Aggression as an Evolutionary Adaptation

Ethologists view aggression as an evolutionary adaptation that enables animals to protect their territory, secure resources, and compete for mates

Innate Releasing Mechanisms (IRMs)

Fixed Action Patterns (FAPs)

IRMs activate FAPs, which are highly stereotyped and species-specific behaviors that play a vital role in an animal's ability to compete for resources, defend against predators, and ensure reproductive success

Ritualized Aggression

Many species engage in ritualized aggression, such as displaying threatening postures or vocalizations, to resolve conflicts without resorting to physical violence

Lion's Aggressive Behavior During a Kill

A lion's aggressive behavior when making a kill can be contested by competing scavengers like hyenas, with the victor's tactics likely to be passed down genetically

Ritualized Aggression in Establishing Dominance Hierarchies

Ritualized aggression serves to establish dominance hierarchies and territorial boundaries, which are critical for the maintenance of social order and resource allocation

Definition of IRMs and FAPs

IRMs are prewired neural circuits that respond to specific environmental cues, triggering FAPs, which are sequences of instinctive behaviors that are typically carried out to completion once initiated

Example of IRMs and FAPs in Rhesus Monkeys

In a study by Sackett (1966), rhesus monkeys displayed defensive behaviors when presented with images of aggressive postures, suggesting the existence of an innate releasing mechanism for such responses

Konrad Lorenz

Konrad Lorenz's work on aggression highlighted its instinctual and adaptive aspects

Nikolaas Tinbergen

Nikolaas Tinbergen extended ethological concepts to include the study of various behaviors, such as the foraging patterns of honey bees