Ethological explanation

    Cards (15)

    • Ethology is the scientific and objective study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait
    • The ethological explanation states that all members of the same species have a repertoire of stereotyped behaviours which occur in specific conditions and which do not require learning. Ethologist Niko Tinbergen called these innate behaviours fixed action patterns.
    • Fixed actions patterns and innate releasing mechanisms
      1. Fixed action patterns are produced by the innate releasing mechanism and are triggered by a sign stimulus
      2. The innate releasing mechanism receives its input from sensory recognition circuits that are stimulated by the presence of the sign stimulus
      3. The innate releasing mechanism communicates with motor control circuits to release the fixed action pattern associated with that sign stimulus
    • Tinbergen (1951) stickleback fish research
      Tinbergen's research with male stickleback fish showed that a male stickleback fish will produce a fixed action pattern of aggression when another male enters its territory. The sign stimulus is the red underbelly of the fish.
      • Stickleback fish see red, this fires their innate releasing mechanism, this causes the fixed action pattern -> attack
    • Characteristics of fixed action patterns - Lea (1984)
      • Stereotyped - the behaviour always occurs in the same way
      • Universal - the behaviour is the same in all conspecifics
      • Independent of universal experience - the behaviour is innate, with no learning involved
      • Ballistic - once triggered, the fixed action pattern cannot be changed or stopped
      • Specific triggers - each fixed action pattern has a specific trigger (sign stimulus)
    • Fixed action pattern - a repertoire of stereotyped innate behaviours which occur in response to specific triggers
    • Innate releasing mechanism - a neural network, that when stimulated by a sign stimulus, communicates with motor control circuits to activate the fixed action pattern associated with the sign stimulus
    • Ritualistic aggression
      • 'Threat displays' take the place of actual aggression, they are intended to make an opponent back down
      • Anthropologists have found evidence of the use of ritualistic aggression in tribal warfare
    • The 'hydraulic model' suggests each fixed action pattern has a reservoir of 'action specific energy' that builds up over time.
      Lorenz believed that once levels of action specific energy reached a critical point, this would lead to the performance of a fixed action pattern.
      After performing the fixed action pattern, the reservoir of the action specific energy is empty and cannot be repeated until the action specific energy is built up again.
    • Hydraulic model AO3
      However Von Holst showed that the performance of an aggressive behaviour could itself provide a further stimulus, which, rather than reducing the likelihood of further aggressive behaviour, made it more likely
    • Wolves and Doves - Lorenz (1952)
      Some species (wolves) have weapons that make them hunters. They have instinctive inhibitions that prevent them from using their weapons on each other.
      Non-hunting species (doves) don't have natural weapons, so they have not developed the same inhibitions - doves will just fly away from conflict.
      Lorenz applied this to humans, he believed we are doves as we don't have natural weapons. Therefore we lack inhibition
      Unfortunately, humans have developed weapons without developing instinctive inhibitions against using them
    • Ethological aggression AO3 - criticisms of an instinctive view of aggression
      Lehrman (1953) criticised Lorenz's instinctual explanation of aggressive behaviour. Lehrman believed Lorenz had underestimated the role of environmental factors.
      Now the term 'fixed action patterns' has been replaced with 'behaviour pattern' to reflect these are not entirely innate.
      As there are subtle variations between members of the same species in the production of aggressive behaviours, this suggests that patterns of aggressive behaviour are not as fixed as Lorenz claimed.
    • Ethological aggression AO3 - humans
      Because the environment in which humans exist changes so rapidly, Eibl-Eibesfeldt suggests fixed action patterns are no longer adaptive in modern times. The flexibility of human behaviour and the ability to respond to an ever-changing environment has proved more effective than the production of stereotypical, fixed patterns of behaviour.
      This suggests that, although non-human species may respond aggressively to specific sign stimuli, human behaviour is far more varied and less predictable.
    • Ethological aggression AO3 - benefits of ritualised aggression
      In non-human species, the main advantage of ritualised aggression is that it prevents conflicts from escalating into potentially dangerous physical aggression.
      This shows that, even in moderately violent cultures, rituals have the effect of reducing actual aggression and preventing injury/death.
    • Ethological aggression AO3 - killing conspecifics is not that rare
      A problem for the ethological explanation of aggression concerns the claim that predator species must have instinctive inhibitions that prevent them using their natural weapons against members of their own species.
      The argument that among such species the killing of members of the same species would occur only by accident is not borne out by evidence on animal behaviour.