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Chapter 11: Aggression
• 1) Defining aggression.
• 2) How aggression varies across culture, gender, and individual differences.
• 3) Various theories concerning the origins of aggression
• 4) Variety of situational factors that influence when people are most likely to behave aggressively.
• 5) Important issues of media effects on aggression, and intimate violence in close relationships.
WHAT IS AGGRESSION?
• Aggression: Behaviour intended to harm another individual. This can be words or deeds; even a failure
to act can be aggressive, if that failure is intended to hurt someone. Extreme acts of aggression are
• Anger consists of strong feelings of displeasure in response to a perceived injury, including outrage,
hate, or irritation. Hostility is a negative, antagonistic attitude towards another person or group.
• Instrumental (Proactive) Aggression: Inflicting harm in order to obtain something of value, as a means
to an end. This can be for personal gain, attention, or even self-defense.
• Emotional (Reactive) Aggression: Inflicting harm for its own sake, perhaps out of frustration
CULTURE, GENDER, AND INDIVIDUAL DIFFERENCES
Culture and Aggression
• Cultures vary dramatically in how, and how much, their members aggress against each other.
Comparison Across Societies
• U.S. has very high murder rate for a politically stable, industrialized country. May be related to prevalence
and permissive attitude towards handguns. Violence more often involves individuals rather than groups.
• Americas in general have much higher crime rates than other regions, correlated with high rate of single
• Aggression levels highest in individualistic countries.
• Different attitudes towards different forms of violence, such as a husband slapping a wife. This occurs
even within the same region, due to cultural differences – e.g. Israeli Arabs and Israeli Jews.
• Different attitudes towards aggression to children: subway groping in Japan.
• Female genital mutilation: common practice in parts of Africa and Asia, considered a sacred ritual is
condemned as inhumane and dangerous in other areas.
Bullying Around the World
• Children are physically, emotionally, and sexually bullied by other students. Hidden camera and
microphones recorded 4.5 episodes of bullying/hour, with half of boys and girls saying they have bullied
• Bonta (1997): 25 societies almost completely without violence – Chewong in Malay Peninsula who do not
even have words for quarrelling, fighting, or aggression; Ifaluk of Micronesia; Amish; Hutterites;
• These societies strongly oppose competition and endorse cooperation in all aspects of their lives.
Subcultures Within a Country Page 2 of 10
• Variations in aggression as function of age, class, race, and region – young adults have much greater
rate of involvement in violent crime than any other age group.
• Most murders intraracial. African Americans face more violence: 13% of population, 49% of murder
• U.S. murder rate highest in the South, followed by the West. This may be due to a culture of honour
prevalent among white males, which encourages violent responses to perceived threats against one’s
status as an honourable, powerful man.
Gender and Aggression
• Men commit the majority of homicides, and constitute the majority of murder victims. Males are more
physically aggressive than females.
• However, aggression is all intent to harm, not just through physical means. Although boys are more
overtly aggressive, girls are more indirectly.
o Relational aggression: Indirect aggression that targets a person’s relationships and social status,
such as by threatening to end a friendship, engaging in gossip, and trying to get others to dislike
• Norms discourage females from aggressing physically, and importance of relationships to females means
injuring someone socially is more effective.
• Sexual orientation: Gay men with lower levels of physical aggression than straight men.
• Individual differences in aggression are stable longitudinally.
• Associated with aggressiveness: tendency to hold hostile cognitions, express anger, and exhibit
• Other traits associated under conditions of provocation when situations are perceived to be aversive or
o Emotional susceptibility: Tendency to feel distressed, inadequate, vulnerable to received threats
o Narcissism: Inflated sense of self-worth but without strong beliefs to support these feelings,
leaving self-esteem unstable and sensitive to criticism;
o Type A personality: Driven by feelings of inadequacy to try to prove oneself through
o Impulsivity: Relatively unable to control one’s thoughts and behaviours.
• People with high self-esteem particularly likely to aggress if they are high in narcissism, and have
received a threat to their ego (humiliation or insult).
ORIGINS OF AGGRESSION
• What is the origin of aggression? Are we born aggressive, or are we taught to be aggressive?
Is Aggression Innate?
• Innate characteristics are not dependent on learning for their development, although they can be
influenced by learning, culture, and other factors. These include evolutionary factors and biological
• Livingstone Smith (2007): Human warfare originated not only to obtain valuable resources, but also to
attract mates and forge intragroup bods. Warriors are more likely to attract mates than pacifists, so their
reproductive success would result in tendencies toward aggression and war to evolve to be part of
human nature. Page 3 of 10
• Since genetic survival is more important than individual survival, evolution favours the inhibition of
aggression towards those genetically related to us. Offspring more likely to be abused by stepparents
than biological parents.
• Men more aggressive because aggression is used to achieve and maintain status, so females will select
them for mating. Due to paternal uncertainty, sexual jealousy is more common in men; aggression helps
enhance one’s confidence in paternity.
o Male-to-male violence triggered by challenge to status or social power; male-to-female violence
triggered by sexual jealousy.
• Women primarily aggress to protect their offspring. Women thus also place a higher value on protecting
their own lives, which may be why women tend to engage in less risky relational rather than overt
• Men boost their status and successfully compete for women by direct aggression against other men,
while women boost their status through indirect aggression against other women, harming their
• Human aggressive behaviour heritable at least to some degree. This role may be stronger for physical
aggression than indirect, relational aggression.
• Twin studies: on heritable traits, monozygotic twins will be more similar than dizygotic twins, and adopted
children will resemble their biological parents more than adoptive parents.
Role of Testosterone
• Strong correlation between testosterone and aggression in animals, weaker relationship among humans.
Relationship is present in both males and females.
• Finger-length ratio of ring finger to index finger: larger ratio, especially the on right hand, is associated
with prenatal exposure to testosterone, and with higher direct aggression.
• This correlation may not be causal. In fact, successful aggression causes temporary increase in
testosterone; stress may be involved, elevating both testosterone and aggression.
• As levels of male hormones increased, female-to-male transsexuals exhibit increased aggression-
proneness. For male-to-female transsexuals who are deprived of these hormones, they experience a
Role of Serotonin
• Serotonin appears to restrain impulsive acts of aggression, so low levels of serotonin is associated with
high levels of aggression. Drugs that boost serotonin activity can dampen aggressiveness.
Brain and Executive Functioning
• Impaired prefrontal cortex processings can disrupt executive functioning, the cognitive abilities and
processes that allow humans to plan or inhibit their actions – to respond to situations in a reasoned,
flexible manner. Poor executive functioning linked to high aggression.
• Aggressive youth show different brain activity in response to watching situations in which someone
intentionally inflicts pain on another person: instead of activity associated with empathy, show activity
associated with reward. In addition, less activation in areas associated with self-regulation and moral
Is Aggression Learned?
• Aggression affected by learning: Positive reinforcement when aggression produces desired outcomes,
and negative reinforcement when aggression prevents or stops undesirable outcomes.
• Punishment most likely to decrease aggression under 3 conditions.
o 1) Immediately follows aggressive behaviour
o 2) Is strong enough to deter the aggressor Page 4 of10
o 3) Is consistently applied and perceived as fair and legitimate by the aggressor
o The certainty of punishment is more important than its severity, when the relationship between
crime and punishment is rational rather than random, as is often the case when courts and prisons
are overly busy.
• Punishment perceived as unfair or arbitrary can provoke retaliation, creating an escalating cycle. When
punishment is delivered in an angry or hostile manner, it can even offer a model to imitate.
• Corporal punishment is physical force intended to cause a child pain, but not injury, such as spanking
and hitting, for the purpose of controlling or correcting the child’s behaviour. This is correlated with
increased aggression in the child later on, as well as other antisocial behaviours and adult criminal
o Influenced by overall family environment, emotions of parent displayed during punishment, and
cultural and ethnic differences.
Social Learning Theory
• Social Learning Theory: The theory that behaviour is learned through the observation of others as well
as through the direct experience of rewards and punishments. These models influence both prosocial
behaviour and antisocial aggressive behaviour.
o Models do not need to be present – can be people on TV.
o Not only in degree of aggression, but also in kinds of aggression – specific imitations.
• People also learn aggressive “scripts” about how to behave and solve social problems, developing more
positive attitudes and beliefs about aggression. These scripts can be activated automatically.
• Gee and Leith (2007): NHL players from North America much more likely to be called for aggressive
penalties than players from Europe, who would have been exposed to fewer models of aggression and
• Early exposure to violence common to most of young violent offenders, who learn that violence is the
appropriate way to deal with conflicts and to achieve high status.
Gender Differences and Socialization: “Boys Will Be Boys”
• Gender differences in aggressive behaviour: rewarded and punished differently, and different models.
• Overt aggression more acceptable in stereotypically male roles. Boys who use aggression to deal with
conflict more likely to be rewarded with social status than girls, who suffer scorn and ridicule for fighting.
• On the other hand, girls who successfully use relational aggression reap social benefits more easily.
Girls’ attitudes about acceptability of relational aggression correlate with their mothers’ attitudes.
Culture and Socialization: Cultures and Honour
• Culture of Honour: Emphasizes male honour and social status, and the role of aggression in protecting
that honour. Even minor conflicts or disputes can be seen as challenges, and trigger aggressive
o Include: Southern U.S., traditional villages of Italy, Latin America
o Fictitious job applicant who admits he was convicted of a felony – either murdering a man who was
having an affair with his fiancée, or stealing a car to pay off debt. Employers from the South and the
West more likely to respond in an understanding way to the letter from the convicted killer than the
• Individuals in cultures of honour perceive aggressive responses to honour-based threats as the norm,
believing that others have positive attitudes towards aggression.
Nature vs. Nurture: A False Debate? Page 5 of 10
• Origins of human aggression due to an interaction of evolved mechanisms and environmental and social
SITUATIONAL INFLUENCES ON AGGRESSION
Frustration: Aggression as a Drive
• Frustration-Aggression Hypothesis by John Dollard (1939):
o 1) Frustration, which is produced by interrupting a person’s progress towards an expected goal, will
always elicit the motive to aggress
o 2) All aggression is caused by frustration
• The motive to aggress is a psychological drive, resembling physiological drives like hunger. When we
cannot directly aggress the source of our frustration due to inhibition by fear or lack of access, the
aggressive drive can seep out in displacement: aggressing against a substitute target instead of the real
• Catharsis: A reduction of the motive to aggress resulting from any imagined, observed, or actual act of
o 1) Aggression reduces level of physiological arousal
o 2) Because arousal is reduced, people are less angry and less likely to aggress further
o Therefore, displacing aggression in safer ways can be just as expensive; this includes making
hostile jokes, cursing, observing the aggression of others real or fictional, etc.
The Frustration-Aggression Hypothesis: Does the Evidence Support It?
• Frustration does not always result in aggression, and not all aggression is caused by frustration.
• Displacement may explain scapegoating reaction of blaming economic and social difficulties on
particular minority groups. However, empirical evidence inconclusive.
• Catharsis is generally accepted, but not necessarily empirically supported. It may be more
counterproductive than effective in reducing subsequent aggression:
o Imagined or observed aggression likely to increase arousal, and thus aggression – social learning
o Actual aggression can lower arousal.