Aggression, Homicide, and Warfare - Evolutionary Psychology

Evolutionary Psychology: Aggression, Homicide, and Warfare

Syllabus and Exam Information

  • Professor William Sanderson's syllabus: www.sanderson.bz
  • Exam 3 review: Monday (1809-1882, 1859)
  • Exam Dates:
    • Exam 3: Wednesday, May 7
    • Exam 4: Wednesday, May 14, 9:00 am (finals week)

Exam 3 Review

  • Link to Exam 3 review document: https://docs.google.com/document/d/1JA
    N-Q1BFi50rFF0CNOYy-5LP4RMn048A/e
    dit
  • Aggression resources: www.sanderson.bz/aggression
  • Question from previous lecture: The tendency to be selfish in humans is best illustrated by preference for biological children.

Fantasies and Aggression

  • 91% of men and 84% of women have had at least one vivid fantasy of committing murder.
  • Most people do not act on these thoughts due to cost-benefit calculations.
  • 57% of males and females report torture scenarios as part of their romantic rejection fantasies.

Is Culture the Cause of Aggression?

  • Referenced Stanford prisoner experiment video: http://www.youtube.com/watch?v=1KXy8CLqgk4
  • Currently living in the least violent time in the history of humanity.

Genghis Khan and Historical Violence

  • Genghis Khan founded the Mongol Empire and was responsible for 20-30 million deaths.
  • 8% of men (16 million) in the region of the former Mongol empire carry a nearly identical Y-chromosome.
  • Discussion of media influence: video games, movies, music.

Konrad Lorenz on Aggression

  • Konrad Lorenz (1966) defined aggression as the fighting instinct directed against members of the same species.
  • Males are biologically programmed to fight over resources.
  • Question: Why is killing within species so much higher in humans vs other animals?
  • Murder weapon resource: http://www.sporcle.com/games/g/murderweapons
  • Murder statistics resource: http://www.infoplease.com/ipa/A0004888.html

Human Aggression as Existential Threat

  • Human aggression is considered a significant threat to the human species.
  • More than one million Americans have been killed by firearms in the US in the past 40 years.
  • This exceeds the combined U.S. combat deaths in all American wars.
  • Humans go beyond any animal in horrific aggression: torture, mass genocide.

Evolutionary Psychology Perspective on Killing

  • Donald Buss (Evolutionary Psychologist): Killing is fundamentally in our nature due to its benefits in reproductive competition.
  • Minds have developed adaptations to kill.
  • Contrary to theories suggesting murder is a pathology imposed by culture, media, poverty, or child abuse.

Homicide as Part of Human Nature

  • Homicide is the most extreme form of aggression.
  • Aggression is a significant part of human nature, not an anomaly or pathology.
  • Humans (males?) experience appetitive aggression: motivation or pleasure in acting aggressively even when non-threatened.
  • Aggression can be experienced as pleasurable (e.g., movies, sports, games). *Links:
    • http://www.askmen.com/top_10/entertainment/top-10-oscar-winning-guy-movies.html
    • http://www.ranker.com/crowdranked-list/best-chick-flicks-in-my-opinion- _

Fascination with Violence

  • Humans are fascinated with aggression/violence, especially males.
  • Reflected in society: top TV shows, movies, sports, newspapers.

Evolutionary Significance of Violence

  • What is the evolutionary significance of violence/aggression? Homicide? War?
  • What does the frequency of violence and aggression say about true human nature?
  • Are we the “noble savage” or inherently violent?
  • Males vs females: same or different?
  • If aggression is an EPM, what function does it serve?

Jane Goodall's Observation

  • In 1974, Jane Goodall observed chimpanzees making a coordinated attack on another group’s territory and killing a member.
  • This challenged the notion of “primal innocence”.
  • Humans, Chimpanzees: Two species that show intense male-initiated territorial aggression, coordinated coalitions that raid neighboring territories.
  • DNA of chimpanzees and humans: 99% alike.

Homicide Statistics

  • Who commits homicides in the US:
    • Males: 89%
    • Females: 11%
    • Spouse/significant other: males 65.5%
    • Children are the victims: males 61.8%
    • Serial killing: males 93.5%
    • Coworker: males 91.6%

Same-Sex Homicides

  • Table data showing male vs. female same-sex homicides in various locations.
  • The leading cause of violence is maleness (Wright, 1995).

Homicide Victimization Rates by Age and Sex

  • Figure showing homicide victimization rates by age and sex for the United States in 1975.
  • Evidence for the young male syndrome, in which young men entering the mating arena show the greatest degree of risk-taking and violent strategies.

Aggression as an Evolved Psychological Mechanism

  • Aggression: An Evolved Psychological Mechanism that serves as a solution to adaptive problems.

Adaptive Problems Solved by Aggression

  • What type of adaptive problems existed throughout evolution that can be solved by the use of aggression?
  • Remember: no laws, police, etc. in the evolutionary environment

Definition of Aggression

  • Aggression - hostile or violent behavior towards another person
  • Distinction: physical vs verbal aggression

Functions of Aggression

  1. Co-opting the resources of others.

    • Adult aggression: used to gain money, property (e.g., mugging, robbery, carjacking)
    • Males frequently form coalitions for the purpose of forcibly co-opting resources from others (e.g., gangs, armies)
    • How was the continental United States, from the Atlantic to the Pacific, formed?

  2. Defend against attack

    • Aggression is used prevent losing one’s resources and deter future aggressors.

  3. Inflict costs on intra-sexual rivals

    • Problem: same-sex rivals are vying for the same resources -- valuable members of the opposite sex.
    • Solution: Aggression is used to inflict costs on rivals

  4. Negotiate status and power hierarchies.

    • Aggression functions to increase one’s status or power within existing social systems.

    • Higher aggression = higher status

    • Ritualized aggression in sports such as boxing, football, hockey.

    • Aggression in business

    • War heroes – admired (given medals)

    • Gangs: initiation and status related to aggression

    • Using aggression does not elevate status in all situations and groups.

    • This implies we are sensitive to the social contexts in which aggression pays.

  5. Deter Rivals from Future Aggression

    • Individuals with a history of an aggressive reputation may deter others attempting to co-opt his resources and mates.

  6. Deter Long-Term Mates from Sexual Infidelity

    • Male sexual jealousy is the leading cause of spousal battering.

Additional Points

  • Manifest Destiny was a phrase that expressed the belief that the United States was destined to expand from the Atlantic seaboard to the Pacific Ocean.
  • Men & Women derogate their same-sex rivals attempting to lower their status and make them less desirable
  • Men sometimes kill other men who have had sex with their wives or girlfriends
  • Reminder: male killing males is highest during years they would be expected to be competing with other males for females
  • Wife Killings Most frequently related to separation:
    • 50% occurred within two months of separation
    • 85% occurred within one year of separation.
  • Another man and I are reaching for the last yogurt -- as he moves a bit ahead of me I push him as hard as I can into a wall, as he falls to the floor, I grab the yogurt. appropriate behavior?

Context Matters

  • What social contexts (under what conditions) is aggression (verbal or physical) acceptable or likely to occur in in modern society?

Willingness to Commit Homicide Study

  • Study presented more than 100 scenarios and asked people about the likelihood they would commit homicide.

  • Nearly all people express a willingness to kill in some circumstances

    • to prevent being killed
    • defend their children, kin, friends
    • protect their resources

  • Are there different “acceptable” contexts for:

    • Males against males
    • Males against females
    • Females against females
    • Females against males

Warfare

  • Male coalitional warfare is pervasive across cultures worldwide and throughout time.
  • Perhaps the most horrible thing that humans do to other humans
  • Are humans peaceful creatures in their natural state? -- the noble savage?

Yanomamo People

  • YANAMAMO in S. America observed for 35 years
    • 25,000 spread among 250 villages
    • Constant warfare: invading villages
    • ½ of all men die in warfare
    • Motivation: resources and reproduction?
      • invading members killed children
      • kidnapped and raped females

Percentage of male deaths caused by warfare

  • Chart showing various cultures and their percentage of male deaths caused by warfare.

  • 90% of hunter-gatherer societies engage in warfare

  • 64% engage in war every two years

  • Of 99 groups studied, 68 were currently at war

  • http://www.globalsecurity.org/military/world/war/index.html

Major Wars

  • The United Nations defines "major wars" as military conflicts inflicting 1,000 battlefield deaths per year.
    • 1965, 10 major wars under way.
    • 2003 - 15 major wars underway
    • Present: 8 major wars underway with as many as two dozen "lesser" conflicts ongoing with varying degrees of intensity.

Humans consume war as "entertainment"

  • Media examples: CALL-DUTY
    WAR
    ZONE, SAVING PRIVATE RYAN, FULL METAL JACKET

War and Human Nature

  • WAR IS CLEARLY PART OF HUMAN NATURE
  • “The real problem of humanity is … we have Paleolithic emotions and god-like technology. E.O. WILSON

Evolutionary Mismatch

  • EVOLUTIONARY MISMATCH IS AN ENORMOUS PROBLEM IN THE MODERN WORLD
  • Watch: Russia Tests New Missile, Putin Says "Can Hit Any Target On Earth"

Nick Bostrom's Home Page

  • Professor, University of Oxford
    *Director, Future of Humanity Institute

Implications of drones as per Lorenz?

  • Also consider Al guided drones.

Tooby and Cosmides on War

  • Tooby and Cosmides (1988) drew attention to a fact that is often overlooked: War is an intensely cooperative venture.
  • Only two species have been observed to do so: Humans, Chimpanzees
  • think of all the cooperation that has to go into fighting a war

War as a Costly Venture

  • War is an extremely costly venture for everyone involved.
  • How could evolution select for psychological mechanisms that predispose men to incur such risks?

Evolutionary Theory of Warfare

  • To wage a war:
    • The average long-term gain in reproductive resources must be sufficiently large to outweigh the reproductive costs of engaging in warfare over evolutionary time.

Economic Goals and War

  • Overthrow: America's Century of Regime Change from Hawaii to Iraq By Stephen Kinzer
    • Analysis of 14 government overthrows (or attempts) by the U.S.
    • All 14 U.S. government overthrows can be traced to economic goals (resources).

The Allure of War

  • War Is a Force that Gives Us Meaning Chris Hedges
  • “…war is an enticing elixir. It gives us resolve, a cause. It allows us to be noble.”
  • Evolution and EPAs:
    • Us against them mentality – competition for resources
    • Adaptation for fighting, aggressing
  • War creates a sense of:
    • Power
    • Righteousness
    • Group Cohesion

Presidential Approval

  • Chart showing Presidential Approval after Inauguration, 9/11, Iraq, Katrina