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course notes


Based on the course PSY/SOC 301, taught at The Sage Colleges by Prof. Susan Cloninger. This class uses the following textbook, which provides the chapter organization that you see on the menu on the left side of this page: Myers, D. (2005). Social Psychology (8th ed.) New York: McGraw Hill.

Chapter 10: 

Aggression:  Hurting Others


Is this aggression?

  • killing others because of their ethnicity?
  • insulting the store clerk who is very slow?
  • stepping on your partner's toes while dancing?
  • eating meat?
  • accidentally bumping into someone while in line?

We can be aggressive in words, as well as deeds.

  • In fact, verbal aggression can be very subtle. We may fool ourselves into thinking we aren't aggressive.

When we hurt others, it isn't always defined as aggression. Our intentions matter.

  • physical or verbal behavior intended to hurt someone (Myers, 2005, p. 381)
  • ex: hitting someone; insulting someone

How are these types of aggression different?

  • Murdering your spouse in a violent rage?
  • Killing an enemy soldier on the battlefield?
  • aggression driven by anger and performed as an end in itself (Myers, 2005, p. 381)
  • ex: hitting or yelling at someone who has made you angry; murdering out of rage
  • aggression that is a means to some other end (Myers, 2005, p. 381)
  • ex: killing someone to steal his money
  • ex: killing as your job (a soldier)
  • What about "road rage"?


  • Is aggression inborn?
  • Is aggression a response to frustration?
  • Is aggression learned social behavior?

Aggression as biology

  • Instinct theory and evolutionary psychology
  • Neural influences
  • Genetic influences
  • Biochemical influences

Instinct theory and evolutionary psychology


  • an innate, unlearned behavior pattern exhibited by all members of a species
  • ex: animals fighting over territories; possibly human "death instinct" (Freud), but that is controversial

Instinct theories of aggression


  • Thanatos = "death instinct" directed toward others


  • "fighting instinct" disperses populations over wide areas, maximizing use of available resources


  • aggression as part of the evolutionary process because it was adaptive

Neural influences

  • electrical stimulation of the amygdala produces rage

Genetic influences

  • selective breeding of mice and other animals for aggressiveness
  • sympathetic nervous system activity
  • temperament
  • twins are similar

Biochemical influences

  • alcohol unleashes aggression (in people who are provoked)
  • high levels of testosterone
  • low levels of serotonin makes one violence-prone

Men with higher levels of testosterone:

  • research on 1709 men aged 40 to 70 years (Salvadore, 1997)
  • are less pleased with life (more sad)
  • are less optimistic about the future
  • report getting less emotional support from family and friends
  • have double the divorce rate of men with low testosterone
  • are aggressive

Low serotonin levels are associated with

  • hyperresponsiveness to aversive stimuli

an integrated model (Bernhardt, 199) [graphic presented in lecture]

Aggression as a response to frustration

drive theory: external conditions, such as frustration, give rise to a motive to hurt others

What makes you angry? Many people (such as 1000 Swedish teenagers studied by Torestad, 1990) describe frustrating situations:

  • Source: Kenrick et al, Social Psychology, p. 360
  • thwarted plans (e.g., my parents don't allow me to go out in the evening)
  • environmental frustrations ("I go to see a film listed in the paper, but when I get there it isn't playing.")


  • anything that blocks our attaining a goal
  • ex: broken vending machine

Frustration isn't always expressed directly against the person (or thing) that caused the frustration. In fact, it may be dangerous to do so.


  • the redirection of aggression to a target other than the source of the frustration (generally to a safer or more socially acceptable target)
  • ex: kicking the dog or yelling at a child instead of at your boss

Frustration-aggression theory revised

  • reasons for frustration (such as broken hearing aid) reduce aggression
  • ANGER may be essential

revised frustration-aggression theory (graphic) [frustration leads to anger, which in turn leads to aggression]

In addition, stimuli and the availability of aggressive responses must be considered.

  • stimuli: sight of weapons (gun) increases aggression
  • banning handguns reduces murder rate

the "weapons effect"

  • Weapons (such as guns) enhance aggressive thoughts and feelings. In an experiment by Berkowitz & LePage, Ss made angry and then tested in a room with a 12-gauge shotgun and a .38 caliber revolver, gave longer and stronger shocks to a supposed fellow S w

Is frustration the same as deprivation?

  • No. The gap between expectations and attainments is crucial.

Does money alleviate frustration

  • The adaptation-level phenomenon

Adaptation-level Phenomeonon

  • the tendency to adapt to a given level of stimulation and thus to notice and react to changes from that level
  • ex: noticing increase or decrease from your current level of income (or gpa, etc.)

Relative deprivation

  • the perception that one is less well off than others to whom one compares oneself
  • ex: Air Force members' greater dissatisfaction when more of their fellow officers were promoted; frustration when economy improves and others do better than oneself

Who would you expect would have higher self-esteem: high ability students who attend elite schools, or those attending less elite schools?

  • Why?
  • What would the concept of relative deprivation predict?
  • Marsh & Parker (1984): "Is it better to be a relatively large fish in a small pond even if you don't learn to swim as well?"

social learning theories: aggression is viewed as a learned social behavior that can be altered

Aggression as learned social behavior

The rewards of aggression

children; hockey players; rioting

Observational learning

Bandura's social learning theory

  • Bobo doll study
  • the family: physical punishment, absent fathers
  • the subculture


Aversive incidents


  • displacement in shocked rats and other species
  • aversive stimuli lead to aggression


  • laboratory studies: more irritation and hostility (e.g., more horn-honking at stalled driver)
  • real world: more riots and crimes in hot weather (including assaults, wife-beatings, rapes, murders, and urban riots)


  • intentional attacks breed retaliation


post-exercise arousal

Schachter and Singer's study

In Ss not told about the physiological effects:

  • epinephrine + euphoric model produce euphoria
  • epinephrine + angry model produce anger

Schachter & Singer: Angry Group, HappyGroup [graphic presented in lecture]

Aggression Cues


Media influences: Pornography and sexual violence

Distorted perceptions of sexual reality

Aggression against women

  • correlates with availability of (violent) pornography
  • is widespread (22-28%, in some surveys, report rape or attempted rape)
  • 1/3 men might rape if they could get away with it
  • rape myths

Media awareness education

Items from the Burt Scale (Rape Myths)

  • "A woman who goes to the home or apartment of a man on their first date implies that she is willing to have sex."
  • "Any healthy woman can successfully resist a rapist if she really wants to."
  • "Many rapes are invented by women who have discovered they are pregnant and want to protect their own reputation."

Media influences: Television

Television's effects on behavior

  • Correlating TV viewing and behavior
  • TV viewing experiments
  • Why does TV viewing affect behavior


  • positive, constructive, helpful social behavior (the opposite of antisocial behavior)
  • ex: helping someoneWhat are the consequences of aggression, and of its alternatives? We've learned aggression because it has been rewarding. We learn to respond to stimuli that trigger aggression. We can learn something else instead.

Television's effects on thinking


Altered perceptions

Cognitive priming

t is estimated that most Americans view 200,000 acts of violence on TV before they finish high school.

  • That's over 30 per day!
  • If you take out 8 hours for sleeping, that's an act of violence every 32 minutes!!!! (If the TV were on for 16 hours a day.)

We learn how to behave.

TV doesn't make all who watch it aggressive.

According to one researcher (Wendy Wood), 13% of those exposed to a violent program will become more aggressive than usual.

Media Influences: Video Games

The games kids play

Effects of the games kids play

Group Influences

diffusion of responsibility

social "contagion"

social identity (gangs)

collective mentality leading to genocide

experiments: groups can amplify aggression



  • Would he be less aggressive if he screamed? [graphic presented in lecture]
  • emotional release
  • ex: aggressive action or fantasy that reduces the aggressive drive (a controversial proposal!)
  • catharsis: "letting off steam"

A social learning approach

Change effects of television.

  • Provide different models.
  • Tell children that TV is unrealistic. (Inoculate them.)
  • Provide family models that are not aggressive.


supplementary material presented in lecture:


  • The risk of being murdered in the United States is 7 to 10 times that in most European countries. Finland is the closest European competitor, but the American homicide rate is 3 times that of Finland.

The "culture of honor" among southern White males

  • a study by Cohen et al, 1996, Journal of Personality and Social Psychology, 70(5), 945-960
  • "Insult, Aggression, and the Southern Culture of Honor: An 'Experimental Ethnography'"
  • "For centuries, the American South has been regarded as more violent than the North ..."
  • "culture of honor": need to defend self against insults, or else will lose status before family & peers


  • U. Michigan students who grew up in the North or South; white males only
  • insulted by a confederate, who bumped into the participant and called him an "asshole"


    • Northerners were relatively unaffected
    • Southerners were affected in many ways

    Southerners were:

    • more likely to think their masculine reputation was threatened
    • more upset (rise in cortisol levels, a hormone associated with stress, anxiety, and arousal in humans & animals)
    • more physiologically primed for aggression (rise in testosterone levels)
    • more cognitively primed for aggression
    • more likely to engage in aggressive and dominant behavior (not yielding in narrow hallway; "chicken" game analogy)
    • more likely to think their masculine reputation was threatened
    • more upset (rise in cortisol levels, a hormone associated with stress, anxiety, and arousal in humans & animals)
    • more physiologically primed for aggression (rise in testosterone levels)
    • testosterone levels rose 12% for insulted Southerners (4% for control, not insulted)
    • rose 6% for insulted Northerners (4% for control)
    • more cognitively primed for aggression
    • 35% of Northerners, but 85% of Southerners, became angry (according to observers)
    • 65% of Northerners, but only 15% of Southerners, reacted by being amused at the "you asshole" insult
    • more likely to engage in aggressive and dominant behavior (not yielding in narrow hallway; "chicken" game analogy)

    The Seville Statement on Violence

    • 1986, by scientists from 12 nations meeting in Seville, Spain
    • It is scientifically incorrect to say that we have inherited a tendency to make war from our animal ancestors. Warfare is a peculiarly human phenomenon and does not occur in other animals.
    • It is scientifically incorrect to say that war or any other violent behavior is genetically programmed into our human nature. Except for rare pathologies the genes do not produce individuals necessarily predisposed to violence. Neither do they determine the opposite.
    • It is scientifically incorrect to say that in the course of human evolution there has been a selection for aggressive behavior more than for other kinds of behavior. In all well-studied species, status within the group is achieved by the ability to cooperate and to fulfill social functions relevant to the structure of that group.
    • It is scientifically incorrect to say that humans have a "violent brain." While we do have the neural apparatus to act violently, there is nothing in our neurophysiology that compels us to.
    • It is scientifically incorrect to say that war is caused by an "instinct" or any single motivation. The technology of modern war has exaggerated traits associated with violence both in the training of actual combatants and the preparation of support for war in the general population.
    • We conclude that biology does not condemn humanity to war, and that humanity can be freed from the bondage of biological pessimism. Violence is neither our evolutionary legacy nor in our genes. The same species that invented war is capable of inventing peace.

    There are sex differences in aggression. Males commit the majority of violent crimes. In 1991, males committed about 90% of homicides in the US. Changes in sex role norms over time have not changed this sex difference.

    However, women are also aggressive.

    • Women are as high as men in reporting that they feel angry.
    • Women also are physically aggressive against their intimate partners. (Some studies suggest they're more physically aggressive against their partners than are men.)
    • Girls are more likely to use indirect aggression: hurting others through gossiping, spreading vicious rumors, and rejecting people socially.

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    Ch. 1: Introduction
    Ch. 2: Self
    Ch. 3: Beliefs
    Ch. 4: Attitudes
    Ch. 5: Culture
    Ch. 6: Conformity
    Ch. 7: Persuasion
    Ch. 8: Groups
    Ch. 9: Prejudice
    Ch. 10: Aggression
    Ch. 11: Attraction
    Ch. 12: Helping
    Ch. 13: Conflict
    Ch. 14: Clinic
    Ch. 15: Court
    Ch. 16: Future