Aggression - ethological explanations

• What do ethologists study?

  Behaviours shown by animals in nature
• What is the main function of aggression according to ethological explanations?

  The main function is adaptive
• How does aggression reduce competition among animals?

  Defeated animals establish territory elsewhere
• What advantage does establishing dominance provide to male chimpanzees?

  Mating rights over females
• How does aggression in playgroups affect children according to Petit et al.?

  It helps some children become dominant
• What is ritualistic aggression?

  A series of behaviours in a set order
• What is the main function of aggression according to ethological explanations?

  Adaptive
• How does aggression help reduce competition according to ethological explanations?

  A defeated animal is rarely killed but instead forced to establish territory elsewhere
• What benefit does dominance give male chimpanzees according to ethological explanations?

  Mating rights over females
• How does aggression play a role in children becoming dominant in playgroups?

  • Aggression in playgroups helps some children become dominant over others
  • This is adaptive because dominance brings benefits like access to resources (food, mates)
• What is the purpose of ritualistic aggression between members of the same species?

  To compete and establish dominance without actually harming each other
• Why is it adaptive for aggressive encounters between members of the same species to be ritualistic rather than ending in death?

  Because if every aggressive encounter ended in death, the species would go extinct
• What are the key features of fixed action patterns (FAPs) according to Lea?

  • Stereotyped (unchanging sequences of behaviours)
  • Universal (found in everyone)
  • Unaffected by learning (same for every individual)
  • Ballistic (once triggered, follows inevitable course)
  • Single purpose (behaviour only occurs in specific situation)
  • Response to an identifiable sign
• What environmental stimulus triggers the innate releasing mechanism (IRM) that leads to the aggressive fixed action pattern (FAP) in male sticklebacks?

  The red spot on the competing male's underbelly
• What did Tinbergen's study on sticklebacks show about the relationship between the IRM and FAP?

  Regardless of the shape, if the model had a red spot, the male stickleback would aggressively display and attack it. The aggressive FAP didn't change from one encounter to another.
• What gene did the Brunner et al. study show is closely associated with aggression in humans?

  MAOA-L gene
• What are the counterpoints to the ethological explanation of aggression being genetically determined and adaptive?

  • Aggressive behaviour differs across cultures, suggesting it is learned rather than innate
  • Aggression against members of the same species is not always just ritualistic, as seen in chimpanzees systematically killing members of other groups
  • Fixed action patterns (FAPs) are not as fixed as originally proposed by Lorenz, as they can be influenced by environment and learning
• What did Nisbett's study on white males from the southern vs northern US show about the role of culture in aggression?

  Southern US males were more likely to become aggressive when insulted compared to northern US males, suggesting aggressive behaviour can come from learned social norms rather than just instinct
• How did Goodall's observations of chimpanzees challenge the ethological explanation of aggression being just ritualistic?

  Goodall observed male chimps systematically and violently killing members of other groups, even when the victims offered appeasement signals that did not stop the aggression
• What do ethologists study?

  Behaviours shown by animals in nature
• What is the main function of aggression according to ethological explanations?

  The main function is adaptive
• How did Hunt's research challenge Lorenz's original view of fixed action patterns (FAPs)?

  Hunt showed that FAPs are influenced by the environment and learning experiences, making them more flexible than Lorenz's view of them as unchanging
• How does aggression reduce competition among animals?

  Defeated animals establish territory elsewhere
• What special status do dominant male chimpanzees have?

  Mating rights over females
• What role does aggression play in children's playgroups according to Petit et al.?

  Helps some children become dominant
• What is ritualistic aggression?

  A series of behaviours in a set order
• What did Lorenz observe about fights between animals of the same species?

  Produced little physical damage
• What is the purpose of appeasement displays in intra-species aggression?

  Indicates acceptance or defeat
• Why is it adaptive for species to have ritualistic aggression?

  Prevents extinction through non-lethal competition
• What does an appeasement display indicate in a wolf that loses a fight?

  It has lost the fight
• What are innate releasing mechanisms (IRM)?

  Physiological processes triggered by stimuli
• What are fixed action patterns (FAP)?

  Ritualistic, universal, ballistic behaviour patterns
• What are the six main features of FAPs according to Lea?

  Stereotyped, universal, unaffected by learning, ballistic, single purpose, identifiable sign
• How does a FAP behave once triggered?

  Follows an inevitable course to completion
• What did Tinbergen's study involve?

  Male sticklebacks and aggressive behaviours
• What was the stimulus that triggered aggressive FAP in Tinbergen's study?

  Red spot on the competing male's underbelly
• What did Tinbergen find about aggression in sticklebacks?

  Triggered by red spots, not shape
• How did Tinbergen's findings relate to FAPs?

  FAPs did not change between encounters
• What genetic evidence supports the ethological approach to aggression?

  MAOA-L gene linked to aggression
• What do twin and adoptive studies suggest about aggression?

  There is a significant genetic component