Lucrezia. Artemesia Gentilleshi.
There are limits to what is meant by the term aggression when applied to conflicts between small groups or individuals. Aggression in animals is limited to behaviour and the mechanisms underlying it. Behaviour is thus properly labelled aggressive when it is behaviour directed towards causing harm to another individual of the species. Attack is often associated with elements of self-protective and withdrawal responses. Many threat postures consist therefore of a mosaic of elements of attack and withdrawal. For convenience the term agonistic behaviour is often used to denote those threat, fleeing, and submissive elements that are associated with attack behaviour.
Aggressive behaviour is not pointless because it often results in settling disputes about status, precedence and access. Therefore, it is necessary in order to avoid confusion, to limit the term aggression to behaviour directed towards violence to others. Violence can be inflicted in various and diverse ways, not only by direct trauma – being influenced by a variety of causal factors. A further distinction to note is that aggressive behaviour is sometimes directed towards producing status or access. Obviously we can still conclude that variations in circumstances will lead to variations in behaviour.
It is agreed by some authors that since aggression arose through natural selection then it must be valuable to the species. Wynne-Edwards in particular puts forward arguments that involve the postulate that territorial aggression evolved as a part of a population control mechanism. This was aimed at keeping density below that level at which food supplies would become insufficient. The conclusion drawn from this was that animals who lost in a contest withdrew due to altruistic motives and perished in the interest of the species.
Criticism of this view includes the concept that the point is couched in human value judgements. Hinde, in criticising such a view of altruistic territorial acts, put the view that to conclude that nature would select both winners and losers was a rather slip-shod hypothesis. This was on the grounds that evolutionary forces in the past had not promoted the behaviour of both territorial winners and losers for the good of the species as a whole. Even if maintenance of population density within limits is a consequence of territorial behaviour, is an adaptation for that purpose, it is a dubious hypothesis.
Alternatively, even though losers may be doomed to perish they will stand a better chance of another opportunity if they withdrew. Withdrawal from a hopeless fight is tactful while there is a chance of gaining another territory. Thus this view postulates that natural selection operates on individuals to promote balance between aggression and a tendency to retreat. Inherently more plausible than the mechanisms of group selection propounded by Wynne-Edwards. With regard to human evolution the group selection theory cannot be applied because it neglects man’s cultural evolution which has placed him in circumstances quite different from those in which selection operated.
Other theories suggest that aggression is a benefit to a species because it ensures fitter individuals who have a priority access to food. This theory equates fitter with more aggressive. This implies not only that ‘fitter’ more aggressive individuals are those which society wishes to perpetuate but also does not equate ‘fit’ with those able to adapt. Another postulate puts the concept forward that a hierarchical structure ensures peace and order within a community, it often being said that aggression forms part of normal pleasurable human activities. It is also claimed that aggressive behaviour and fleeing responses are closely linked with sexual ones. In many instances however aggressive postures actually interfere with mating rather than promote it.
Korand Lorenz argues that only those species that show inter-individual aggressiveness show what are inter-individual bonds. Further from this he asserts that some of the best aspects of social life exist only because of their antithesis. Hinde views that evolutionary correlations between aggressiveness and social bonds are of dubious nature, and points out that the logical outcome of this hypothesis are the absurdities of Anthony Storr who claims that “…it is only when intense aggressiveness exists between two individuals that love can arise.”
There is no dispute that aggressive behaviour was selected as an adaptive characteristic in a great majority of animals. Individuals who display it to a more or less reasonable degree are more likely to survive and leave offspring than individuals who do not. This however is a completely different matter from the implication that aggression in man is a valuable character in human society. It is, as Nikko Tinbergen and others stress, always foolhardy to extrapolate from animals to man in a naïve, uncritical fashion.
In an examination of the causation of aggression it is best to note that a prime generator is the proximity of other individuals. The degree of proximity and the aggression elicited may be affected by the internal state of the individual. Worthy of note is the fact that hormonal changes can underlie the changes in aggressive behaviour. Examples can be found in birds in the breeding season, as well as those comparable fluctuations in mammalian oestrus cycles. Sometimes the internal state seems to affect the aggression by determining when and how the behaviour occurs. For example, the rank in non-breeding Weaver Finches is determined or influenced by their pituitary luteinising hormone. On a more theoretical plane concepts such as pain, fear and frustration can be advanced as causes of aggression.
Sigmund Freud put forward frustration as a major cause of aggression, his frustration/aggression hypothesis was worked out in detail by Dollard and others just prior to the war. Much of Freud’s work on aggression can be found in his book ‘Civilisation and its Discontents’ which consists of a pot pouri of views akin to the doctrine of ‘original sin’, including concepts of thanatos (drive to death) and the anti-human view of man as Homo homini lupus.
It is agreed that frustration can enhance aggression in man and though real or imaginary it can take many forms. It is dubious as to whether we can account for all aggression in terms solely relating to frustration, Again, the situation is fraught with problems of definition. There are certainly circumstances in which frustration does not accompany or cause aggression. It has been noted that pain stimuli may also produce aggression. In mice shock induced aggression is decreased by castration as well as aggression being influenced by previous social experience. Fear too is a potent stimulus. The defensive fighting of a cornered animal can be regarded as due to aggression augmented by fear, or by having its escape frustrated, or even the stimulus of an unfamiliar situation.
On occasions aggression may be directed at an individual other than the one which elicited it. Experimental and other research findings have shown that aggression may be reinforced by a number of elements, either internal or external to the animal or both. Hence we can see that aggression may have diverse causes and any one episode may depend upon multiple factors – but we can formulate the next general principles as being involved in causation proximity; aspects of internal state; frustration; pain; fear. These factors can also be seen to operate in man but require a much broader analysis and interpretation. Violence as such is much less common in nature than is supposed and it is wrong to assume that aggressive behaviour always leads to violence, though it often may. A variety of mechanisms have evolved to reduce the outcome of violence and include threat and submission postures plus territorial, hierarchical, and social systems. They all reduce violence and limit combat to an exchange of signals at a distance.
Sigmund Freud, Konrad Lorenz, and Robert Ardrey, all regarded aggression as arising from forces internal to the organism and is therefore endogenous, spontaneous, and inevitable. Thus we have the arguments of vulgar determinism. We have therefore to consider first whether aggression is always imposed by the external situation or whether organisms go and seek fights. They use the term spontaneous to mean a change in the output of a system without a corresponding change in input. Even if aggression is sometimes spontaneous it does not mean it must be inevitably so.
Such emphasis on inevitability is stressed by Lorenz, Ardrey and others when they illustrate their concept by the construction of an ‘energy’ model of motivation. As Hinde has pointed out, the controls of behaviour are infinitely more complex than any scheme that involves a unitary and centralised driving force. This is because the various aspects of a type of behaviour vary, with considerable independence, from one to another. This implies therefore that the concept that the different kinds of behaviour are all controlled in the same way is not true.
Lorenz developed his ideas by focussing on certain characteristics of aggressive behaviour that were compatible with his model. He then suppose that aggressive behaviour was virtually inevitable in the way that his model would predict. Not only was such reliance upon models inherently problematical (as game theory illustrates) but there is no value in finding facts to fit a theory when it is better to fit one’s theory to the facts.
Isolation has been demonstrated as one of the best ways of enhancing aggression in various species. Isolation induced aggression is related to a gain in weight as well as stimuli deprivation and changes in endocrine activity and changes in endocrine activity. Changes in endocrine activity would affect aggressive behaviour directly with more general affects on response and activity. This can be visualised in the view of Lorenz and others who claim that aggression is the consequence of building up aggressive energy and that this is subsequently discharged in action.
This theory is in keeping with the doctrine of catharsis. This doctrine is taken to mean an outlet of emotion afforded by drama, a purgation. This is also a popular psychiatric concept with the psychological model of the ‘coiled spring’. Again, the terms employed indicate the derivation in mechanical analysis. Recent views expressed by Berkowitz lends little support to these ideas. Although a display of anger may bring some reduction of tension.
Similar arguments are put forward about man with regard to individuals who seek fights on occasions. But some people are never involved in violence – hence we have to find out the bases for such differences. It is thus meaningless to search for the ultimate cause of aggression in either the genetic constitution of an organism or in the environment in which they develop. The characteristics of an individual result from an interaction continuously in process between the organism and its environment (as well as preceding stages of development). This is therefore part of the nature-nurture controversy of the heredity versus plasticity arguments as they are called.
These elements are readily discernible in Lewontin’s concepts of game theory application. Genes produce their effects only by virtue of the environment. Whether this is described as intra or extra organismic, the environment affects behaviour only be existing susceptibility of the organism. It may be admitted with wide agreement that consistent traits of individual differences in terms of measures of aggression can be basically genetic. From this we can safely deduce that changes in aggressive behaviour may be due to changes in sensory ability, motor activity, or locomotor activity. In some individual organisms aggression may be primarily genetic but in man the hereditary basis is probably less important that environmental stimuli.
Data obtained from experiments involving the rearing of animals in isolation shows that aggression may be affected by upbringing conditions. The effects of rearing are complex – and aggressiveness of animals may especially be affected by social status during development. This is reinforced by the observations made by Washburn and de Vore when comparing captive and wild baboons.
Experience during fighting episodes may also have a marked effect on fighting behaviour, especially where the conflict takes place with respect to an object. Subsequent aggression may be influenced markedly by the success or non-success in obtaining that object. Also the effects of the punishment on fighting in animals is complex. The probability of animals behaving in an aggressive manner in certain circumstances may be affected by their experience in the recent and remote past. It can also be seen that the performance of aggressive behaviour may itself be reinforcing – as it develops it has an acquired reinforcing value. Experience from birth onwards therefore may affect the subsequent propensity to aggression in both animals and humankind.
Such an example, albeit a weak one, can be instanced by the increasing bravado of a successful fighter until he or it meets its match. It becomes important therefore to appreciate the ways in which an individual’s potential to aggressive behaviour is affected by developmental experiences – in man this is clearly an aspect of cultural evolution.
With regard to group aggression in man we find a situation with few parallels in animals. This not only indicates that selection for aggression is an individual adaptation but that group aggression is the result of rearing conditions of the group members. Reared in conditions conducive to the development of aggressive propensities. Such factors involved in man are poverty, and deprivation of affection. Potentialities that are maintained in a chronic state of stress that are derived from real or imaginary repression may erupt because of immediate precipitating factors. The occasion becomes the incident which symbolises the more general frustrations or real underlying cause. Hence aggression may be a form of communication. Communication not only within the group but to those outside it.
Violence may only be an unfortunate sequel to a preceding performance of threat or bombast. War may sometimes exploit individual aggression, though Hinde tactfully points out that the causes be sought in other spheres, other levels of analysis – a recognition of the ways in which theories of aggression have become volatile elements of political or social theory. Aggression as behaviour that is directed towards violence towards others is not thus to be confused with ‘self-assertive’ behaviour.
Previously mentioned was the application of game theory to aggression. Maynard Smith has attempted to analyse the evolution of fighting in terms of game theory. Conventional fighting is found in man as well as animals and is a mistake to think that conventional fighting is confined just to so-called civilised societies. It is reasonable to suppose that the acceptance of conventional restraints depends upon the rationale that it is better to minimise risks in the event of defeat. The explanation that is commonly accepted for the ritual and convention of the conflicts between animals is twofold.
Firstly the individual attacks without preliminary signals will fail to find a mate for the attacker. This is satisfactory to explain the existence of ritualised courtship appeasement displays. It is not satisfactory when it is required to explain the ritualisation of conflicts over food or territory. Secondly, where there are no conventional restraints many individuals will be injured and thus will militate against the survival of the species. The conflict arises when it seems that group selection favouring conventional behaviour has individual selection operating against it. Relevant to the evolution of fighting is kinship selection. This is because individuals share many genes in common with relatives and thus increasing the survival of those relatives and genes in common. Kin selection thus reduces the severity of conflicts.
Selection also depends upon how others behave, survival depending upon competition and collaboration with other members of the species. The optimal phenotype depends on the rest of the species – usually the case with behavioural collaboration. These behavioural patterns involve communication between different individuals. This means that optimal behaviour depends on how others behave. Obviously courtship evolution implies joint evolution and joint adaptation of responses and signals. In a typical conflict situation two individuals would compete for the same resource, whether mate, territory, nest or objects.
Another conflict situation involves the choice of sex ratio of offspring. Each member desires to maximise its descendants. Hence if the rest of the population were producing males then a female producing individual will maximise the number of offspring in the form of grandchildren. Conflict would arise if individuals tried to increase their relative contribution by reducing the contribution of others. The optimal strategy in this situation depends upon the adopted strategy of others.
Game theory is concerned with conflicts and is interested in conflicts between two or more ‘players’. Essential is the existence of a conflict of interests, the tenet being that what is good for one is at least as bad for the other. Before application of the theory it is necessary to have a complete list of strategies available to each competitor. A strategy can best be described as a specification of what a competitor will do. It must also be possible to calculate the outcome of the game for every possible pair of strategies. It is also necessary to ascribe a utility to each player for each outcome – it being this ascription of utilities that becomes a major difficulty in game theory use.
Game theory was applied to evolution by Lewontin, who wanted to determine what genetic mechanisms the chances of survival of a species. His analysis postulated species versus nature. The strategies open to the species were the various genetic mechanisms it might adopt. Hence we have sexual reproduction versus asexual; polymorphous versus individual physical that is somewhat generalised in its concept – a simplistic model. Hence it can be concluded that, in regards to game theory and aggressive behaviour and fighting, when an evolutionary stable state of population exists individuals will usually fight conventionally but will escalate if opponents escalate (and occasionally escalate with provocation). Individual selection can account for the evolution of behaviour patterns which minimise injury. There is thus no need to involve group selection as an explanation.
When considering the ritualization of conflict we have to ask why animals refrain from injuring their opponents. Difficulty can arise if we fail to differentiate between conventional and ritual fighting. Ritual involves visual displays and singing. The question that arises in terms of ritual conflict is why either side should yield. Why should it, it follows, be selectively disadvantageous to continue them too long in terms of time wasting and escalation? The escalation risk is reduced because natural selection rather optimises than endangers the outcome of animal conflict.
The argument that humankind is instinctively aggressive and thus has an innate propensity to violence leads to concepts of individual and group hostility. This view, in all essentials, is Hobbesian in sentiment because it poses the situation of ‘all against all’. It is best to be reminded of the old English proverb that says “…let him make use of instinct, who cannot make use of reason.”.
May 1st 2014.