The Ethological Explanation of Aggression (AQA A Level Psychology)

The adaptive & ritualistic functions of aggression

• Ethology is the study of animal behaviour and, by extension, human behaviour in terms of traits, characteristics and rituals which have adapted to become useful for survival

• Aggression is an evolutionary process in that it is designed to minimise conflict and spread resources around the group (whether that be lions, monkeys, sticklebacks or humans)

• In the animal kingdom there are specific territorial behaviours which help to establish who is ‘top dog’ (quite literally!) and who must take their place further down the pecking order

• Territoriality-linked aggressive behaviour may take the form of stags rutting; male sticklebacks displaying a red underbelly as a warning to other males; a cat arching its back and hissing at other cats to ‘back off’

• Aggressive territoriality is a useful survival strategy as it results in one animal claiming rights over a specific territory which means that the rest of the group have to find alternative feeding and breeding areas which spreads the resources around and prevents overpopulation of one area (and possible starvation)

• Ritualistic behaviours are designed to show competitors who is ‘boss’ and to deter them from encroaching on the chosen territory

• Ritualistic behaviours are characterised in the following ways:

  • Little harm is actually done to each animal, the threat is implied rather than carried out to its natural conclusion i.e. death, which is ultimately damaging to the species’ survival

  • Signs of threat may include a lowered head; baring of teeth/fangs; growling/snarling; the display of red in feathers/coat/skin

  • Signs of surrender include birds turning their head towards a competitor (this is the most vulnerable part of the bird and signals the end to the fight); dogs and wolves assuming a submissive position e.g. lowering themselves down or (according to Lorenz) exposing their throat (again, the most vulnerable part of the animal)

• Human behaviour has some similarities with animal aggression e.g. wars are fought for territories; males may ‘posture’ in front of other males to warn them away from a desired female e.g. via lots of shouting, pushing, arms spread wide etc.

Who would have thought that this cute little chap is showing how dangerous he is!

Innate releasing mechanisms & fixed action patterns

• An innate releasing mechanism (IRM) is a response to a specific stimulus: the process is instinctive i.e. it does not have to be learned

• IRMs are thought to comprise a neural network in the brain i.e. they are inbuilt biological structures

• IRMs may be conspecific (signalled to members of the same species) or allospecific (signalled to animals of different species)

• Examples of IRM include:

  • Male sticklebacks signal aggression via their red underbellies: this triggers an IRM in another male stickleback who may respond by also showing aggression or by moving away from the threat (Tinbergen, 1951)

  • A dog sees a cat running away, so the dog’s IRM produces an innate response: ‘chase the cat!’

• A consequence of an IRM is a fixed action pattern (FAP) e.g. the male stickleback notices a threat so he begins a series of predetermined actions and behaviours that are designed to deter any intruders or competitors; moths fold their wings to limit ultrasonic sounds as predators use these sounds to hunt them

• FAPs tend to be: unchanging; universal across the species; stable across the species; inevitable; situation-specific; not affected by learning

Moths fold in their wings to prevent predators from detecting them: an example of a fixed action pattern.

Research which investigates the ethological explanation of aggression

• Lorenz (1970) -  the ‘founding father’ of ethological research; he first proposed IRMs and conducted various studies on animal behaviour as a guide to human behaviour

• Eibl-Eibesfeldt (1967) - neural mechanisms and social patterns of aggression in animals and humans

• Cohen et al. (1996) - threats (real or implied) were met with more aggressive responses from males from the southern states of the USA than males from the northern states i.e. there may cultural differences in aggression based on learned social norms

Evaluation of the ethological explanation of aggression

Strengths

• There is some validity to this theory from both animal and human studies (e.g. Raine et al. 1997 who found that impulsive murderers respond without thinking/instinctively to stimuli)

• Some human aggression may be as a result of genes (and hence, innate and instinctive) as seen in Brunner et al.’s (1993) study on aggression and a defective MAOA gene

Weaknesses 

• As with any research based on animal behaviour it is extremely difficult to generalise to human beings who are more cognitively and socially sophisticated and nuanced than animals

• Human researchers are not best-placed to fully understand animal behaviour; interpretations and inferences only can be drawn from the behaviour of other species

Link to Issues & Debates:

This topic fits into the nature/nurture debate as it claims that some human behaviours may be instinctive i.e. purely the result of evolution and adaptation across generations (the nature side of the debate).