1. Chapter 11
Aggression

2. Is This an Act of Aggression?
Accidentally injuring someone.
Deliberately failing to prevent harm.
Working tenaciously to try to sell a product to a customer.
Murdering for money.
Hiring someone to break a competitor’s kneecaps.
Biting someone on the neck.
Hitting others while in a rage.
Swinging a stick at someone but missing.
Hurling insults at someone.

3. What Is Aggression?
Aggression is defined as behavior that is intended to harm another individual
How do we know someone’s intentions?
Aggressive behavior can come in many different forms.

4. Language of Aggression
Violence refers to extreme acts of aggression.
Anger consists of strong feelings of displeasure in response to a perceived injury.
Hostility is a negative, antagonistic attitude toward another person or group.

5. Types of Aggression
Instrumental Aggression: Harm is inflicted as a means to a desired end.
Emotional Aggression: Harm is inflicted for its own sake.
Are these distinct categories or endpoints on a continuum?

6. Types of Aggression
Proactive aggression, whereby harm is inflicted as a means to a desired end (also called instrumental aggression).
Reactive aggression, the means and the end coincide; harm is inflicted for its own sake.

7. Culture, Gender, and Individual Differences

8. The Violent Crime Clock

9. Murder Around The World
These figures indicate the number of recorded intentional homicides per 100,000 people in each of several countries in
2010, or the most recent year for which statistics are available, according to United Nations statistics published in 2011.
Interpret the numbers with great caution, however, because there are large differences in reporting and recording practices
in the various countries, but the basic point is clear: There is wide variation in the frequency of murder around the world.

10. Murder Around The World
These figures indicate the number of recorded intentional homicides per 100,000 people in each of several countries in
2010, or the most recent year for which statistics are available, according to United Nations statistics published in 2011.
Interpret the numbers with great caution, however, because there are large differences in reporting and recording practices
in the various countries, but the basic point is clear: There is wide variation in the frequency of murder around the world.

11. Murder By World Region
Rates of recorded intentional homicides per 100,000 people in the population, in each region of the populated world.
United Nations Office of Drugs and Culture, © Cengage
Learning

12. Culture and Aggression
Cultures differ with respect to:
The forms violence typically takes
People’s attitudes toward various kinds of aggression
Individualistic vs. Collectivistic
Cultures differ in aggression involving children.

13. Nonviolent Societies

14. Bullying Around the World
One form of aggression that is prevalent across virtually all cultures is bullying.

15. Subcultures Within a Country
Aggression varies within particular societies as a function of:
Age
Class
Race
Region
Regional differences occur too

16. Gender and Aggression
Universal findings that men are more violent than women.
Differences stable over time and place.
Challenges to the notion that men are more aggressive than females.
Boys tend to be more overtly aggressive.
Girls often are more indirectly, or relationally, aggressive.

17. Gender and Types of Aggression
The results of a meta-analysis of 148 studies involving children and adolescents across several countries indicate that the magnitude and
direction of gender differences in aggression depend on the type of aggression. The height of the bars in this graph indicates the degree to
which boys show more aggression than girls; the higher the bar, the more aggression is shown by boys relative to girls. Boys tended to be much
more physically aggressive than girls, as well as to be more verbally aggressive (although this difference was smaller). Regarding indirect
aggression, however, girls tended to be more aggressive than boys. This difference was small but statistically reliable across the set of studies.
Based on Card et al., © Cengage Learning

18. Individual Differences
There are some stable individual differences in aggressiveness
Aggression in childhood
People who hold hostile conditions, express anger, and exhibit irritability tend to behave more aggressively
Other traits tend to be situational
Emotional susceptibility
Narcissism
Type A personality
Impulsivity

19. Origins of Aggression

20. Is Aggression Innate? Evolutionary Psychology
Uses principles of evolution to understand both the roots and contemporary patterns of human aggression
Emphasis placed on genetic survival rather than survival of the individual.
Accounts for inhibition of aggression against genetically related others.

21. Is Aggression Innate? Evolutionary Psychology (cont’d)
Why gender differences?
Males aggress to achieve and maintain status.
Females aggress to protect offspring.

22. Is Aggression Innate? Behavior Genetics
Is an aggressive personality type due to genes?
Mixed overall results on heritability of aggression
But trend in research supports heritability of human aggressiveness to at least some degree

23. Is Aggression Innate? The Role of Testosterone
Are there specific biological factors that influence aggression?
Strong positive correlation between testosterone levels and aggression.
But correlation is not causation!

24. Finger-Length Ratio and Military Branch in Korea
According to some research, the shorter one’s right index finger is relative to one’s right ring finger, the more “masculine” one’s finger ratio is said to be, as these ratios are thought to be associated with exposure to higher prenatal testosterone levels. This figure presents
the average ratio for a sample of men from each of four branches of the military in the Republic of Korea. The
Marines are commonly thought there to have the harshest training, and the men in this study from the Marines had
significantly lower finger-length ratios (suggesting higher levels of prenatal testosterone) than did the men from the
other branches. Tamiya et al., © Cengage Learning

25. Is Aggression Innate? The Role of Serotonin
The neurotransmitter serotonin appears to restrain impulsive acts of aggression.
Low levels of serotonin associated with high levels of aggression.
Boosting serotonin can dampen aggressiveness.

26. Is Aggression Innate? Brain and Executive Functioning
Structure of frontal lobe linked to aggression and violent behavior
Impaired prefrontal cortex in particular can disrupt executive functioning
Variance in brain activity of teens in relation to aggression

27. Brain Functioning and Aggression
This figure shows three slices of the brain. Within each slice, the areas highlighted in
color have been found in recent research to be impaired in antisocial, violent, and
psychopathic populations.
Raine, 2008.

28. Brain and Executive Functioning
In addition to hormones and neurotransmitters, the frontal lobe of the brain is implicated in the biological underpinnings of human aggression.

29. Is Aggression Learned?
Aggressive behavior is strongly affected by learning.
Aggression can be positively as well as negatively reinforced.
Positive reinforcement: Aggression produces desired outcomes.
Negative reinforcement: Aggression prevents or stops undesirable outcomes.

30. Punishment and Aggression
Punishment is most likely to decrease aggression when it:
Immediately follows the aggressive behavior
Is strong enough to deter the aggressor
Is consistently applied and perceived as fair and legitimate by the aggressor
Problems with using punishment to reduce aggressive behaviors.

31. Social Learning Theory
Behavior is also learned through the observations of others.
Bandura et al.’s (1961) inflatable doll study.

32. Social Learning Theory (cont’d)
By watching aggressive models, people:
Learn specific aggressive behaviors
Develop more positive attitudes and beliefs about aggression in general
Construct aggressive “scripts”
Nonaggressive models decrease aggressive behavior.

33. Social Learning of Aggression in Hockey
Researchers examined all the penalties called against National Hockey League players born in North America or Europe during 200 games. North American players were likely to have been exposed to more aggressive role models and positive reinforcement for fighting and aggression in hockey than their European counterparts. Consistent with this point, the results depicted here show that the North Americans were much more
likely to be called for aggressive (but not for nonaggressive) penalties than the Europeans were. Based on Gee & Leith, © Cengage Learning

34. Gender Differences and Socialization
Males and females are rewarded differently for aggression.
Also have different models
Social roles have a strong influence on gender differences in physical aggression.

35. Culture and Socialization: Cultures of Honor
Socialization of aggression varies across cultures.
e.g., Cultural differences in machismo
A culture of honor emphasizes honor and status, particularly for males, and the role of aggression in protecting that honor.
Promotes violent behavior

36. Insult, Aggression, and the Southern Culture of Honor
White male participants from either the North or South regions of the United States either were bumped and insulted by a male
confederate or they passed the confederate without incident (control condition). As you can see, the incident had a greater effect on
Southern participants. Specifically, they thought that they would be seen as less masculine (left); their testosterone levels increased
more (center); and they were slower to yield to a confederate who later approached them in a narrow corridor (right).
Cohen et al., © Cengage Learning

37. Culture of Honor and Attitudes About Domestic Violence
Participants from Chile (a culture that emphasizes honor) or Canada (a neutral culture regarding honor) listened to a tape of a man describing
his violent behavior toward his wife during a conflict. When the conflict was not triggered by an honor-related issue, Chileans and Canadians
did not differ in how acceptable they thought the violence was. When the conflict was triggered by the husband perceiving his wife flirting with
another man at a party, however, the Chileans were significantly more accepting of the violence than the Canadians were. Based on Vandello et al., © Cengage Learning

38. Nature vs. Nurture: A False Debate?
Origins of aggression not only scientific, but also political
Aggression is a profound interaction of evolved mechanisms and social factors

39. Situational Influences on Aggression

40. Frustration: Aggression as a Drive
Frustration-Aggression Hypothesis:
Frustration always elicits the motive to aggress.
All aggression is caused by frustration.
The motive to aggress is a psychological drive that resembles a physiological drive.
Can lead to displacement.
Catharsis is the reduction of this motive.

41. Frustration-Aggression Hypothesis: Does the Research Support It?
Frustration is related to aggression.
But frustration does not always produce aggressive inclinations.
There are other causes of aggression besides frustration.
Is displacement a valid concept?

42. Catharsis Viewed as a two-step sequence
Aggression reduces the level of physiological arousal.
Because arousal is reduced, become less angry and less likely to aggress further.
Sounds logical, but is it a myth?

43. Problems with Catharsis
Imagined aggression or the observation of aggressive models is more likely to increase arousal and aggression than reduce it.
Actual aggression can lower arousal levels.
But if aggressive intent remains, “cold-blooded” aggression can still occur.
Also, if it feels good, more likely to act aggressively again.

44. Problems with Catharsis (cont’d)
Feelings of hostility and anger may persist, and possibly increase.
Even relatively low levels of aggression can loosen restraints against more violent behavior.

45. Frustration-Aggression Hypothesis Revised
Frustration is but one of many unpleasant experiences that can lead to aggression by creating negative, uncomfortable feelings.
It is the negative feelings, not frustration itself, that can trigger aggression.
Negative feelings can also result from a wide variety of noxious stimuli.

46. Negative Affect Heat and Aggression Positive Affect
People lose their cool more often in hot temperatures
More violent crimes occur in summer, hotter years, and hotter cities
Positive Affect
Seems to reduce aggression

47. The Link Between Heat and Violence
Worldwide weather records and crime statistics reveal that more violent crimes are
committed during the summer than in the other seasons.
From Anderson, C.A. “Temperature and aggression: Ubiquitous effects of heat on occurrence of
human violence,” Psychological Bulletin vol 106 (pp. 74–96). Copyright © 1989 by the American
Psychological Association. Reprinted by permission.

48. Temper and Temperature in Baseball
This figure shows the average number of players hit by pitches (HBPs) per game during the 1986 through 1988 Major League
Baseball seasons. As the temperature increased, so did the likelihood that pitchers would hit batters (with balls often thrown
more than 90 miles per hour and often thrown at a batter’s head). Players’ general wildness or fatigue, as measured by
walks, wild pitches, passed balls, and errors, did not increase with temperature, suggesting that the heat–HBP correlation perhaps
was due to hotter temperatures that led to hotter tempers. From Reifman, A. S., Larrick, R. P., and Fein, S., “Temper and temperature
on the diamond: The heat-aggression relationship in major league baseball,” Personality and Social Psychology Bulletin vol 17 (p. 6). Copyright
© 1991 Sage Publications, Inc. Reprinted by permission.

49. Provocation and Social Rejection
Most aggressive incidents can be directly linked to some type of provocation, and the negative affect caused by the provocation plays a critically important role in triggering aggression.

50. Arousal: “Wired” for Action
Intensity of arousal important with regard to aggression
Excitation transfer

51. Thought: Automatic and Deliberate
Both automatic and deliberate thoughts play a critical role in aggression
Automatic cognitions
Weapons effect – tendency that the likelihood of aggression will increase by mere presence of guns
Objects associated with (a) successful aggression or (b) negative affect, serve as aggression-enhancers

52. Higher Order Cognition: Cognitive Control
Deliberate, thoughtful consideration of the situation can influence aggression.
Some people exhibit a hostile attribution bias, the tendency to perceive hostile intent in others.
Social rejection may also influence this bias

53. The Struggle for Self-Control
Alcohol, like high arousal, can impair the cognitive control of aggression.
How does alcohol increase aggression?
Alcohol reduces anxiety, which lowers inhibitions against aggression.
Intoxication causes alcohol myopia, a disruption in the way we process information.

54. The Struggle for Self-Control
Rumination involves repeatedly thinking about and reliving an anger-inducing event, focusing on angry thoughts and feelings, and perhaps even planning or imagining revenge.

55. The Path From Provocation to Aggression
Research by Thomas Denson and others (2011; Denson, DeWall, & Finkel, 2012) has shown that an anger-inducing provocation, such
as an insult or social rejection, can trigger angry rumination, which in turn reduces self-control, which in turn increases the likelihood
and severity of aggression.
Denson et al., © Cengage Learning

56. Situational Influences
Factors influencing whether one is likely to experience negative affect, arousal, and aggressive thoughts, include aversive experiences (frustration, heat, provocation), situational cues (guns, violent movies), and individual and cultural differences (chronic hostility, cultures of honor).

57. The General Aggression Model
This figure represents key aspects of an early version of the General Aggression Model (it has since been updated to include more factors, but the basics are the same). Unpleasant experiences and situational cues can trigger negative affect, high arousal, and aggression-related
thoughts. Due to individual differences, some people are more likely than others to experience these feelings and thoughts. Higher-order thinking then shapes these feelings and thoughts into more well-defined emotions and behavioral intentions. Depending on the outcome of this
thinking (which can occur beneath the individual’s conscious awareness and can be affected by factors such as alcohol or
stress), the individual may choose to aggress. From Anderson, C. A., Anderson, K. B, and Deuser, W. E., “Examining and affective framework: weapon and temperature effects on aggressive thoughts, affect, and attitudes,” Personality and Social Psychology Bulletin vol 22 (pp. 366–376). Copyright © 1996 Sage Publications, Inc. Reprinted by permission.

58. Media Effects

59. Violence in TV, Movies, Music Lyrics, and Video Games
Violence depicted in the media has been a target of attack and counterattack for decades.
If consumers didn’t enjoy violence in TV, film, music, videos, and video games, these media would not be featuring it.

60. Linking Media Violence to Real-World Violence
If you ask people whether exposure to media violence causes real aggression, most would probably say that they doubt that it does or that there has never been clear evidence one way or another on this question.

61. Copycat Violence?

62. Immediate Effects of Media Violence
Aggressive models increase aggressive behavior among children and adults.
Models can be live or on film.
Violent imagery in the music industry associated feelings of hostility and aggressive thoughts.
Playing violent video games can increase aggressive thoughts and behaviors.

63. Long-Term Effects of Media Violence
Exposure to TV violence at ages 6-9 positively correlated with aggression as adults.
No gender difference
Cross-cultural study found relationship between early viewing of TV violence and later aggression.

64. The Relationship Between Media Violence and Aggression
The correlation between exposure to violence in the media and aggressive behavior is compared here to the correlations of several other well established relationships. This comparison illustrates the relative magnitude of the link between media violence and aggressive behavior.
From Singer, D. G., and Singer, J. L., eds., Handbook of children and the media (pp. 223–254). Copyright © 2001 by Sage Publications,
Inc. Reprinted by permission of Sage Publications, Inc.

65. How Does Exposure to Media Violence Have Long-Term Effects?
Influences values and attitudes toward aggression.
Through habituation become desensitized to violence.
Depictions of violence can change values and attitudes through cultivation.

66. Violent TV Viewing and Aggression 15 Years Later
A longitudinal study tracked individuals over a 15-year
period. Based on how much TV violence they viewed as 8
year olds, individuals were categorized as having viewed
low (lower 20%), medium (middle 60%), or high (upper
20%) levels of TV violence. Their aggressiveness as adults
was measured 15 years later. For both females and males,
those who tended to watch the greatest amount of violent
TV as children tended to be the most aggressive as adults.
Based on Huesmann et al., © Cengage Learning

67. Violent Video Games as Risk Factors for Several Outcomes
A recent meta-analysis of more than 136 research papers, involving more than 130,000 participants in several countries found strong relationships between playing violent video games and a number of outcomes, including higher levels of aggressive behavior, aggressive cognition, aggressive affect, and physiological arousal, along with reduced levels of prosocial behaviors and empathy (and an associated increase in desensitization). (The sizes of the bars in this graph represent the magnitude of the relationships between violent video games and these other variables; bars in a positive direction indicate a positive relationship; bars in a negative direction indicate a negative relationship.)
Based on Anderson et al., 2010; Anderson & Prot, © Cengage Learning

68. Can Media Cause Positive, Prosocial Effects?
Early research is encouraging
Positive effect associated with prosocial television shows and children’s prosocial behavior
Some games feature positive helpful, cooperative behaviors

69. Pornography and Aggression
Positive correlation for men between exposure to pornography and reported sexually aggressive behaviors and attitudes.
But what is pornography?
Often a matter of personal opinion.
Pornography refers to explicit sexual material, regardless of its moral or aesthetic qualities.

70. Nonviolent Pornography
Arousal-affect model revisited.
Nonviolent pornography can increase men’s aggression against women.
But only when restraints that ordinarily inhibit male-to-female aggression are reduced.
Little support for direct causal link between pornography use and sexual aggression.
Though men who are predisposed to sexually offend are most likely to be affected by pornography

71. Violent Pornography
Adding violence to pornography increases possibility of harmful effects.
Brings together high arousal, negative emotional reactions, and aggressive thoughts.
Male-to-female aggression is markedly increased after exposure to violent pornography.

72. Attitudes About Sex and Aggression

73. Reducing Violence

74. Changing How We Think and Feel
Enhanced education, intelligence, and reasoning helped cause the decline in violence over the past several centuries.

75. The Decline of Violence
The homicide rates per 100,000 people per year in five regions of Western Europe from the year 1300 to 2000 are depicted in the graph on the top. These rates for England (from 1300 to 1925) and New England (from 1630–1914) are presented in the graph on the bottom.
From Pinker, S., The better angels of our nature: Why violence has declined. Copyright © 2011 by Steven Pinker.
Used by permission of Viking Penguin, a division of Penguin Group (USA) Inc. and Brockman Inc.

76. Situational and Sociocultural Factors
An improved economy, healthier living conditions, and social support are extremely important in reducing the frustration, negative affect and thinking, and provocations that fuel much aggression.

77. Multiple-Level Approaches: Programs to Prevent Violence and Bullying
One of the most successful treatment programs for violent juvenile delinquents is called multisystemic therapy (MST).
Comprehensive programs that operate on multiple levels have also proven to be effective in reducing the incidence of bullying.

78. The Olweus Bullying Prevention Program

79. Some Steps to Reduce Aggression and Violence