The ethological explanation of aggression based on animal behaviour

Ethology is the scientific study of animal behaviour in natural settings, which can extend to human behaviour as well. Ethologists focus on specific behaviours, such as aggression, and examine them across different species.

Lorenz's theory on aggression

Konrad Lorenz, a prominent ethologist, developed a theory of aggression rooted in animal instincts, which he also applied to humans, defining aggression as an instinctive drive to fight members of the same species.

Key concepts in Lorenz's theory:

• Innate response - Aggression is an inborn trait that has evolved as an adaptive mechanism. It increases an individual's chances of survival and reproduction by helping them secure food, mates, or territory over competitors.
• Build-up and release mechanism - The drive to act aggressively accumulates over time. The longer it has been since the last aggressive act, the greater the internal urge becomes. Eventually, an environmental cue or stimulus triggers this pent-up aggression.
• Threshold for triggering - As internal pressure builds, the intensity of the stimulus needed to provoke aggression decreases. If the pressure is extremely high, aggression might occur without any apparent trigger.
• Innate releasing mechanism - A specific brain pathway, present from birth, is activated by a stimulus, leading to a fixed action pattern—a consistent, instinctive behaviour seen across a species. For instance, infants reflexively grasp objects placed in their hands.

Evidence from animal studies:

• Research on red-bellied stickleback fish supports this idea.
• During mating season, male sticklebacks, with their bright red bellies, react aggressively to the red colour on another male's underside.
• Tinbergen (1951) demonstrated that even abstract shapes painted red triggered stronger aggressive responses than real fish without red markings, highlighting the instinctive nature of this behaviour.

Lorenz suggested that most aggression is symbolic and non-lethal to prevent species extinction. For example, in wolf packs, a defeated wolf exposes its neck as a sign of submission, and the victor refrains from attacking further. In humans, Lorenz viewed activities like sports as a safe outlet for releasing aggressive instincts, reducing harmful conflict in society.

Advantages and limitations of the ethological explanation

Advantages of the ethological approach

• Support from animal behaviour - Fixed action patterns of aggression, as seen in species like stickleback fish, provide evidence that certain aggressive responses are instinctive and triggered by specific cues.
• Explanation for human violence - The theory suggests that human aggression may not have evolved to be lethal in unarmed combat. Without weapons, fights rarely resulted in death, so humans did not develop strong instincts to avoid fatal conflict. The modern use of weapons, however, increases the likelihood of deadly outcomes.

Limitations of the ethological approach

• Failure to explain premeditated aggression - This theory struggles to account for deliberate acts of violence, such as planned attacks or murders, which do not stem from immediate environmental triggers.
• Contradictory evidence on aggression release - Research by Arms et al (1979) found that viewing aggressive sports actually heightened aggression in participants rather than reducing it, challenging Lorenz's idea of sport as a harmless outlet for aggressive urges.

Evolutionary explanations of aggression as an adaptive response

Evolutionary psychology views aggression as a trait that has developed over generations to solve survival and reproductive challenges faced by our ancestors. This perspective argues that aggressive behaviour increased the likelihood of passing on genes, making it a characteristic modern humans inherit.

Adaptive functions of aggression in evolutionary terms

• Achieving status or dominance - Aggression helped individuals establish higher rank within social groups, improving access to resources and mates.
• Securing resources - Aggressive behaviour enabled individuals to claim valuable assets like territory or partners from others.
• Self-defence - Aggression served as a protective mechanism against threats to personal safety, status, or resources.
• Preventing infidelity - It acted as a deterrent to ensure long-term partners remained loyal, safeguarding reproductive success.

Critiques of evolutionary explanations

• Lack of cultural consideration - These theories often overlook variations in aggression across different cultures and individual experiences, focusing solely on biological inheritance.
• Neglect of social influences - Social and environmental factors that shape aggressive behaviour are not adequately addressed, limiting the theory's explanatory power.

Sex differences in aggression and their evolutionary basis

Evolutionary psychology also explores why aggression levels differ between males and females, linking these variations to distinct reproductive pressures faced by each sex in the past.

Evidence and explanations for sex differences

• Patterns in male aggression - Wilson and Daly (1985):
  • Examined homicide data from Detroit, finding that most perpetrators and victims were young males.
  • Of the cases linked to 'escalated showing off disputes', 29 involved male conflicts, compared to just 1 involving females.
  • Evolutionary psychologists argue that males, especially young men, evolved to be more aggressive due to intense competition for mates, as access to fertile partners was a key limit on male reproduction.
  • For females, reproduction was more limited by access to resources needed to support offspring. This led to different evolutionary pressures, resulting in less physical aggression and more focus on securing resources for survival.
• Jealousy and infidelity responses - Buss et al (1992):
  • Conducted a cross-cultural survey where participants imagined their partner becoming interested in someone else.
  • They were asked which would be more distressing: emotional attachment or sexual infidelity.
  • Results showed that 51% of men, compared to 22% of women, found sexual infidelity more upsetting.
  • This suggests men's jealousy is driven by concerns over paternity certainty, while women fear emotional infidelity due to the potential loss of resources for their children.

Evaluation of sex difference studies

• Cross-cultural consistency - The similar findings across diverse cultures in Buss et al's study imply that these jealousy responses may be innate rather than culturally learned.
• Validity concerns - The use of hypothetical scenarios and multiple-choice responses in Buss et al's research raises questions about whether the results reflect real-life behaviours or decisions.
• Challenges in testing evolutionary theories - Evolutionary explanations are difficult to prove or disprove scientifically, as they rely on historical assumptions that cannot be directly tested, making them non-falsifiable.