the ethological explanation Flashcards
what is the ethological explanation?
an explanation that seeks to understand the innate behaviour of animals (including humans) by studying them in their natural environments
what are the main claims of the ecological explanation?
•it suggests the main function of aggression is adaptive
•aggression is beneficial to survival as it forces other animals to find other territories
•this means that species will spread out, reducing competition for mates and resources
•aggression establishes dominance hierarchies (dominance brings access to resources)
what are ethologists and what do they do?
ethologists observe and analyse the behaviour of animals in their natural environment (naturalistic observations). they then develop theoretical characterisations of that behaviour by considering how genetic and environmental factors interact. they consider the surgical benefit of certain behaviours.
why is aggression an adaptive feature?
•it is innate to ensure survival
•helps animal get resources
•territorially
•establish dominance hierarchies
what is an innate releasing mechanism (IRM)?
a biological structure or process which is activated by an external stimulus that in turn triggers a fixed action pattern
what is a fixed action pattern?
a sequence of stereotypes preprogrammed behaviours triggers by an innate releasing mechanism
what are the main features of a fixed action pattern?
•unchanging stereotyped sequences of behaviours
•universal- in every individual of a species
•unaffected by learning
•unstoppable- must carry on until completed
•unique to that one situation
•unique specific stimulus triggers them as a response
what was the procedure of Tinbergen’s research?
•male sticklebacks are highly territorial during the spring mating season, when they also develop a red spot on their underbelly
•if another male enters their territory, a sequence of highly stereotyped aggressive behaviours are initiated (FAPs)
•the sign stimulus that triggers the innate releasing mechanism is the sign of the red spot
•tinbergen presented sticklebacks with a series of wooden models of different shapes
what were Tinbergen’s findings?
•regardless of shape, if the model had a red spot the male stickleback would aggressively display and even attack it
•if there was no red spot, there was no aggression, even if the model looked realistically like a stickleback
•tinbergen also found that these aggressive FAP’s were unchanging from one encounter to another. once triggered, the FAP’s always ran it’s course to completion without any further stimulus
what was Sackett’s research?
•monkeys were shown pictures of other monkeys in various poses (playing, exploring, threatening)
•the monkeys were raised in isolation
•as the monkeys matured they displayed reactions to the threatening poses
•this suggests that there is an innate mechanism to detect threat, which could lead to aggressive behaviour
what is ritualistic aggression?
when animals use a range of behaviours as a warning but without engaging in actual aggression
fighting is costly for both parties as it can cause significant injury. many animals use ritualistic threat displays so they can avoid direct fighting
what are appeasement displays?
they have evolved to inhibit aggressive behaviour and reduce the damage inflicted. they prevent conflicts from going too far and causing extreme injury and death
limitation: aggression against members of the same species is not just ritualistic
•Goodall observed a ‘four year war’ during which male chumps from one community killed all the members of another group.
•they did this in a systematic way.
•the violence continued even though the victims offered appeasement signals
•these signals did not inhibit the aggressive behaviour of the attackers as predicted by the ethological explanation
•this challenges the ethological view that same-species aggression has evolved into a self-limiting and relatively harmless ritual
strength: supporting research
•Tinbergen and Sackett’s research
limitation: humans don’t have FAP’s like animals
•we can’t generalise cross species (from animals to humans)
•we don’t need to fight for resources in the same way
