Ethological Explanations of Aggression

Ethological Explanations of Aggression

1. All members of the same species have repertoire of stereotyped behaviours that occur in response to specific sign stimuli and do not require learning (FAPs)

   • These are activated by neural networks that respond to these sign stimuli (IRMs)

2. Lorenz's Hydraulic Model

   • FAP released when ASE is high enough and the appropriate sign stimulus is present

3. Humans have some FAPs, but aggressive FAPs would be maladaptive in ever-changing environment

4. Ritualistic aggression

   • Threat displays prevent escalation of conflict (gorilla's beating chest)

5. Wolves and Doves

   • Predator species have instinctive inhibitions that prevent intraspecies aggression

6. Humans are not a predator species so have no such inhibitions to prevent aggression against conspecifics

7. Evaluation

   • Criticisms of an instinctive view of aggression
     • Underestimates the role of environmental factors and variations in expression of behaviour
   • Support for Lorenz's hydraulic model
     • Stimulation of neural networks associated with FAP led to increase in aggressive behaviour
   • A problem for the hydraulic model
     • Expression of FAP should lead to decrease in aggression but may increase it
   • The benefits of ritualised aggression
     • Anthropological evidence among Yanomamo and Inuit Eskimos
   • Killing conspecifics are not that rare
     • E.g. lions and chimpanzees. Better explained by selfish gene theory