Lesson 4- Ethological explanations of aggression Flashcards
ethological explanation of aggression
-seeks to understand the innate behaviour of animals by studying them in their natural environment, focus on adaptive value to species
-aggressiom is seen as providing adaptive function by ethologists, seen in all animals believed to be innate, must be beneficial to organism
-behaviour that can help survival as aggression can protect resources such as land and food, can establish dominance hierarchies, vital to allow access to other resources such as mates
Lorenz 1966 and aggression
-proposed aggression in animals is often ritualistic, argued more adaptive than direct aggression, as symbolic aggression would help ensure organism was not harmed
-if organism sustained injury as part of aggression could impair ability to reproduce/death, ritualistic sggression would have effect of deterring opponent without physical harm being caused
ethiological x biological
-proposed aggression can be a result of an evolved automatic biological response in the brain, believed animals have a built in neural structure which when exposed to specific stimuli will cause the release of an automatic behavioural response
-inbuilt biological structure/process- Innate Releasing Mechanism (network of neurons in the brain)
-an environmental stimulus triggers IRM which then releases a specific sequence of behaviours- Fixed Action Pattern (FAP)
ethiological x biological
-proposed aggression can be a result of an evolved automatic biological response in the brain, believed animals have a built in neural structure which when exposed to specific stimuli will cause the release of an automatic behavioural response
-inbuilt biological structure/process- Innate Releasing Mechanism (network of neurons in the brain)
-an environmental stimulus triggers IRM which then releases a specific sequence of behaviours- Fixed Action Pattern (FAP)
-key part of approach, other examples include mating
FAP main features
-Lea 1984
Stereotyped- unchanging sequences of behaviour
Universal- same behaviour is found in every individual of species
Unaffected by learning- same for every individual regardless of experience
Ballistic- once behaviour is triggered it follows an inevitable course and cannot be altered before completed
Single purpose- only occurs in specific situation and not any others
Response to identifiable specific sign stimulus, or involves communication between members of same species- releaser
ethological evaluation
-Tinbergen 1951, male sticklebacks, very territorial and aggressive species, develop red spot on underside in mating season, observed that during this time will attack another male that enters their territory, theorised red spot acted as IRM and would cause initiation of aggressive attack FAP, presented wooden model, if had a red sport they would attack, without they would not react no aggression
-assumes behaviour is innate therefore should be uniform across all cultures
-Nisbett 1996, lab experiment, when South American males were insulted they were more likely to respond aggressively than white North American males under same conditions, cultural differences problematic for approach to account for, high variation
-Goodall 2010, studied chimpanzee behaviour for over 50 years, part of observed groups of chimpanzees that waged brutal war against neighbouring groups slaughtering all members, referred to this type of gang behaviour as systematic slaughtering of a group by a stronger one, hard to explain as risk of injury from attacking group is high and does not appear to be adaptive
-not all FAP are fixed, some evidence that learning and environmental factors can create variation within a species, more appropriate to discuss modal action patterns- behaviours that are instinctual but differ from one individual in species compared to others, differences may be down to training or species differentiation as a result of selective breeding
