Ethological explanations of aggression

• Conspecifics= all members of the same species.
• FAP= Fixed Action Pattern= a collection of innate stereotyped behavioural reactions to specific situations or stimuli (sign stimulus), that are produced by a neural mechanism.
• IRM= Innate Releasing Mechanisms= the neural mechanisms that triggers a FAP- the IRM is a neural mechanism that responds to specific stimuli by initiating a FAP.
• Sign stimulus= the stimulus that activates the IRM to trigger the FAP.
• • All conspecifics share an innate response to certain stimuli, called a sign stimulus.
  • Sign stimulus activates IRM (a neural response).
  • This releases/ triggers the Fixed Action Pattern, ie the behavioural response to the stimulus.
• Example of FAP/ IRM:

  • Tinbergen showed that when a male stickleback entered another's territory, a fixed & predictable sequence of aggressive actions would ensue.
  • The sign stimulus is the red belly of the male, as when this is covered, the new male is not attacked.
• Characteristics of FAPs:

  1. Stereotyped- the behaviour always occurs in the same way.
  2. Universal- the behaviour is the same in all conspecifics.
  3. Independent of individual experience- the behaviour is innate, with no learning involved.
  4. Ballistic- once triggered, the FAP cannot be changed or stopped.
  5. Specific triggers- each FAP has a specific trigger (sign stimulus).
• Evaluation of FAP/IRM- weakness:

  • Eibl was able to identify FAPs in humans such as smiling, laughing & the universal greeting of the eyebrow flash.
  • However, FAPs relating to aggression are not common.
  • Eibl argued that as a humans' environment is so changeable & varied, a FAP as a response to a stimulus is not particularly helpful.
  • Instead, humans have evolved to be flexible in the way we respond to situations, as this is more effective in ensuring survival.
  • So although animals may have predictable FAPs to aggressive stimuli, humans are much less predictable in their behaviours.
• Ritualistic Aggression:

  • Ethologists noticed that aggressive behaviour doesn't always result in a full blown fight, and that actually the purpose of a lot of aggression displays is an attempt to avoid direct & dangerous conflict- this has resulted in many animals developing ritualistic threat displays, such as the roar of a lion.
  • These displays enable the animal to 'size up' their rival.
  • If their rival is far bigger & stronger than them, then no point fighting as you will only get hurt.
  • Only if two animals appear fairly matched, that they may need to decide the winner through fighting.
• Evaluation of ritualistic aggression- strength:

  • Ritualistic aggression can be beneficial, as it allows conflict to be settled without the need for anyone to come to harm.
  • For example, Hoebel (1967) studied Inuit Eskimos & found that they sometimes use song duels to settle disputes.
  • This example supports the theory that ritualistic aggression serves to reduce overall violence & conserve life.