Ethological explanations

• Aggression is an instinct and is mostly genetically determined 

  Ethnologists study aggression in non-human animals and extrapolate their findings to humans because we're all subject to the same forces of natural selection.
• Ritualistic aggression:

  Refers to behaviours that are carried out in set order 

  Aggressive encounters involve a period of ritualistic signalling - such as displays of claws, teeth and threatening facial expressions.

  The aggressive confrontation ends with one member of the species showing acceptance of defeat such as exposing their neck as a sign of vulnerability.
• Adaptive - avoid injury:

  Avoids risking physical injury to their member of the species which could occur if they actually engaged in fighting. 

  Intra-species aggressive confrontations often end with ritual appeasement displays, to indicate defeat and to stop the victor causing any damage to the loser. 

  This is adaptive as too many deaths would threaten the existence of the species.
• Adaptive - dominance hierarchies:

  They're also adaptive behaviours as they help to establish territory and dominance hierarchies - which are vital to allow access to resources, such as females.
• Adaptive - disperse species:

  A defeated animal is rarely killed, instead they are forced to establish territory elsewhere.

  This means that members of a species spread out over a wider area and have to discover resources elsewhere - this reduces competition pressure and the possibility of starvation.
• Adaptive - establish dominance hierarchies:

  Animals that live in social hierarchies need to maintain social order.

  Aggression is used to establish and maintain status amongst others: the 'alpha male' has mating rights over females and access to food over other members of the group.
• Innate releasing mechanism:

  An innate, built-in physiological process or structure, eg: a network of neurons in the brain. 

  An environmental (sign) stimulus triggers the IRM which then releases a specific sequence of behaviours. Once triggered, these behaviours will run their course.
• Fixed action pattern (FAP)

  The specific behavioural sequence that is acted out when the IRM is triggered by a (sign) stimulus in the environment. 

  This is essentially unchangeable, and usually carried to completion once initiated.

  Eg: the way male Siamese fighting fish display a ritualised 'puffing' behaviour to make themselves more threatening to other males.
• 6 main features of FAPs

  • Stereotyped - a relatively unchanging sequence of behaviours 
  • Universal in members of the species
  • Rigid - unaffected by the experiences of the individual 
  • Ballistic - once triggered the behaviour sequence runs its course
  • Single-purpose - only occurs in a specific situation 
  • Triggered - occurs in the presence of a specific sign stimulus
• Tinbergen studied the behaviour of male sticklebacks during mating season.

  Sign stimulus = red underbelly.

  Fixed action pattern = bumping them on the nose.

  Male sticklebacks are highly territorial and develop a red spot on their underbelly. If another male enters their territory, the FAP is triggered by the sign stimulus.
• Tinbergen - method and findings:

  When models were placed in the tank with male sticklebacks, Tinbergen found that regardless of shape, the models with the red spots resulted in aggressive displays from the male fish.

  However, models with no red spots didn‘t trigger any aggressive behaviours - even if the mdoels looked like other sticklebacks.
• P - research

  If aggression is an adaptive behaviour, then research into a genetic basis for aggression can be used to support the concept of aggression as an innate instinct.
• E - research

  For example, the low activity variant of the MAOA gene has been associated with aggression.

  CDH-13 and MAOA - accounts for up to 10% of all violent crime in Finland (Tiihonen).
• E - research

  Research into activity in the limbic system (for example increased amygdala activity) suggests aggression has a neurological basis which would support the idea of an IRM.
• P - Goodall

  Observations of chimpanzees by Goodall have challenged the view of aggression as a relatively physically harmless ritual engaged in to maintain territory or status.
• E - Goodall

  Goodall reported on a '4 year war' between male chimps of different communities where chimps from one group systematically slaughtered all members of the rival group
• E - Goodall

  On some occasions, a victim was held down while others hit and bit him in an attack. The violence continued despite the victim showing signs of defencelessness and of appeasement. This is hard to explain from an ethological standpoint as the risk of injury to the attacking group is high and so it doesn’t appear to be an adaptive behaviour.
• P - animal research

  Ethological research on animals has been extrapolated to humans - problematic as it leads to an incomplete understanding of human aggression.
• E - animal research

  Lorenz didn't consider higher mammals such as primates.

  Tinbergen chose not to study the extreme destructive violence featured in human aggression.

  Despite this, both made generalisations about aggressive behaviour in humans - including warfare.
• E - animal research

  Lorenz also extrapolated from the behaviour of individual animals to the behaviour of entire countries and states

  One anthropologist points out 'war is a collective undertaking that cannot be explained by any individual impulse'