Ethological Explanation of Aggression

What is Ethology?

• The study of how the forces of evolution have adapted the behaviour of animals.

What did early ethologists do?

• They looked at wild animals in their natural environment and concentrated on these aspects of behaviour, which are inherited from one generation to the next.

What are examples of these inherited behaviours?

• Migration: Birds fly to warmer areas during winter

• Hibernation: Bears conserve enrgy during winter

Who was Konrad Lorenz? (1903 -1989)

• An Austrian zoologist, animal psychologist and ornithologist (bird expert).

• He is considered one of the founders of modern ethology.

• He worked with Tinbergen and with Karl von Frisch, they were awarded the Nobel Physiology and Medicine in 1973

What was his study?

• He studied instinctive behaviour in animals, especially in greylag geese and jackdaws.

• Working with geese he re-discovered the principle of imprinting, the learn faster from parents.

What are adaptive functions of Agression?

• It is adaptive to survival because a defeated animal is rarely killed but rather is forced to establish territory elsewhere, which reduces competition.

• Aggression establishes dominance in hierarchies.

• Eg: Male chimpanzees use aggression to cloimb their troops social heirarchy. Their dominance gives them special status like mating rights over others.

• Pettit (1988) argues this happens in humans too; that aggression played an important role in the development of some children’s dominance over others as it would be adaptive due to the benefits it brings

• Eg: power to get your own way, resources etc.

What is Ritualistic Aggression?

• Konrad Lorenz noted that since not acts of aggression leads to death.

• Ritualistic behaviours are a series of behaviours conducted in the same, set order.

• It means threatening or warning actions animals use to avoid real fighting.

What is an example of ritualistic aggression?

• Eg: After an aggressive confrontation between wolves, the loser (through an act of appeasement) will make themselves vulnerable to the victor (eg: wolves displaying their neck) as a sign of accepting defeat.

What was Tinbergen’s Research (1961)?

• He researched male stickleback that attack other males that invade its territory.

• Only males have a red belly.

• They would try to attack when they saw red.

What are the 6 features of fixed action patterns (Lea 1961) ?

• Stereotype

• Universalibity

• Independence of experience

• Ballistic

• Singleness of purpose

• Triggering stimulus

What is stereotype?

The behaviour always occurs in the same form.

What is universability?

The behaviour is found throughout the species.

What is Independance of experience?

The behaviour is not learnt

What is ballistic?

The action cannot be changed once intitiated

What is singleness of purpose?

The behaviour is used in one context only and can not be used elsewhere even if the behaviour would have been useful.

What is triggering stimulus?

The behaviour is triggered by certain know stimulus.

What is a limitating research of this theory (culture differences in aggression) ?

• There is evidence that aggressive behaviour is more common in some human cultures than in others.

• Nisbett et al (1993) found that in the US, homicide rates for white males were higher in the South than in the north due to a ‘culure of honour’ attitude

• Their response to impulsive aggression was a learnt norm.

• This was supported in a later study by Nisbett who found that when white males from the south were insulted in a research situation they became aggressive that white males from the north.

• Limitation: The ethological views aggression as instinctive therefore ethological explanations can’t explain how culture can override innate experience.

What is supporting researh of this theory?

• Research Brunner et al (1993) which showed that low activity MAOA is closely related to aggressivd behaviour in humans suggesting there is an innate basis for aggressive behaviour.

• There is also further evidence as activity in the limbic system has also shown to trigger aggressive behaviour in humans.

• Support: As the ethological explantion argues that aggression is genetically determined and heritable its validity is supported by evidence that demonstrated the genetic and physiological basis aggression.