Ethological Explanation Flashcards
How is aggression adaptive?
Because it
- reduces competition (as animal is forced into a territory elsewhere, reducing competition pressure).
- establishes dominance hierarchies (eg a male monkey’s dominance gives him a special status, including mating rights over females).
What is ritualistic aggression?
A series of behaviours carried out in a set order. This is where aggressors the to scare their opponents but rarely become physical.
Give an example of how ritualistic behaviour is adaptive?
Intra-species aggression usually ends with an appeasement display (indicates acceptance of defeat and inhibits aggression in the winner, preventing damage in the loser).
This therefore doesn’t threaten the survival of the whole species.
What does IRM stand for?
Innate releasing mechanism
What is an IRM?
A built in physiological process or structure (e.g. network of neurones in the brain). This acts as a filter to identify threatening stimuli in the environment.
What triggers an IRM?
A sign stimulus (from the environment eg a facial expression)
What is a sign stimulus?
An external sensory stimulus which activates the IRM. This then triggers the FAP.
What is a fixed action pattern?
An instinctive pattern of behaviours, triggered by an IRM (from a sign stimulus).
It follows an inevitable course (ballistic). Is a relatively unchanging behaviour sequence (ritualistic). Also found in every individual of a species (universal).
Outline the 3 main characteristics of an FAP?
Ritualistic, universal and ballistic.
Outline the make stickleback and aggression study (Tinbergen).
PROCEDURE:
- Another male entering a Stickleback’s territory in mating sequence initiated a sequence of aggressive behaviours (FAP).
- Tinenburg presented male sticklebacks with a series of wooden models of different shapes (sign stimulus = red belly).
FINDINGS:
Red underside = aggressive display and attacks it.
No red = no aggression
Therefore, the aggressive FAP didn’t change Fromm one encounter to another; once triggered it always ran its course to completion without any further stimulus.
Give an example of ritualistic aggression?
Wolves and doves.
Outline wolves and doves as an example of ritualistic aggression.
Wolves - animals with dangerous natural weapons eg claws.
Doves - animals without natural weapons.
Wolves have been programmed to not kill each other during a fight. Eg if a wolf is losing a fight, it can expose its neck to the other wolf to surrender and it will surrender.
However doves haven’t developed this instinct - explaining why so many humans kill one another.
