1. Evolutionary Explanations of Human Aggression
Lesson Objective: To understand how jealousy and infidelity can influence aggressive behaviour

2. What is evolutionary psychology?
Combine ideas from evolutionary biology and neuroscience
Believe that the innate brain functioning contributes to our behaviours
We adapt to our environments
Looking at how the human brain has evolved we can explain human behaviour (ie. Aggression)

3. What is evolutionary psychology?
Evolutionary psychologists try to identify how aggression developed in the first place
Knowing the roots of aggression, we can understand about aggression in humans today
IS THIS USEFUL?

4. DEFINITIONS: match up! Ethology Benign aggression Malignant aggression
Ritualised aggression
Appeasement tactic
Behaviour that stops the aggression,
avoids injury. The animal admits defeat and
Shows submissive behaviour.
Showing of aggression for asserting power and maintaining status
Study of animal
behaviour
Similar to animal aggression,
it involves an impulsive act if threatened
An evil act which is not instinctive

5. Aggressive behaviour by ANIMALS
WHY WOULD AN
ANIMAL HAVE TO FIGHT?

6. Aggressive behaviour by ANIMALS
Animals don’t try to kill other animals
It is their aim to get their attacker to back down
LORENZ (1966) – ethologist
Four main drives:
Fear
Reproduction
Hunger
Aggression
Functions of Aggression
Only the fittest/strongest are selected as mates
Ensure survival of the young (protecting offspring)
Animals could have their own territories

7. Displays of animal aggression
Ritualised aggression – in social life and ‘tribe’
Morris (1990) animals show restraint, they often use appeasement tactics

8. Aggressive behaviour by HUMANS
Fromm (1973) states that human aggression comes in two forms:
Benign aggression (parent defending child)
Malignant aggression (gangs, genocide)
LORENZ MISSES OUT 3 BASIC THINGS
Nelson (1974)
The process of learning
Structural causes
Psychological causes

9. Aggressive behaviour by HUMANS
Infidelity and Jealousy
Daly and Wilson (1988) men have evolved strategies to deter their female partners to commit adultery
From vigilance to violence
Fuelled by jealousy
Evolved to deal with the treat of PATERNAL UNCERTAINTY

10. Infidelity and Jealousy
Cuckoldry and Sexual Jealousy
Men can never be certain that they are a father
Always at risk of cuckoldry
Might have to invest resources in children that are not theirs
Adaptive function of sexual jealousy to stop sexual infidelity

11. Infidelity and Jealousy
Male retention and Violence
Buss (1988) men have strategies to keep a mate
How??!

12. Infidelity and Jealousy
Male retention and Violence
Buss (1988) men have strategies to keep a mate
Direct Guarding
Negative Inducements

13. Infidelity and Jealousy
UX……………… (wife-killing)
Guard against infidelity either by BENEFITS or COSTS
Not all men can provide benefits, so many result to violence (costs)
Daly and Wilson (1988) death from physical violence may be an unintended outcome of an evolutionary adaptation that was designed for control

14. evolutionary instinct?
Case Study
Killers?
Victims of their
evolutionary instinct?
Pipat Lueprasitkul
Stephen Grant

15. The Evolution of Homicide
Lack of Resources
Killers – large proportion are:
Unemployed
Unmarried
Lack an ability to attract long-term mates
Is this being used as excuse?
What are the causes of murder?

16. The Evolution of Homicide
Loss of Status
Killers – defending their status in a large peer group
Loss of status is bad for survival and reproduction
Mechanisms continue to operate, triggered by events that would triggered them in our ancestral past

17. The Evolution of Homicide
Sexual Jealousy
Same-sex killings
Male-male homicide can be the result of ‘love triangles’

18. AO2
GENDER BIAS – focus on men
BLAME?
Apply to real-life

19. AO3 Correlation Case Studies
Surveys (self-report) = social desirability
Evolutionary Perspective