The Ethological Explanation of Aggression

• What does the ethological explanation seek to understand?

  Innate behaviour of animals
• What is the main function of aggression according to the ethological explanation?

  Aggression is adaptive
• How does aggression help in social structures?

  It increases competition and establishes dominance
• Who studied the role of aggression in young children?

  Pettit et al (1988)
• What did Pettit et al (1988) observe about aggression?

  Aggression plays a role in dominance hierarchies
• What did Lorenz (1966) observe about fights between animals?

  They produced little physical damage
• What characterizes most aggressive encounters according to Lorenz?

  They consist of ritualistic signalling
• What do intra-species aggressive confrontations end with?

  Ritual appeasement displays
• What do ritual appeasement displays indicate?

  Acceptance of defeat and inhibit further aggression
• What is an Innate Releasing Mechanism?

  A biological process activated by a stimulus
• What does a Fixed Action Pattern refer to?

  A sequence of stereotyped preprogrammed behaviours
• What triggers a Fixed Action Pattern?

  An environmental stimulus activates it
• According to Lea (1984), how many main features do Fixed Action Patterns have?

  6
• What are the six main features of Fixed Action Patterns according to Lea (1984)?

  1. Stereotyped
  2. Universal
  3. Unaffected by Learning
  4. Ballistic
  5. Single-Purpose
  6. Specific Stimulus
• What was the aim of Tinbergen's (1951) study?

  To investigate sticklebacks' aggressive behaviour
• What did Tinbergen use to study sticklebacks' aggression?

  Wooden models with a red underbelly
• What behaviour did male sticklebacks display towards models with a red spot?

  They displayed aggressive behaviour and attacked
• What was the finding when there was no red spot on the model?

  No aggression was displayed
• What did Tinbergen conclude about aggressive fixed action patterns?

  They are stereotyped and triggered
• What research supports the ethological approach to aggression?

  • Brunner et al (1993): MAOA-L gene linked to aggression
  • Wilson & Daly (1996): Aggression as adaptive behaviour
  • Twin and adoption studies show genetic components
• What did Nisbett (1993) find about homicide rates?

  Reactive aggression was more common in southern US
• What cultural factor did Nisbett attribute to the difference in aggression?

  A culture of honour in the south
• What does Nisbett's conclusion suggest about aggression?

  Culture can override innate predispositions
• What did Goodall (2010) observe in chimpanzees?

  A '4-year war' between communities
• What did Goodall find about the behaviour of rival chimps?

  They killed members of another community systematically
• What challenges the ethological view according to Goodall's findings?

  Same-species aggression is not harmless
• What did Hunt (1973) point out about fixed action potentials?

  They are influenced by environmental factors
• What term do many ethologists prefer over fixed action potentials?

  Modal behaviour pattern
• How do aggressive behaviour patterns vary according to Hunt?

  They vary between individuals and encounters
• What is a strength for the Ethological Explanation of Aggression?

  Research Support

  • Brunner et al (1993) showed that the MAOA-L gene is closely associated with aggressive behaviour in humans, as well as Wilson & Daly (1996) showed that aggression is an adaptive behaviour, and therefore genetically based
  • Twin and adoption studies also showed that there is a significant genetic component to aggression in humans
  • This suggests the ethological approach is correct in claiming that aggression is genetically determined, heritable and adaptive
• What is a limitation for the Ethological Explanation of Aggression?

  External Validity

  • Nisbett (1993) found that one type of homicide as a result of reactive aggression was more common amongst white men in the southern US than in the north
  • He concluded that the difference was caused by a ’culture of honour’ in the south, showing that the aggressive behaviour comes from a learned social norm, rather than being instinctive
  • Therefore, culture can override innate predispositions, which is hard for the ethological theory to explain
• What is a limitation for the Ethological Explanation of Aggression?

  Ritualistic Aggression

  • Goodall (2010) observed a ‘4-year war’ in which male chimps from one community killed the members of another in a systematic way
  • Occasionally, a victim would be held down by rival chimps, while others beat it, despite the victims offering appeasement signals
  • This challenges the ethological view that same-species aggression has evolved into a self-limiting and relatively harmless ritual
• What is a limitation for the Ethological Explanation of Aggression?

  Fixed Action Potentials are not Fixed

  • Lorenz saw fixed action potentials as innate and unchanging, but Hunt (1973) pointed out that fixed action potentials are influenced by environmental factors and learning experiences
  • For example, the duration of each behaviour in an aggressive action potential varies between individuals, and even in the same individual depending on the encounter, resulting in many ethologists preferring the term ‘modal behaviour pattern’
  • Therefore, patterns of aggressive behaviour are much more flexible than Lorenz thought, especially in humans