Specification: The ethological explanation of aggression, including reference to innate releasing mechanisms and fixed action patterns. Evolutionary explanations of human aggression.

Ethology 

An ethological explanation seeks to understand the innate behaviour of animals (including humans) by studying them in their natural environment. The focus of an ethological explanation is to try and account for behaviour in terms of its adaptive value to the specific species. Ethologists believe that by looking at animal behaviour this can help us to understand human behaviour. For example, a key ethologist from the attachment topic in Year 1 Psychology is Konrad Lorenz (1966) who used the behaviour of geese to explain attachment in humans. 

Aggression is also seen as providing an adaptive function by ethologists. Aggression is seen in all animal species and is believed to be an innate behaviour. If a behaviour is innate, evolutionary psychologists propose that the behaviour must be beneficial to the organism. Aggression as a behaviour can help survival, as aggression can protect resources such as land and food. Aggression can establish dominance hierarchies, and these are vital to allow access to resources, such as females. 

Lorenz (1966) proposed that aggression in animals is often ritualistic, which he argued is more adaptive than direct aggression, as symbolic aggression would help ensure the organism was not harmed. If the organism sustained an injury as part of aggression this could impair their ability to reproduce or even result in death. Therefore, ritualistic aggression such as ‘teeth baring’ would have the effect of deterring an opponent without physical harm being caused. 

Innate Releasing Mechanisms and Fixed Action Patterns 

The ethological theory proposes that aggression can be the result of an evolved automatic biological response in the brain. It is believed that animals have a built-in neural structure (a network of neurons) which, when exposed to specific stimuli (signs or releasers) such as facial expressions, will cause the release of an automatic behavioural response. 

The inbuilt biological structure or process is called the Innate Releasing Mechanism (INR). The consequential aggressive behavioural sequence is called the Fixed Action Pattern (FPA). Innate releasing mechanisms are a key part of the ethological (instinctive) approach to aggression (and other behaviours such as courtship/mating). For example, when a dog sees a cat running away from them, they have an instinctive response to chase the cat. When the cat is still the innate releasing mechanism is not activated, but when the cat runs then the INR is activated and the chasing behaviour of the dog is an example of a fixed action pattern. The dogs desire to chase is automatic and instinctual in response to a cat or any other small animal running away from it. 

Evaluation  

Tinbergen (1951) undertook an experiment with male sticklebacks. This species of fish is very territorial and aggressive. In the mating season they develop a red spot on their underside. Tinbergen observed that at this time male sticklebacks will attack another male stickleback that enters their territory. He theorised that the red spot on their underside was acting as an innate releasing mechanism and when one stickleback observed another stickleback with this red spot they would initiate the aggressive attack behaviour which is an example of a fixed action pattern. To test this out he presented male sticklebacks with a wooden model; if the wooden model had a red spot, then the male stickleback would attack. However, without the red spot the male stickleback would not react, and there was no aggression displayed.  

An ethological explanation assumes that behaviour is innate; therefore, it should be uniform across all cultures. However, Nisbett (1996) found that in a laboratory experiment when South American white males were insulted they were more likely to respond aggressively than white North American males under the same conditions. This research demonstrates cultural differences that would be problematic for the ethological explanation to account for, as there was a high variation in aggressive responses.  

There is evidence from the animal kingdom that aggression is not always ritualistic, Goodall (2010) studied chimpanzee behaviour for over fifty years. As part of her research, she observed groups of chimpanzees that waged a brutal war against neighbouring groups of chimpanzees, slaughtering all members of the group. Goodall (2010) referred to this type of gang behaviour as the systematic slaughtering of one group by another stronger group. This aggression is hard to explain from an ethological standpoint as the risk of injury to the attacking group is high and thus does not appear to be an adaptive behaviour.  

Not all fixed action patterns are fixed. There is some evidence that learning and environmental factors can create variation within a species. Therefore, it may be more appropriate to discuss modal action patterns rather than fixed action patterns. Modal action patterns are behaviours that are instinctual such as the desire to chase in dogs (the prey drive), but that differ from one individual within the species compared to others. For example, some dogs may chase cats but some dogs do not. The differences in behaviour may be down to training, or may be down to species differentiation as a result of selective breeding of characteristics. 

Evolution 

An evolutionary explanation of human behaviour examines how behaviours that were adaptive to our human ancestors are passed down through genetic transmission from one generation to the next. Behaviours witnessed today would have evolved as a reaction to the environment 10,000 to 5 million years ago. This time frame and environment is known as the Environment of Evolutionary Adaptiveness (EEA). 

Aggression in this time would have helped an individual survive, as aggression would help to secure resources, food, territory and women. These adaptive behaviours allowed our ancestors to survive and be more likely to reproduce and have more offspring. The evolutionary explanation refers to this as natural selection. In addition, the evolutionary explanation proposes that certain behaviours which confer an increased likelihood to survive will be sexually selected for by prospective mates. 

Human males would be more likely to survive if they displayed aggression as a way of protecting their mates. This behaviour would then be sexually selected for by potential females. Aggression is also a behaviour which allowed our ancestors to establish hierarchical dominance within a group. This dominance would result in higher status in the social group, which would lead to greater access to resources in general and to mates in particular. 

The evolutionary explanation also proposes that it would have been adaptive for human males to display aggression as a way of deterring other males from trying to steal their females. Females were a resource which allows transmission of genes to offspring. Sexual jealousy is more likely in males as males cannot ever be sure of paternity, whereas women can always be sure they are the child’s mother. The fear that a male may be investing their resources in another male’s offspring is called cuckoldry. Evolutionary psychologists propose that aggressive sexual jealousy would be a way of avoiding cuckoldry, and would therefore provide an adaptive function. 

Daly and Wilson (1966) have proposed that men have evolved mate-retention strategies to deter their mate from leaving or cheating because without a mate, the chance of passing on genes is reduced. Two such aggressive strategies are: 

1. Aggressive direct guarding – restricting her freedom to prevent males gaining access. e.g. stopping partners speaking and interacting with other men. 

2. Intersexual negative inducements – issuing threats of physical violence to the female if they were interested in other males 

Evaluation  

Shackleford et al. (2005) conducted a study where 107 married couples with an age range of 17-41 years-of-age were asked to fill in a questionnaire to assess their mate retention behaviours. Behaviours such as direct guarding, e.g. monopolising their partner’s time and intersexual negative inducements such as threatening to punish their partner’s infidelity were measured. The extent of male retention strategies employed by the men was significantly correlated with the extent of male directed violence towards their partners. The self-report responses of both the males and females were also found to have a significant correlation ensuring the reliability of the questionnaire. This research supports the evolutionary explanation that aggressive male mate retention strategies are used to deter females from committing infidelity.  

However, Shackleford’s research is purely correlational. We do not know that the violent aggression was a result of the male mate retention strategies and not down to another third variable. We also do not know for sure that the male mate retention strategies are an evolved behaviour and therefore innate. The behaviours demonstrated may have been a learnt behaviour rather than a biological response. Domestic violence has become far less socially acceptable than a hundred years ago; this demonstrates the effect of culture and learning on aggression. Individuals demonstrating aggressive mate retention strategies may have observed this behaviour from significant others in their lives and thus social learning could be a valid explanation for their behaviour. It is difficult to separate the effects of nature from the effects of nurture when examining aggression and mating behaviour. In addition, Shackleford’s research was based on self-report measures; therefore, issues of social desirability may come into play. In many cultures it is socially desirable for a male to display aggressive behaviours. Also Shackleford himself points out that self-report techniques suffer from issues of validity due to decay of memory over time.  

Dobash & Dobash (2000) carried out case studies of 95 women who had suffered violent abuse from their partners. As part of the case studies they used structured and unstructured interviews, gathering both quantitative and qualitative data. The main source of conflict leading to violent attacks was reported to lie with the men’s possessiveness and jealousy. An understanding of male mate retention strategies, however, does have practical applications, as the use of these strategies can alert friends and family to the potential for future violence. Relationship counselling can then be sought to intervene before the conflict escalates to physical violence. 

In addition, evolutionary explanations can be accused of being 'post hoc', an explanation that is offered thousands of years after the behaviour would have been adaptive. Human evolution has taken over 10,000 years and therefore we cannot directly observe if this aggressive sexual jealousy is actually adaptive. Fossil evidence cannot provide us with in-depth meanings behind the behaviour of our ancestors.  

The lack of directly observable evidence also means the evolutionary explanation is not falsifiable. In the aim of psychology to be viewed as a science it is preferable that theories and research are subject to the scientific process of falsification. Theories should be able to be proved wrong as well as right, yet an evolutionary explanation such as the explanation of aggression as an adaptive process against a threat of cuckoldry cannot be falsified as it is a post hoc explanation. 

Possible Exam Questions 

1. What are innate releasing mechanisms? (2 marks) 

2. What are fixed action patterns? (2 marks) 

3. For every three victims of domestic violence, two will be female, one will be male. One in four women and one in six men suffer from domestic abuse in their lifetime. Using your knowledge of evolutionary explanations of aggression, explain these statistics. (6 marks) 

4. Outline and evaluate the ethological explanation of aggression. (16 marks) 

5. Outline and evaluate the evolutionary explanation of human aggression. (16 marks)