Ethology is the study of animals in their natural environments within the context of evolutionary theory.
Ethologists study animals in their natural habitats and there is no distinction between humans and animals. An assumption is made that humans and animals share many similar drives so what is found in animals is also the same for humans.
Innate releasing mechanisms
IRMs are biologically hard-wired mechanisms for aggression ( brain structures or neural pathways for aggression). Environmental cuestrigger the innate releasing mechanism. This releases an FAP
Fixed Action Patterns
aggressive behaviours within a species often follow set patterns known as fixed action patterns. These patterns are universal across the species and once they are initiated the animal will keep going until the behaviour is complete