonin levels were depleted in 35 healthy levels, hostility and aggression in males
What is the hormonal influence of aggression?
Testosterone influences aggression. Dabbs-salivary testosterone measured in violent criminals, high levels found in violent crimes and low levels in non-violent crimes. Challenge hypothesis - Humans are monogamous and their testosterone levels rise when it comes to social challenges/ reproductive competition. Testosterone is the primary biochemical influence on aggression and low cortisol levels play an important role in the likelihood of aggressive behaviour as cortisol has a mediating effect on other aggression-related hormones.
What are the evaluation points for neural influences of aggression?
Evidence for the role of the amygdala in aggression, evidence for the role of the hippocampus in aggression, research support for serotonin deficiency hypothesis, and evidence from studies of non human-species
How is ‘Evidence for the role of the amygdala in aggression’ an evaluation point for neural influences of aggression?
Pardini et al-reduced amygdala volume can predict development of severe/persistent aggression. Carried out longitudinal study of male participants from childhood to adulthood. 56 had varying histories of violence and were subjected to a brain MRI at age 26. Results showed lower amygdala volumes exhibited higher levels of aggression/violence. Relationship between amygdala volume and aggressive behaviour remained even after other confounding variables were controlled, suggesting amygdala plays important role in evaluating emotional importance of sensory information and lower volume of it compromises this ability making violence more likely
How is ‘evidence for the role of the hippocampus in aggression’ an evaluation point for neural influences of aggression?
Raine et al-support for role of hippocampus in aggressive behaviour in study of violent offenders. Studied two groups of violent criminals: some faced conviction and some had evaded the law. The ones who had evaded law were considered ‘cold, calculating criminals’ whereas the others had acted more impulsively, which is why they were caught. MRI scans revealed asymmetries in hippocampus in ‘unsuccessful’ group. This may impair ability of hippocampus and amygdala to work together leading to inappropriately verbal and physical responses
How is ‘research support for serotonin deficiency hypothesis’ an evaluation point for neural influences of aggression?
Duke et al. Meta analysis of 175 studies involving 6500 participants. Found small inverse relationship between serotonin levels and aggression, anger and hostility. Also found magnitude of the relationship varied with methods used to assess serotonin functioning, with year of publication and with self reported versus other reported aggression. Only other reported aggression was positively correlated to serotonin functioning suggesting the relationship is more complex than originally thought
How is ‘evidence from studies of non human-species’ an evaluation point for neural influences of aggression?
Raleigh et al-vervet monkeys fed on experimental diets of tryptophan (increases serotonin) exhibited decreased levels of aggression. Individuals on diets low in tryptophan exhibited increased aggressive behaviour, suggesting difference in aggression could be attributed to their serotonin levels. Similar evidence comes from studies of aggressive dogs
How is ‘Inconsistent evidence’ an evaluation point for hormonal influences of aggression?
Many studies show positive relationship between testosterone and aggression but others show no such relationship, particularly those that have compared testosterone levels of aggressive and less aggressive individuals. Eg positive correlations reported between levels of testosterone and self reported levels of aggression among prison inmates but no correlation between testosterone levels and actual violent behaviour among male inmates in prison, suggesting relationship between testosterone and human aggression remains unclear
How is ‘aggression or dominance?’ an evaluation point for hormonal influences of aggression?
Mazur suggests we should distinguish aggression from dominance. Individuals act aggressively when their intent is to inflict injury, whereas they act dominantly if their wish is to achieve/maintain status over another individual. Claims aggression is one form of dominance behaviour. In non-human animals the influence of testosterone on dominance behaviour may be shown through aggressive behaviour. In humans however the influence of serotonin on dominance is likely to be expressed in more varied/subtle ways eg status-striving behaviour, eg Eisenegger et al found testosterone could make women act ‘nicer’ rather than aggressively depending on situation. Supports idea testosterone promotes status-seeking behaviour, of which aggression is one type, rather than directly increasing aggression
What are genetic factors?
The likelihood of behaving in a particular way is determined by a person’s genetic makeup, i.e. it is inherited from parents
What ways can genetic factors in aggression be studied?
Twin studies, adoption studies, and other research on genetic factors in aggression
What are twin studies into aggression?
Monozygotic twins share all genes, dizygotic share 50% of genes. Twin studies are used to compare degree of similarity for particular trait (eg aggression) between MZ twins and compare to similarity between DZ twins. If MZ are more alike then it suggests genes rather than environment explain the trait
What is an example of a twin study into aggression?
Coccaro et al. Used adult twin pairs and found that nearly 50% of the variance in direct aggressive behaviour (i.e. aggression toward others) could be attributed to genetic factors
What are adoption studies into aggression?
Can help untangle relative contributions of environment/heredity in aggression. If a positive correlation is found between aggressive behaviour in adopted children and aggressive behaviour in biological parents, a genetic effect is implied. If positive correlation found between adoptee’s aggressive behaviour and the rearing family, then an environmental effect is implied
What is an example of an adoption study into aggression?
Hitchings and Mednick. A study of over 14000 adoptions in Denmark found that a significant number of adopted boys with criminal convictions had biological parents (particularly fathers) with convictions for criminal violence, providing evidence for a genetic effect
What are examples of research into genetic factors in aggression?
Miles and Carey, and Rhee and Waldman
What was Miles and Carey’s study?
Carried out a meta analysis of 24 twin and adoption studies that demonstrated the genetic basis of aggression. The results suggested a strong genetic influence that could account for as much as 50% pf the variance in aggression. Age differences were notably important, with both genes and family environment being influential in determining aggression in youth, but at later ages the influence of rearing environment decreased and the influence of genes increased
What was Rhee and Waldman’s study?
A later meta analysis combined the results of 51 twin and adoption studies and also concluded that aggressive anti social behaviour was largely a product of genetic contributions. However, in this study, as with Miles and Carey’s study, several variables, including age of participant and assessment method for aggression, moderated the genetic influence on aggression, suggesting that, although genetic factors play a significant part in the development of aggressive behaviours, the influence of other factors affects their expression
What is MAOA?
Monoamine Oxidase A (MAOA) is an enzyme that, among other things, regulates the metabolism of serotonin in the brain
What is the role of MAOA?
Although no individual gene for aggression has been identified in humans, a gene responsible for producing an enzyme (MAOA) has been associated with aggressive behaviour. MAOA regulates metabolism of serotonin in brain and low levels of serotonin are associated with impulsive and aggressive behaviour
What research supports MAOA’s role in aggression?
Brunner et al. In the 1980s a study of a Dutch family found that many of its male members behaved in a particularly violent and aggressive manner, and a large proportion had been involved in serious crimes of violence, including rape and arson. These men were found to have abnormally low levels of MAOA in their bodies, and a defect in this gene was later identified
What did a second study into MAOA by Caspi et al find?
Their study involving 500 male children linked MAOA to aggressive behaviour as well. Researchers discovered a variant of the gene associated with high levels of MAOA (MAOA-H) and a variant associated with low levels (MAOA-L). Those with the MAOA-L variant were significantly more likely to grow up to exhibit anti social behaviour, but only if that had been maltreated as children. Children with MAOA-H variant who were maltreated and those with MAOA-L variant who had not been maltreated, did not display any anti-social behaviour
What is the ‘warrior gene’?
MAOA-L is much more frequent in populations with a history of warfare, with about two-thirds of people in these populations having this variation of the gene. By way of contrast, only about one-third os people in Western populations have this low-activity verion of the gene. This has led to it being referred to as the ‘warrior gene’. McDermott et al found that MAOA-L participants displayed higher levels of aggression (forcing a fictional participant to eat unpleasantly hot and spicy sauce), when provoked, than did MAOA-H subjects
What are the evaluation points for the genetic factors in aggression?
Problems of sampling, difficulties of determining the role of genetic factors, problems of assessing aggression, evidence for influence of MAOA gene, and the MAOA gene may explain gender differences in aggressive behaviour
How is ‘problems of sampling’ an evaluation point for the genetic factors in aggression?
Many studies in this area focused exclusively on individuals convicted of violent crime. Two particular difficulties arise when trying to draw meaningful conclusions from these studies. 1) is the participants themselves (convictions for violent crime are relatively few compared to vast number of violent attacks by individuals that never result in conviction. They therefore represent small minority of those regularly involved in aggressive behaviour) 2. Offenders designated as ‘violent’ on basis of a court conviction are not necessarily most serious/persistent offenders. Eg convicted murderer would be designated as violent for one offence despite, eg, having otherwise had a lifetime free from crime. This may explain why so many studies found little/no evidence of heritability for violence
How is ‘difficulties of determining the role of genetic factors’ an evaluation point for the genetic factors in aggression?
Connection between genetic factors and aggression is not straightforward due to problems determining what is, and isn’t a product of genetic inheritance. Difficult to establish genetic contributions to aggressive behaviour because more than one gene usually contributes to a given behaviour, as well as genetic factors there are many non-genetic (environmental) influences on manifestation of aggressive behaviour, and these influences may interact with each other-genetic factors may affect which environmental factors have an influence and vice versa (clearly demonstrated in the study by Caspi et al)
How is ‘problems of assessing aggression’ an evaluation point for the genetic factors in aggression?
Many reported studies of aggression have relied on parental or self reports of aggressive behaviour, whereas other studies have used observational techniques. In Miles and Carey met analysis, mode of assessment was found to be significant moderator of aggressive behaviour in 24 studies that made up their analysis. They found genetic factors explained large proportion of variance in aggressive behaviour in studies that had used parental/self-reports. However, those using observational ratings showed significantly less genetic contribution and greater influence of environmental factors. These inconsistencies make it hard to accurately assess the relative contributions of genetic and environmental factors in aggression
How is ‘evidence for influence of MAOA gene’ an evaluation point for the genetic factors in aggression?
In many countries, majority of all violent crime is committed by small group of persistent offenders. Recent study in Finland added research support that MAOA gene is implicated in severe violent behaviours such as murder. Tiihonen et al studied Finish prisoners, revealing MAOA-L in combination with another gene (CDH13 gene) was associated with extremely violent-behaviour. No substantial evidence for either of these genes in non-violent offenders, indicating this combination was specific for violent offending only. However, critics argue although these genes may make it harder for some people to control violent urges, they do not predetermine violent behaviour
How is ‘the MAOA gene may explain gender differences in aggressive behaviour ‘ an evaluation point for the genetic factors in aggression?
Advantage of MAOA gene research is it offers explanation for uneven rates of violence between males and females. Niehoff suggests this may be consequence of different genetic vulnerability males and females have to MAOA gene. MAOA gene is linked to X chromosome. Women have two X chromosomes, whereas men only have one. When men inherit an X-linked gene from their mothers, they are more likely to be affected by it, whereas women inheriting the same gene are generally unaffected (as they have second x chromosome with ‘normal’ gene for MAOA preventing expression of abnormal version of MAOA gene). Could explain why males typically show more aggressive behaviour than females
What are ethological explanations?
Stresses the adaptive value of animal behaviours. Ethologists study the behaviour patterns of animals in their natural environment
What does the ethological explanation state?
All members of the same species have a repertoire of stereotyped behaviours which occur in specific conditions and which do not require learning, i.e. are innate
What did ethologist Tinbergen call innate behaviours?
Fixed action patterns
What are the characteristics of fixed action patterns?
(Lea). 1. stereotyped-behaviour always occurs in same way. 2. universal-behaviour is the same in all conspecifics. 3. independent of individual experience-behaviour is innate with no learning involved. 4. ballistic-once triggered the fixed action pattern cannot be changed or stopped. 5. specific triggers-each fixed action pattern has a specific trigger (sign stimulus)
How do fixed action patterns work?
They are produced by a neural mechanism known as an innate releasing mechanism (IRM) and are triggered by a very specific stimulus known as a sign stimulus. IRM receives input from sensory recognition circuits that are stimulated by presence of sign stimulus. IRM then communicates with motor control circuits to activate (release) the fixed action pattern associated with that sign stimulus
What did Tinbergen’s research show?
His research with sticklebacks showed a male stickleback fish will produce a fixed sequence of aggressive actions when another male enters its territory. The sign stimulus in this case is not the presence of the other male, but the sight of its distinctive red abdomen that acts as the sign stimulus. If this is covered up, the intruder is not attacked
What is the ‘hydraulic model’?
Each fixed action pattern has reservoir of ‘action-specific energy’ that builds up over time. The appropriate sign stimulus causes the IRM to release this energy and animal then performs the fixed action pattern. After performing this, the reservoir of action-specific energy has built up again-this is the hydraulic model of instinctive behaviour (Lorenz’s model provides a way of visualising these various hypothetical systems)
What is ritualistic aggression?
Ethologists have shown not all aggressive behaviour involves fighting but may be ritualised in form of threat displays. Threat displays are important for contestants as they help individuals assess their relative strength before deciding to escalate a conflict. As a result, they make costly and dangerous physical aggression less likely to occur, eg male gorillas use variety of different vocalisations and gestures to intimidate an opponent without need for physical contact. Threat displays are intended to make opponent back down and are the last step before an animal either fights, or submits and leaves
What have anthropologists found about ritualistic aggression?
Have found evidence of use of ritualised aggression in tribal warfare in human cultures. Gardner and Heider described how the Dani of New Guinea engaged in highly ritualised patterns of intergroup hostility. Fox also found evidence of highly ritualised ‘fighting’ among males of the Gaelic speaking Tory island off the coast of Ireland, where threat displays appear to take the place of actual aggression
Why does Lorenz talk about wolves and doves, in regard to the ethological explanation of aggression?
Some species evolved fearsome weapons making them effective hunters. Wolves for example have powerful jaws and strong teeth. Lorenz claimed such species must also have instinctive inhibitions that prevent them using these weapons against members of their own species. When two wolves fight, if the individual who is losing submissively exposes its neck to its adversary, then instinctive inhibitions prevent the dominant animal from continuing the fight. Non-hunting species, argued Lorenz, have no such powerful natural weapons, and therefore have not developed the same inhibitions against hurting their own kind, eg when two birds (such as doves) fight, the loser can simply fly away
How did Lorenz apply the comparison between wolves and doves to the human species?
He believe the comparison had implications for the human species. He argued humans are more like the dove than the wolf when it comes to dealing with other human beings. We don’t have powerful natural weapons, like wolves do, and thus have had no need to develop strong instinctive inhibitions against killing one another. Unfortunately science and technology however has far outpaced our biological evolution, as humans have developed weapons of mass destruction without also developing instinctive inhibitions against using them
What are the evaluation points for the ethological explanation of aggression?
Criticisms of an ‘instinctive’ view of aggression, do humans have fixed action patterns for aggression?, a problem with for the hydraulic model, the benefits of ritualised aggression, and killing conspecifics is not that rare
How is ‘criticisms of an ‘instinctive’ view of aggression’ an evaluation point for the ethological explanation of aggression?
Lehrman criticised Lorenz’s instinctual explanation of aggressive behaviour. Lehrman believed Lorenz had underestimated role of environmental factors in developed of species-typical aggressive behaviour patterns. These environmental factors, largely the result of learning and experience, interact with innate factors in complex ways. Nowadays the term ‘fixed action pattern’ tends not to be used within ethology and has been replaced by ‘behaviour pattern’ to reflect they are not simply innate and can be modified by experience. Nor is behaviour as ‘fixed’ as implied by term fixed action pattern. There are subtle variations between members of same species showing the patterns are not as fixed as claimed by Lorenz
How is ‘do humans have fixed action patterns for aggression?’ an evaluation point for the ethological explanation of aggression?
Eibl-Eibesfeldt identified number of human fixed action patterns or human ‘universal’, eg smiling and the ‘eyebrow-flash’ as a sign of greeting. However, as the environment in which humans exist changes so rapidly, he suggests fixed action patterns such as aggression are no longer adaptive in modern times. Flexibility of human behaviour and ability to respond to an ever changing environment has proved more effective than the production of stereotypical, fixed patterns of behaviour. This suggests that although non-human species may respond aggressively to specific sign stimuli, human behaviour is far more varied/less predictable
How is ‘a problem with for the hydraulic model’ an evaluation point for the ethological explanation of aggression?
The issue of feedback. Lorenz argued that when levels of action-specific energy reached a critical point, this would lead to performance of fixed action pattern. This would then lead to reduction in biological energy and corresponding reduction in likelihood of aggressive behaviour. However, this argument was challenged by Von Holst who showed performance of aggressive behaviour could itself provide a further stimulus which, rather than reducing likelihood of further aggressive behaviour, made it more likely
How is ‘the benefits of ritualised aggression’ an evaluation point for the ethological explanation of aggression?
In non-human species, the main advantage of ritualised aggression is it prevents conflicts escalating into potentially dangerous physical aggression. Anthropological evidence suggests this advantage is also evident in human cultures, eg Chagnon describes how, among the Yanomamö people of South America, chest pounding and club fighting contests can settle a conflict short of more extreme violence. Similarly, Hoebel found that among Inuit Eskimos, song duels are used to settle grudges and disputes. This shows that, even in moderately to highly violent cultures such as the Yanomamö, rituals have effect of reducing actual aggression and preventing injury/death of the combatants
How is ‘killing conspecifics is not that rare’ an evaluation point for the ethological explanation of aggression?
Problem for ethological explanation of aggression concerns claim that predator species must also have instinctive inhibitions that prevent them using their natural weapons against members of own species. The argument that among such species the killing of members of same species would occur only by accident is not borne out of evidence on animal behaviour. In some predator species, the killing of conspecifics is more systematic than accidental. Eg, male lions will kill off cubs of other males, and chimpanzees will routinely kill members of another group. These findings pose challenge for ethological explanation of aggression, as cast doubt on claim that much animal aggression is ritualistic rather than real
What are evolutionary explanations?
Focus on the adaptive nature of behaviour, i.e. modern behaviours are believed to have evolved because they solved challenges faced by our distant ancestors and so became more widespread in the gene pool
What are evolutionary explanations of aggression?
An evolutionary explanation of aggression is based on the premise that the human brain is a product of evolution by natural selection. In particular, evolutionary psychologists believe that the human brain comprises a number of adaptations to cope with the various challenges associated with group living. These adaptations including those that function to inflict costs on other humans, comprise our human nature (Duntley and Buss)
How is aggression evolutionary?
Aggression is a strategy that would have been effective for solving number of adaptive problems among early humans eg gaining resources. Solving these problems enhanced survival/reproductive success of individual and as a result this mental module would spread through gene pool/ Mental modules evolved in response to particular selection pressure faced by ancestral humans. Tell us what to do in order to deal with situations similar to those faced by ancestral humans, eg aggressive thoughts and behaviours are found to increase among males when resources such as territory, mates and food are scare
How is sexual competition an evolutionary factor of human aggression?
Ancestral males seeking access to females had to compete with other males (sexual competition). One way of eliminating competition was through aggression, maybe in form of physical competition. Those individuals who used aggression successfully against competitors would have been more successful in acquiring mates so more successful in passing on genes to offspring. This would have led to development of genetically transmitted tendency for males to be aggressive towards other males
What does research say about sexual competition as an evolutionary factor of human aggression?
Puts argues various male traits seem to imply competition with other males took place among ancestral males, eg men have 75% more muscle mass than women (Lassek and Gaulin), are far more aggressive than women, and far more likely to die violently (Buss). Anthropological evidence shown that, universally, males have thicker jawbones, which Puts believes may have come from men hitting each other, with thickest-boned men surviving and passing on genes to subsequent generations. Competition with other males may also explain why males have more robust skulls and brow ridges than women
How is sexual jealousy an evolutionary factor of human aggression?
Male aggression can also occur as result of sexual jealousy, which arises as result of paternal uncertainty (Archer). Unlike women, men can never be entirely certain they are fathers of their children. As result, men are always at risk that their children may not be their own meaning the man may invest resources in offspring that are not his without being aware. The adaptive functions of sexual jealousy, therefore would have been to deter a male from sexual infidelity, so minimising risk of fathers providing for children that are not theirs
What does research say about sexual jealousy as an evolutionary factor of human aggression?
Buss suggests males have number of strategies that evolved specifically for purpose of keeping a mate. Includes use or threat of violence to prevent her from straying, as well as violence toward perceived love rival. As sexual jealousy is a primary cause of violence against women, those perceived by their partner to be threatening infidelity (eg looking at another man) may be more at risk of violence than those who are not. Studies of battered women have shown in the majority of cases, women cite extreme jealousy on part of their husbands/boyfriends as key cause of violence directed toward them (Dobash and Dobash). Dell concluded sexual jealousy accounted for 17% of all murder cases in UK
How can evolution lead to aggression in warfare
War is dangerous and costly, therefore difficult to see why an organism, selected to survive, should engage in behaviours associated with such extremes of personal cost/danger. An evolutionary explanation, therefore would lead us to expect any behaviour associated with warfare would have evolved because of adaptive benefits for individual and their offspring. Livingstone and Smith claim human warfare originated not only to obtain valuable resources but also to attract mates and forge intragroup bonds. Displays of aggressiveness/bravery are attractive to females and absence of such displays reduces attractiveness. Eg male warriors in traditional societies tend to have more sexual partners and more children. Aggression in combat can also increase status for individual warriors leading to more respect and stronger bond with the group
What are ultimate and proximate causes of aggression?
In searching for causes of human aggression, we should make distinction between proximate and ultimate causes. Social scientists may be interested in why one individual decides to attack another, or link between frustration and aggressive behaviour. These are proximate causes (things immediately responsible for particular behaviour). Evolutionary explanations concentrate on ultimate causes of behaviour (why was the aggressive behaviour so effective for early humans so that a tendency to solve problems in this way became established in the gene pool?
What are the evaluation points for the evolutionary explanations of human aggression?
Gender differences in aggression may be better explained by socialisation, aggressive behaviour may not always be adaptive, support for the link between aggression and status, gender bias in evolutionary explanations of aggression, and limitations of evolutionary explanations of aggression
How is ‘gender differences in aggression may be better explained by socialisation’ an evaluation point for the evolutionary explanations of human aggression?
Prinz argues differences in aggressive behaviour of males/females may also be product of different socialisation experiences. Eg Smetana found parents more likely to physically punish boys for bad conduct, whereas when girls misbehave parents tend to explain to them why their actions were wrong. Prinz suggests this could increase male physical violence. Girls learn they are less powerful than boys, may lead them to adopt other more social forms of aggression (eg harm another’s social status or self esteem) rather than physical aggression. This casts doubt on claim males alone have evolved aggression as way of dealing with rivals as females developed a different form of aggressive behaviour
How is ‘aggressive behaviour may not always be adaptive’ an evaluation point for the evolutionary explanations of human aggression?
Problem with seeing aggressive behaviour as effective way to meet challenges of social living is violent/aggressive behaviour can result in social ostracism, injury or death. Eg violent males may be rejected as mates, warriors may die in battle. In other words, it may be considered more maladaptive than adaptive. However Duntley and Buss point the benefits of aggression must only have outweighed costs on average relative other strategies in evolutionary past. If this is the case, then natural selection will favour evolution of aggressive behaviours, eventually making them fundamental components of human nature
How is ‘support for the link between aggression and status’ an evaluation point for the evolutionary explanations of human aggression?
Claim that increased aggression confers greater status supported by anthropological evidence that many tribal societies bestow increased status and honour men who have committed murder (Daly and Wilson). This phenomenon is also evident in industrial societies such as USA where most violent gang members often have highest status among their peers (Campbell). Males also display heightened sensitivity to perceived affronts to their status and reputation, such that many acts of male-on-male violence result from one male perceiving slight to his status from another male (Buss). Suggests not only aggression important way of gaining status among men, but is also consequence of threats to status
How is ‘gender bias in evolutionary explanations of aggression’ an evaluation point for the evolutionary explanations of human aggression?
Evolutionary explanations for physical aggression in warfare demonstrate gender bias as they don’t adequately reflect behaviour of women in this process. Adams claimed idea of women warriors is almost unheard of within most societies. Even within societies that allow women to participate in war, they are always the rare exception. Women have considerably less to fain from fighting in near certain-death situations and considerably more to lose (in terms of loss of reproductive capacity). This is fundamental to women’s exclusion from warfare, as women do not increase their fitness as much as men do. Our understanding of the physical aggressive displays typically found in warfare therefore is limited to behaviour of males rather than females
How is ‘limitations of evolutionary explanations of aggression’ an evaluation point for the evolutionary explanations of human aggression?
Explanations of aggression based on mating success, sexual jealousy or acquisition of status in warfare fail to explain levels of cruelty often found in human conflicts yet are not evident among non-human species. Eg do not explain wide-scale slaughter of whole groups as was evident in Rwandan genocide in 1994. Nor do they tell us why humans torture or mutilate opponents when they have already been defeated and no longer pose a threat. Anthropological evidence (eg Watson) suggests this may be more a consequence of de-individuation effects than of evolutionary adaptations
