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to each other. The major predators of humans are other humans.

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Violence at political rallies, terrorism, and horrifying workplace shootings bewilder us, but they shouldn't. Traditional approaches to understanding violence seem played out. What we need is an understanding of violence at the level of brain circuitry. Violence, like all human behavior, is controlled by the brain. From the everyday road rage, to domestic violence, to a suicide bombing, the biology of anger and aggression is the root cause of most violent behavior.

Viewing violence narrowly from the perspective of psychological dysfunction shirks the larger truth that the biological roots of rage exist in all of us. The leading risk of death throughout the prime of life is not disease. It is violence. If you survive into old age you will most likely die from disease, but according to CDC statistics for deaths in the United States for the year 2014, life ends at the hand of another human so frequently, that from early childhood through middle-age, homicide is the third to 5th most common cause of death in all age brackets between 1-44 years.

A psychopath or a foreign terrorist is not the likely villain. The data show that the murderer is twice as likely to be your friend or acquaintance as it is to be a stranger. Deadly violence against oneself (suicide) is second only to accidental injury as the most frequent way we die between the ages of 10 and 34.

The most important factor in violence is not pathology, psychology, or politics-- it is biology. Nine out of ten people in prison for violent crime are men. Males die from homicide at three times the rate of women. When the victim is a spouse or intimate partner women are murdered at 3.3 times the rate of men. Males commit suicide at four times the rate of females. Violence and maleness is a biological fact that runs through the vast diversity of cultures and through our ancestral tree to other primates.

We have neural circuits of rage and violence because we need them. As a species we needed deadly violence to obtain food, to protect ourselves, our family, our group, and unfortunately we still need them today. Order in society is maintained through violence, meted out methodically by police and nations according to laws that benefit society at large, but this organized violence is founded on the same neurocircuitry of aggression wired into the human brain of every individual.

We are on the brink of a new understanding of the neuroscience of violence. Like detectives slipping a fiber optic camera under a door, neuroscientists insert a fiber optic microcamera into the brain of an experimental animal and watch the neural circuits of rage respond during violent behavior. Neurons genetically modified to flash bursts of light when they fire reveal where these circuits of rage are in the brain, and neuroscientists can stimulate or squelch the firing of a neuron they target by laser beam. With the flip of a switch neuroscientists can launch an animal into a violent attack or arrest a violent battle underway by activating or quelling the firing of specific neurons in the brain's rage circuits. Technological advances in monitoring brainwaves and brain imaging are bringing new insight into this same circuitry at work in the human brain. These circuits of aggression are part of the brain's threat detection mechanism embedded deep in the unconscious region of the brain where sex, thirst, and feeding are also controlled. Struggling to comprehend a suicide bomber's "thinking" or police searching for "motives" in cases where violence is driven by perceptions of threat, alienation or emotion is a search in vain. Such violence is not driven by reason. It is driven by rage.

Our current perspective views violence as pathology and seeks to find common elements that unite all violent behavior. "The different forms of violence- child abuse and neglect, youth violence, intimate partner violence, sexual violence, elder abuse and suicidal behavior-are interconnected and often share the same root causes," the CDC concludes in its strategic vision statement. But lumping together all forms of violence in an attempt to find a common denominator has created the incomprehensible muddle we find ourselves in today, as we struggle to comprehend a school shooting, or worshipers slaughtered inside a church by racial hatred. The sickening violence of Sandy Hook, which was the product of a broken mind, cannot be lumped together with the violence of the terrorists in San Bernardino, or violence committed in a robbery, or the everyday violence of barroom brawls, domestic violence, or deadly road rage. Each of these violent acts can be understood as specific behaviors that are controlled, as are all behaviors, by specific circuits in the brain activated by specific triggers.

Most of the time the neural circuits of aggression are life-saving, as when a mother instantly reacts aggressively to protect her child in danger, but sometimes they misfire and violence explodes inappropriately, as in a road rage shooting. The pressures of modern life constantly press on these triggers of rage. International communication and high-speed transportation increase opportunities for conflict between different groups of people. Weapons of violence amplify the lethal effects of one enraged mind well beyond the power of any individual to combat with bare hands. Add to this the toxic effects of psychoactive drugs for treating mental illnesses and drugs of abuse, compounded by the increasing stress, crowding, and sensory bombardment of the modern world, and we see the human brain struggling to cope with an environment it was never designed to confront.

We cannot hope to control violence if we are bewildered by it. The CDC statistics strongly suggest that in addition to understanding the biological basis of disease, there is a much greater unmet need for neuroscience research to understand the biological underpinnings of violent behavior. We cannot change the biology of our brain, but if we choose to, we can comprehend it at the same level of detail that we comprehend the biology of a human heartbeat.

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Violence at political rallies, terrorism, and horrifying workplace shootings bewilder us, but they shouldn't. Traditional approaches to understanding violence seem played out. What we need is an understanding of violence at the level of brain circuitry. Violence, like all human behavior, is controlled by the brain.

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In psychology, aggression refers to a range of behaviors that can result in both physical and psychological harm to yourself, others, or objects in the environment. Aggression centers on hurting another person either physically or mentally.

While we all may feel aggressive on occasion, when aggression becomes pervasive or extreme, it may be a sign of an underlying mental health condition, a substance use disorder, or another medical issue.

Aggression can serve a number of different purposes, including:

Expressing anger or hostility

Asserting dominance

Intimidating or threatening

Achieving a goal

Expressing possession

Responding to fear

Reacting to pain

Competing with others

Signs of Aggression

Because aggressive behavior is intended to harm someone who doesn't want to be harmed, it must involve action-simply thinking about harming someone or feeling angry isn't enough, and accidentally harming someone doesn't qualify. Aggressive behaviors can be:

Physical, like beating, hitting, kicking, or stabbing another person. Damaging property is also a form of physical aggression.

Verbal, which may include mocking, name-calling, and yelling.

Relational, which is intended to harm another person's relationships. This can include spreading rumors and telling lies about someone else.

Passive-aggressive, like ignoring someone during a social event or offering back-handed compliments. Passive-aggressive behavior is usually intended to allow harm to come to someone, rather than causing harm directly.

While we often think of aggression in its physical forms, psychological aggression can also be very damaging. Intimidating or verbally berating another person, for instance, are examples of verbal, mental, and emotional aggression. Cyberbullying is another form of non-physical aggression that can cause serious harm to others.

Types of Aggression

Psychologists divide aggression into two main types. Both are damaging to those who experience them, whether as the target or the aggressor.

Impulsive Aggression

Also known as affective or reactive aggression, impulsive aggression is characterized by strong emotions. Impulsive aggression, especially when it's caused by anger, triggers the acute threat response system in the brain, involving the amygdala, hypothalamus, and periaqueductal gray.

This form of aggression is not planned and often takes place in the heat of the moment. If another car cuts you off in traffic and you begin yelling and berating the other driver, you're experiencing impulsive aggression.

Instrumental Aggression

Also known as predatory aggression, instrumental aggression is marked by behaviors that are intended to achieve a larger goal. Instrumental aggression is often carefully planned and usually exists as a means to an end.

Hurting another person in a robbery is an example of this type of aggression. The aggressor's goal is to obtain money, and harming another individual is the means to achieve that aim.

We don't know precisely what causes excessive or inappropriate aggression. It's likely that several different factors are involved, including someone's biology, environment, and psychological history.

Biological Factors

There may be genetic and hormonal factors that influence aggression. Imbalances in certain hormones, like testosterone and cortisol, and neurotransmitters, like serotonin and dopamine, may be linked to aggression. These imbalances can occur for a number of reasons, including genetics.

Brain structure can also influence aggression. People with structural abnormalities in the amygdala tend to show more aggression than their peers. Changes in other areas of the brain may also contribute to aggressive behavior.

Environmental Factors

How you were raised may play a role in whether or not you engage in aggressive behavior. People who grow up witnessing aggression may be more likely to believe that violence and hostility are socially acceptable. Experiencing trauma during childhood can also lead to aggressive behavior in adulthood.

Psychologist Albert Bandura's famous Bobo doll experiment demonstrated that observational learning can also play a role in how aggression develops. In this experiment, children who watched a video clip where an adult model behaved aggressively toward a Bobo doll were more likely to imitate those actions when given the opportunity.

Psychological Factors

Several mental health conditions can be associated with aggressive behavior, including:

Epilepsy, dementia, psychosis, substance use disorder, and brain injuries or abnormalities can also influence aggression.

Impact of Aggression

Aggression can affect your health and relationships. Research suggests that there is a link between anger and chronic inflammation, which can cause secondary health problems like cardiovascular issues. Anger and aggression are also associated with mental health conditions. However, it isn't clear if unregulated anger causes those conditions, or if the conditions themselves make it difficult to manage intense emotions like anger and aggression.

Experiencing aggression at the hands of a partner, friend, or family member also has detrimental effects. People who have been victims of physical or psychological aggression view those experiences as harmful, even when their aggressor doesn't. These forms of aggression can ultimately lead to the end of the relationship.

Unchecked aggression can also make things more difficult at work and strain friendships. That can lead to more stress and feelings of alienation for the aggressor, which may worsen the problem.

Help With Managing Aggression

If you're experiencing feelings of aggression, you can learn to manage your anger and cope in a more constructive way. Developing an anger management plan ahead of time can give you a roadmap to use when your emotions feel out of control. That plan should include ways to reduce your stress levels, like:

Being mindful of your anger warning signs, like clenching your jaw, a fast pulse, or sweating

Practicing relaxation techniques like deep breathing, meditation, or progressive muscle relaxation (PMR)

Engaging with your senses by focusing on things you can see, smell, hear, touch, or taste

Walking away from the situation

Exercising to burn off excess energy

Reaching out to a trusted friend or family member for social support

Distracting yourself with another activity

Reframing negative thoughts

Learning to explore and accept the emotions underlying the aggression

If someone in your life is behaving aggressively toward you, it's important to protect your own mental health and physical safety. Try to stay calm and avoid escalating the conflict, and walk away if it's safe to do so. If you're facing aggression at the hands of an intimate partner, look out for warning signs that the relationship is becoming dangerous, and reach out for help and support.

Frequently Asked Questions

Which part of the brain controls aggression?

Aggression involves several different regions of the brain. The amygdala, hypothalamus, and periaqueductal gray are involved in recognizing an acute threat and generating an emotional response, while the prefrontal cortex plays a role in whether or not we act based on those emotions.

What is passive aggression?

Passive aggression is a way to express aggression indirectly. This kind of behavior is still intended to harm others, but it's often harder to identify and address. Deliberately avoiding someone else or "forgetting" to complete assigned tasks can be examples of passive-aggressive behavior.

What is reactive aggression?

Reactive aggression, also known as impulsive aggression, happens in response to a specific trigger. This form of aggression isn't planned and is often associated with feelings of intense anger. Hitting someone in response to an insult is an example of reactive aggression.

What is microaggression?

Microaggressions are subtle behaviors that discriminate against a marginalized group of people. Microaggressions can be intentional or they may reflect someone's implicit bias; either way, they can have a cumulative, negative effect on the person being targeted.

What is the goal of aggression?

The goal of aggression is to harm someone who doesn't want to be harmed. The motivation behind this varies from person to person. Someone may act aggressively as a response to pain or fear, while someone else may use aggression to achieve another goal, like taking another person's money or property.

A Word From Verywell

Aggression is often the byproduct of another underlying factor. Exploring and addressing that root cause can often help reduce aggressive behavior.

If you're troubled by aggression, seeking professional mental health care may benefit you. Anger management classes can help you learn how to avoid responding to intense emotions and how to manage aggression in a healthy, safe way.

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Aggression is forceful and hostile behavior toward another person that can result in emotional or physical harm. Learn about different types of aggression.

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Biological and Emotional Causes of Aggression

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Biological and Emotional Causes of Aggression

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Learning Objectives

1. Explain how aggression might be evolutionarily adaptive.

2. Describe how different parts of the brain influence aggression.

3. Summarize the effects of testosterone and serotonin on aggression.

When we see so much violence around us every day, we might conclude that people have an innate tendency, or even an instinct, to be aggressive. Some well-known philosophers and psychologists have argued that this is the case. For instance, the philosopher Thomas Hobbes (1588-1679) took this view, arguing that humans are naturally evil and that only society could constrain their aggressive tendencies. On the other hand, the philosopher Jean-Jacques Rousseau (1712-1778) was more positive. He believed that humans are naturally gentle creatures who are aggressive only because we are taught to be so by our society. The influential psychologist Sigmund Freud, who lived through the disaster of World War I in which millions of his fellow human beings were massacred, argued that although people do have a "life instinct," they also have a "death instinct"-an impulse toward destruction of themselves and others.

Is Aggression Evolutionarily Adaptive?

A belief in the innate aggressive tendencies of human beings-that the ability to be aggressive toward others, at least under some circumstances, is part of our fundamental human makeup-is consistent with the principles of evolutionary psychology. After all, the goal of maintaining and enhancing the self will in some cases require that we prevent others from harming us and those we care about. We may aggress against others because it allows us to gain access to valuable resources such as food and desirable mates or to protect ourselves from direct attack by others. And we may aggress when we feel that our social status is threatened. Therefore, if aggression helps with either our individual survival or in the survival of our genes, then the process of natural selection may well cause humans, as it would any other animal, to be aggressive. Human beings need to be able to aggress in certain situations, and nature has provided us with these skills (Buss & Duntley, 2006). Under the right situation, almost all of us will aggress.

However, just because we can aggress does not mean that we will. It is not necessarily evolutionarily adaptive to aggress in all situations. For one, aggressing can be costly if the other person aggresses back. Therefore, neither people nor animals are always aggressive. Rather, they use aggression only when they feel that they absolutely need to (Berkowitz, 1993a). In animals, the fight-or-flight response to threat leads them sometimes to attack and sometimes to flee the situation. Human beings have an even wider variety of potential responses to threat, only one of which is aggression. Again, the social situation is critical. We may react violently in situations in which we are uncomfortable or fearful or when another person has provoked us, but we may react more calmly in other settings. And there are cultural differences, such that violence is more common in some cultures than in others.

There is no doubt that aggression is in part genetically determined. Animals can be bred to be aggressive by breeding the most aggressive offspring with each other (Lagerspetz & Lagerspetz, 1971). Children who are aggressive as infants also are aggressive when they are adults (Coie & Dodge, 1998; Dubow, Huesmann, & Boxer, 2003; Raine, 1993) and identical twins are more similar than fraternal twins in their aggressive tendencies and criminal records. Behavioral genetics studies have found that criminal and aggressive behavior is correlated at about .70 for identical twins but only at about .40 for fraternal twins (Tellegen et al., 1988).

Avsalom Caspi and his colleagues (2002) found evidence for the person-by-situation interaction in determining aggression. They focused on the the influence of a particular genetic factor, the monoamine oxidase (MAOA) gene, located on the X chromosome, that produces an enzyme that influences the production of serotonin, a neurotransmitter that influences mood, appetite, and sleep and that inhibits aggression. Supporting the role of genetics in aggression, they found that individuals who had lower levels of activity of this gene were more at risk to show a variety of aggressive behaviors as adults. However, they also found that the genetic factor was only important for children who had also been severely mistreated. This person-by-situation interaction effect is shown in Figure 9.4. Although much more research is needed, it appears that aggressive behavior, like most other behaviors, is affected by an interaction between genetic and environmental variations.

Caspi and his colleagues (2002) found evidence for a person-by-situation interaction regarding the role of genetics and parental treatment in aggression. Antisocial behavior and aggression were greater for children who had been severely maltreated, but this effect was even stronger for children with a gene variation that reduced the production of serotonin.

Evolutionary principles suggest that we should be less likely to harm those who are genetically related to us than we are to harm others who are different. And research has supported this finding-for instance, biological parents are much less likely to abuse or murder their own children than stepparents are to harm their stepchildren (Daly & Wilson, 1998, 1999). In fact, these researchers found that preschool children living with a stepparent or foster parent were many times more likely to be murdered by their parent than were children who lived with both biological parents.

The Role of Biology in Aggression

Aggression is controlled in large part by the area in the older part of the brain known as the amygdala ( Figure 9.5, "Key Brain Structures Involved in Regulating and Inhibiting Aggression"). The amygdala is a brain region responsible for regulating our perceptions of, and reactions to, aggression and fear. The amygdala has connections with other body systems related to fear, including the sympathetic nervous system, facial responses, the processing of smells, and the release of neurotransmitters related to stress and aggression.

In addition to helping us experience fear, the amygdala also helps us learn from situations that create fear. The amygdala is activated in response to positive outcomes but also to negative ones, and particularly to stimuli that we see as threatening and fear arousing. When we experience events that are dangerous, the amygdala stimulates the brain to remember the details of the situation so that we learn to avoid it in the future. The amygdala is activated when we look at facial expressions of other people experiencing fear or when we are exposed to members of racial outgroups (Morris, Frith, Perrett, & Rowland, 1996; Phelps et al., 2000).

Although the amygdala helps us perceive and respond to danger, and this may lead us to aggress, other parts of the brain serve to control and inhibit our aggressive tendencies. One mechanism that helps us control our negative emotions and aggression is a neural connection between the amygdala and regions of the prefrontal cortex (Gibson, 2002).

The prefrontal cortex is in effect a control center for aggression: when it is more highly activated, we are more able to control our aggressive impulses. Research has found that the cerebral cortex is less active in murderers and death row inmates, suggesting that violent crime may be caused at least in part by a failure or reduced ability to regulate emotions (Davidson, Jackson, & Kalin, 2000; Davidson, Putnam, & Larson, 2000).

Brain regions that influence aggression include the amygdala (area 1) and the prefrontal cortex (area 2). Individual differences in one or more of these regions or in the interconnections among them can increase the propensity for impulsive aggression.

Hormones Influence Aggression: Testosterone and Serotonin

Hormones are also important in creating aggression. Most important in this regard is the male sex hormone testosterone, which is associated with increased aggression in both animals and in humans. Research conducted on a variety of animals has found a strong correlation between levels of testosterone and aggression. This relationship seems to be weaker among humans than among animals, yet it is still significant (Dabbs, Hargrove, & Heusel, 1996).

In one study showing the relationship between testosterone and behavior, James Dabbs and his colleagues (Dabbs, Hargrove, & Heusel, 1996) measured the testosterone levels of 240 men who were members of 12 fraternities at two universities. They also obtained descriptions of the fraternities from university officials, fraternity officers, yearbook and chapter house photographs, and researcher field notes. The researchers correlated the testosterone levels and the descriptions of each of the fraternities. They found that the fraternities that had the highest average testosterone levels were also more wild and unruly, and in one case were known across campus for the crudeness of their behavior. The fraternities with the lowest average testosterone levels, on the other hand, were more well-behaved, friendly, academically successful, and socially responsible. Another study found that juvenile delinquents and prisoners who have high levels of testosterone also acted more violently (Banks & Dabbs, 1996). Testosterone affects aggression by influencing the development of various areas of the brain that control aggressive behaviors. The hormone also affects physical development such as muscle strength, body mass, and height that influence our ability to successfully aggress.

Although testosterone levels are much higher in men than in women, the relationship between testosterone and aggression is not limited to males. Studies have also shown a positive relationship between testosterone and aggression and related behaviors (such as competitiveness) in women (Cashdan, 2003). Although women have lower levels of testosterone overall, they are more influenced by smaller changes in these levels than are men.

It must be kept in mind that the observed relationships between testosterone levels and aggressive behavior that have been found in these studies cannot prove that testosterone causes aggression-the relationships are only correlational. In fact, the effect of aggression on testosterone is probably stronger than the effect of testosterone on aggression. Engaging in aggression causes temporary increases in testosterone. People who feel that they have been insulted show both more aggression as well as more testosterone (Cohen, Nisbett, Bosdle, & Schwarz, 1996), and the experience of stress is also associated with higher levels of testosterone and also with aggression. Even playing an aggressive game, such as tennis or chess, increases the testosterone levels of the winners and decreases the testosterone levels of the losers (Gladue, Boechler, & McCaul, 1989; Mazur, Booth, & Dabbs, 1992). Perhaps this is why the fans of the Montreal Canadiens, a professional ice hockey team, rioted after their team won an important game against the Pittsburgh Penguins in 2010.

Testosterone is not the only biological factor linked to human aggression. Recent research has found that serotonin is also important, as serotonin tends to inhibit aggression. Low levels of serotonin have been found to predict future aggression (Kruesi, Hibbs, Zahn, & Keysor, 1992; Virkkunen, de Jong, Bartko, & Linnoila, 1989). Violent criminals have lower levels of serotonin than do nonviolent criminals, and criminals convicted of impulsive violent crimes have lower serotonin levels than criminals convicted of premeditated crimes (Virkkunen, Nuutila, Goodwin, & Linnoila, 1987).

In one experiment assessing the influence of serotonin on aggression, Berman, McCloskey, Fanning, Schumacher, and Coccaro (2009) first chose two groups of participants, one of which indicated that they had frequently engaged in aggression (temper outbursts, physical fighting, verbal aggression, assaults, and aggression toward objects) in the past, and a second group that reported that they had not engaged in aggressive behaviors.

In a laboratory setting, participants from both groups were then randomly assigned to receive either a drug that raises serotonin levels or a placebo. Then the participants completed a competitive task with what they thought was another person in another room. (The opponent's responses were actually controlled by computer.) During the task, the person who won each trial could punish the loser of the trial by administering electric shocks to the finger. Over the course of the game, the "opponent" kept administering more intense shocks to the participants.

As you can see in Figure 9.6, the participants who had a history of aggression were significantly more likely to retaliate by administering severe shocks to their opponent than were the less aggressive participants. The aggressive participants who had been given serotonin, however, showed significantly reduced aggression levels during the game. Increased levels of serotonin appear to help people and animals inhibit impulsive responses to unpleasant events (Soubrié, 1986).

Participants who reported having engaged in a lot of aggressive behaviors (right panel) showed more aggressive responses in a competitive game than did those who reported being less aggressive (left panel). The aggression levels for the more aggressive participants increased over the course of the experiment for those who did not take a dosage of serotonin but aggression did not significantly increase for those who had taken serotonin. Data are from Berman et al. (2009).

Drinking Alcohol Increases Aggression

Perhaps unsurprisingly, research has found that the consumption of alcohol increases aggression. In fact, excessive alcohol consumption is involved in a majority of violent crimes, including rape and murder (Abbey, Ross, McDuffie, & McAuslan, 1996). The evidence is very clear, both from correlational research designs and from experiments in which participants are randomly assigned either to ingest or not ingest alcohol, that alcohol increases the likelihood that people will respond aggressively to provocations (Bushman, 1997; Graham, Osgood, Wells, & Stockwell, 2006; Ito, Miller, & Pollock, 1996). Even people who are not normally aggressive may react with aggression when they are intoxicated (Bushman & Cooper, 1990).

Alcohol increases aggression for a couple of reasons. First, alcohol disrupts executive functions, which are the cognitive abilities that help us plan, organize, reason, achieve goals, control emotions, and inhibit behavioral tendencies (Séguin & Zelazo, 2005). Executive functioning occurs in the prefrontal cortex, which is the area that allows us to control aggression. Alcohol therefore reduces the ability of the person who has consumed it to inhibit his or her aggression (Steele & Southwick, 1985). Acute alcohol consumption is more likely to facilitate aggression in people with low, rather than high, executive functioning abilities.

Second, when people are intoxicated, they become more self-focused and less aware of the social situation, a state that is known as alcohol myopia. As a result, they are less likely to notice the social constraints that normally prevent them from engaging aggressively and are less likely to use those social constraints to guide them. We might normally notice the presence of a police officer or other people around us, which would remind us that being aggressive is not appropriate, but when we are drunk we are less likely to be so aware. The narrowing of attention that occurs when we are intoxicated also prevents us from being aware of the negative outcomes of our aggression. When we are sober, we realize that being aggressive may produce retaliation as well as cause a host of other problems, but we are less likely to be aware of these potential consequences when we have been drinking (Bushman & Cooper, 1990).

Alcohol also influences aggression through expectations. If we expect that alcohol will make us more aggressive, then we tend to become more aggressive when we drink. The sight of a bottle of alcohol or an alcohol advertisement increases aggressive thoughts and hostile attributions about others (Bartholow & Heinz, 2006), and the belief that we have consumed alcohol increases aggression (Bègue et al., 2009).

Negative Emotions Cause Aggression

If you were to try to recall the times that you have been aggressive, you would probably report that many of them occurred when you were angry, in a bad mood, tired, in pain, sick, or frustrated. And you would be right-we are much more likely to aggress when we are experiencing negative emotions. When we are feeling ill, when we get a poor grade on an exam, or when our car doesn't start-in short, when we are angry and frustrated in general-we are likely to have many unpleasant thoughts and feelings, and these are likely to lead to violent behavior. Aggression is caused in large part by the negative emotions that we experience as a result of the aversive events that occur to us and by our negative thoughts that accompany them (Berkowitz & Heimer, 1989).

One kind of negative affect that increases arousal when we are experiencing it is frustration (Berkowitz, 1989; Dollard, Doob, Miller, Mowrer, & Sears, 1939). Frustration occurs when we feel that we are not obtaining the important goals that we have set for ourselves. We get frustrated when our computer crashes while we are writing an important paper, when we feel that our social relationships are not going well, or when our schoolwork is going poorly. How frustrated we feel is also determined in large part through social comparison. If we can make downward comparisons with important others, in which we see ourselves as doing as well or better than they are, then we are less likely to feel frustrated. But when we are forced to make upward comparisons with others, we may feel frustration. When we receive a poorer grade than our classmates received or when we are paid less than our coworkers, this can be frustrating to us.

Although frustration is an important cause of the negative affect that can lead to aggression, there are other sources as well. In fact, anything that leads to discomfort or negative emotions can increase aggression. Consider pain, for instance. Berkowitz (1993b) reported a study in which participants were made to feel pain by placing their hands in a bucket of ice-cold water, and it was found that this source of pain also increased subsequent aggression. As another example, working in extremely high temperatures is also known to increase aggression-when we are hot, we are more aggressive. Griffit and Veitch (1971) had students complete questionnaires either in rooms in which the heat was at a normal temperature or in rooms in which the temperature was over 32 degrees Celsius (90 degrees Fahrenheit). The students in the latter condition expressed significantly more hostility.

Hotter temperatures are associated with higher levels of aggression (Figure 9.7) and violence (Anderson, Anderson, Dorr, DeNeve, & Flanagan, 2000). Hotter regions generally have higher violent crime rates than cooler regions, and violent crime is greater on hot days than it is on cooler days, and during hotter years than during cooler years (Bushman, Wang, & Anderson, 2005). Even the number of baseball batters hit by pitches is higher when the temperature at the game is higher (Reifman, Larrick, & Fein, 1991). Researchers who study the relationship between heat and aggression have proposed that global warming is likely to produce even more violence (Anderson & Delisi, 2011).

Research Focus

The Effects of Provocation and Fear of Death on Aggression

McGregor et al. (1998) demonstrated that people who have been provoked by others may be particularly aggressive if they are also experiencing negative emotions about the fear of their own death. The participants in the study had been selected, on the basis of prior reporting, to have either politically liberal or politically conservative views. When they arrived at the lab they were asked to write a short paragraph describing their opinion of national politics. In addition, half of the participants (the mortality salience condition) were asked to "briefly describe the emotions that the thought of your own death arouses in you" and to "Jot down as specifically as you can, what you think will happen to you as you physically die, and once you are physically dead." Participants in the exam control condition also thought about a negative event, but not one associated with a fear of death. They were instructed to "Please briefly describe the emotions that the thought of your next important exam arouses in you'' and to "Jot down as specifically as you can, what you think will happen to you as you physically take your next exam, and once you are physically taking your next exam."

Then the participants read an essay that had supposedly just been written by another person in the study. (The other person did not exist, but the participants didn't know this until the end of the experiment.) The essay that the participants read had been prepared by the experimenters to condemn politically liberal views or to condemn politically conservative views. Thus one-half of the participants were provoked by the other person by reading a statement that strongly conflicted with their own political beliefs, whereas the other half read an essay that supported their beliefs (liberal or conservative).

At this point, the participants moved on to what they thought was a completely separate study in which they were to be tasting and giving their impression of some foods. Furthermore, they were told that it was necessary for the participants in the research study to administer the food samples to each other. The participants then found out that the food they were going to be sampling was spicy hot sauce and that they were going to be administering the sauce to the same person whose essay they had just read! In addition, the participants read some information about the other person that indicated that the other person very much disliked eating spicy food. Participants were given a taste of the hot sauce (which was very hot) and then instructed to place a quantity of it into a cup for the other person to sample. Furthermore, they were told that the other person had to eat all the sauce.

As you can see in Figure 9.8, "Mortality Salience and Aggression," this research provides another example of how negative feelings can lead us to be aggressive after we have been provoked. The threatening essay had little effect on the participants in the exam control condition. On the other hand, the participants who were both provoked by the other person and who had also been reminded of their own death administered significantly more aggression than did the participants in the other three conditions.

A threat to one's worldview increased aggression but only for participants who had been thinking about their own death. Data are from McGregor et al. (1998).

Just as negative feelings can increase aggression, positive affect can reduce it. In one study (Baron & Ball, 1974), participants were first provoked by an experimental confederate. Then the participants were, according to random assignment, shown either funny cartoons or neutral pictures. When the participants were given an opportunity to retaliate by giving shocks as part of an experiment on learning, those who had seen the positive cartoons gave fewer shocks than those who had seen the neutral pictures.

It seems that feeling good about ourselves, or feeling good about others, is incompatible with anger and aggression. You can see that this is in essence the flip side of the results we discussed in Chapter 8, "Helping and Altruism," regarding altruism: just as feeling bad leads us to aggress, feeling good makes us more likely to help and less likely to hurt others. This makes perfect sense, of course, since emotions are signals regarding the threat level around us. When we feel good, we feel safe and do not think that we need to aggress.

Of course, negative emotions do not always lead to aggression toward the source of our frustration. If we receive a bad grade from our teacher or a ticket from a police officer, it is not likely that we will directly aggress against him or her. Rather, we may displace our aggression onto others, and particularly toward others who seem similar to the source of our frustration (Miller, Pedersen, Earleywine, & Pollock, 2003). Displaced aggression occurs when negative emotions caused by one person trigger aggression toward a different person. A recent meta-analysis has found clear evidence that people who are provoked but are unable to retaliate against the person who provoked them are more aggressive toward an innocent other person, and particularly toward people who are similar in appearance to the true source of the provocation, in comparison to those who were not previously provoked (Marcus-Newhall, Pedersen, Carlson, & Miller, 2000).

It is clear that negative affect increases aggression. And you will recall that emotions that are accompanied by high arousal are more intense than those that have only low levels of arousal. Thus it would be expected that aggression is more likely to occur when we are more highly aroused, and indeed this is the case. For instance, in his important research on arousal, Dolf Zillmann found that many types of stimuli that create arousal, including riding on a bicycle, listening to an erotic story, and experiencing loud noises, tend to increase both arousal as well as aggression (Zillman, Hoyt, & Day, 1974; Zillman, Katcher, & Milavsky, 1972). Arousal probably has its effects on aggression in part through the misattribution of emotion. If we are experiencing arousal that was actually caused by a loud noise or by any other cause, we might misattribute that arousal as anger toward someone who has recently frustrated or provoked us.

Can We Reduce Negative Emotions by Engaging in Aggressive Behavior?

We have seen that when we are experiencing strong negative emotions accompanied by arousal, such as when we are frustrated, angry, or uncomfortable, or anxious about our own death, we may be more likely to aggress. However, if we are aware that we are feeling these negative emotions, we might try to find a solution to prevent ourselves from lashing out at others. Perhaps, we might think, if we can release our negative emotions in a relatively harmless way, then the probability that we will aggress might decrease. Maybe you have tried this method. Have you ever tried to yell really loud, hit a pillow, or kick something when you are angry, with the hopes that doing so will release your aggressive tendencies?

The idea that engaging in less harmful aggressive actions will reduce the tendency to aggress later in a more harmful way, known as catharsis, is an old one. It was mentioned as a way of decreasing violence by the Greek philosopher Aristotle and was an important part of the theories of Sigmund Freud. Many others believe in catharsis too. Russell, Arms, and Bibby (1995) reported that more than two-thirds of the people they surveyed believed in catharsis, agreeing with statements that suggested that participating in and observing aggressive sports and other aggressive activities is a good way to get rid of one's aggressive urges. People who believe in the value of catharsis use it because they think that doing so is going to make them feel better (Bushman, Baumeister, & Phillips, 2001). The belief in catharsis leads people to engage in popular techniques such as venting and cathartic therapies or even to play violent video games (Whitaker, Melzer, Steffgen, & Bushman, 2013), even though numerous studies have shown that these approaches are not effective.

It is true that reducing negative affect and arousal can reduce the likelihood of aggression. For instance, if we are able to distract ourselves from our negative emotions or our frustration by doing something else, rather than ruminating on it, we can feel better and will be less likely to aggress. However, as far as social psychologists have been able to determine, attempting to remove negative emotions by engaging in or observing aggressive behaviors (that is, the idea of catharsis) simply does not work.

In one relevant study, Bushman, Baumeister, and Stack (1999) first had their participants write an article about their opinions about a social topic such as abortion. Then they convinced them that another participant had read the article and provided very negative feedback about it. The other person said such things as, "This is one of the worst essays I have read!" Then the participants read a message suggesting that catharsis really did work. (It claimed that engaging in aggressive action is a good way to relax and reduce anger.) At this point, half of the participants were allowed to engage in a cathartic behavior-they were given boxing gloves, some instructions about boxing, and then got a chance to hit a punching bag for two minutes.

Then all the participants got a chance to engage in aggression with the same person who had angered them earlier. The participant and the partner played a game in which the losing person on each trial received a blast of noise. At the beginning of each trial, each participant was permitted to set the intensity of the noise that the other person would receive if he or she lost the trial, as well as the duration of the loser's suffering, because the duration of the noise depended on how long the winner pressed the button.

Contrary to the catharsis hypothesis, the students who punched the punching bag did not release and reduce their aggression as the message they had read suggested would happen. Rather, these students actually set a higher noise level and delivered longer bursts of noise than did the participants who did not get a chance to hit the punching bag. It seems that if we hit a punching bag, punch a pillow, or scream as loud as we can, with the idea of releasing our frustration, the opposite occurs-rather than decreasing aggression, these behaviors in fact increase it (Bushman et al., 1999). Participating in aggression simply makes us more, not less, aggressive.

One prediction that could be derived from the catharsis idea is that countries that are currently fighting wars would show less domestic aggression than those that are not. After all, the citizens in these countries read about the war in the newspapers and see images of it on TV on a regular basis-wouldn't that reduce their needs and desires to aggress in other ways? Again, the answer is no. Rather than decreasing, aggression increases when the country that one lives in is currently or recently fighting a war, perhaps in part because war hardens group alliances (Bauer, Cassar, Chytilová & Heinrich, 2014). In an archival study, Archer and Gartner (1976) found that countries that were in wars experienced significant postwar increases in their rates of homicide. These increases were large in magnitude, occurred after both large wars and smaller wars, with several types of homicide rate indicators, in victorious as well as defeated nations, in nations with both improved and worsened postwar economies, among both men and women offenders, and among offenders of several age groups. Homicide rate increases occurred with particular consistency among nations with large numbers of combat deaths.

The increases in aggression that follow from engaging in aggressive behavior are not unexpected-and they occur for a variety of reasons. For one, engaging in a behavior that relates to violence, such as punching a pillow, increases our arousal. Furthermore, if we enjoy engaging in the aggressive behavior, we may be rewarded, making us more likely to engage in it again. And aggression reminds us of the possibility of being aggressive in response to our frustrations. In sum, relying on catharsis by engaging in or viewing aggression is dangerous behavior-it is more likely to increase the flames of aggression than to put them out. It is better to simply let the frustration dissipate over time or perhaps to engage in other nonviolent but distracting activities.

Key Takeaways

The ability to aggress is part of the evolutionary adaptation of humans. But aggression is not the only, nor always the best, approach to dealing with conflict.

The amygdala plays an important role in monitoring fearful situations and creating aggressive responses to them. The prefrontal cortex serves as a regulator to our aggressive impulses.

The male sex hormone testosterone is closely associated with aggression in both men and women. The neurotransmitter serotonin helps us inhibit aggression.

Negative emotions, including fear, anger, pain, and frustration, particularly when accompanied by high arousal, may create aggression.

Contrary to the idea of catharsis, social psychological research has found that engaging in aggression does not reduce further aggression.

Exercises and Critical Thinking

1. Recall a time when you experienced frustration. Did you react with aggression? If so, what type of aggression was it?

2. Consider a time when you or someone you know engaged in an aggressive act with the goal of reducing further aggression (catharsis). Was the attempt successful?

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Principles of Social Psychology - 1st International Edition

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Explain how aggression might be evolutionarily adaptive. Describe how different parts of the brain influence aggression. Summarize the effects of testosterone and serotonin on aggression. When we see so much violence around us every day, we might conclude that people have an innate tendency, or even an instinct, to be aggressive.

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Learning Objectives

1. Review the situational variables that increase and decrease aggression.

2. Explain the different effects of reward, punishment, and modeling on aggression.

3. Review the influences of viewing violent behavior on aggression and explain why these effects might occur.

Although emotions and biology are critical, they are not the only determinants of our aggression. Of particular importance to social psychologists is the role of the social situation.

Social Learning and Modeling: Is Aggression Learned?

As would be predicted by principles of social reinforcement, if we are rewarded for being aggressive, we'll likely aggress again, but if we are punished for our violence, we may subsequently curb our aggression. The child who gets a toy by hitting another child and taking it is likely to continue being aggressive in the future, particularly if he or she is not punished for the action. Children who are more aggressive are also often seen as more competent, in part because they can use their aggression to get their way (Hawley, 2007). Björkqvist et al. (2001) found that girls who use nonphysical aggression reported being less lonely and were more likely to have higher status than did nonaggressive girls. In another study, aggressive boys were more likely to be accepted by their peers than were nonaggressive boys (Salmivalli, Kaukiainen, & Lagerspetz, 2000). Aggression seems to be paying off for these students.

Some aggression is learned through modeling the violence that we see all around us every day (Bandura & Walters, 1959). In his important research on aggression, Albert Bandura demonstrated that children learned new aggressive behaviors by observing aggressive models (Bandura, 1973). Bandura argued that we don't just imitate the specific behaviors that we see, but that viewing aggression changes our schemas and our attitudes about aggression. Watching a parent hitting another person may not only increase a child's likelihood of hitting but may also increase his or her beliefs that "hitting is OK" and that "one way to solve problems is by hitting." Modeling teaches new ideas about aggression and can help explain why exposure to violence increases aggressive behavior in the long run (Huesmann & Kirwil, 2007).

Modeling is particularly problematic for children who grow up in violent families. These children are not only the victims of aggression, but they also see violence being inflicted on their parents and siblings. Because children learn how to be parents in large part by modeling the actions of their parents, it is no surprise that there is a strong correlation between family violence in childhood and violence as an adult. Children who witness their parents being violent or who are themselves abused are more likely as adults to inflict abuse on their partners and children (Heyman & Slep, 2002). In turn, their own children are also more likely to interact violently with each other and to aggress against their parents (Patterson, Dishion, & Bank, 1984).

Although rewards clearly increase aggression, perhaps punishment decreases it? Judicial systems are based in large part on punishing people for being aggressive, with fines, jail terms, and even the death penalty being used as punishments. There is, however, a problem with using punishment to reduce aggression, particularly when the punishment is itself aggressive. The problem is that the punishment may be modeled, which can increase the aggressive behaviors that we are trying to stop. In a meta-analysis, Gershoff (2002) found that although children who were spanked by their parents were more likely to immediately comply with the parents' demands, they were also more aggressive, showed less ability to control aggression, and had poorer mental health in the long term. The problem seems to be that children who are punished for bad behavior may be more likely to change their behavior only for external reasons, rather than internalizing the norms of being good for its own sake.

Punishment is most effective when it is intense, prompt (before the person can derive much pleasure from the aggression), applied consistently and with certainty, perceived as justified, and replaced by a more desirable alternative behavior (Berkowitz, 1993). But even if punishment occurs under these ideal conditions, it may only suppress aggressive behavior temporarily (Baron & Richardson, 1994; Berkowitz, 1993).

One example of the use of violence to attempt to stop violence is capital punishment-the use of the death penalty. Although banned in many countries, capital punishment is used in countries such as the United States, Egypt, India, Saudi Arabia, Singapore, and Vietnam. Although many people believe that capital punishment deters crime, there is little evidence that it actually does (Archer, Gartner, & Beittel, 1983). For one, the time period between the crime and the punishment is typically many years long, which makes it less effective as a deterrent. Second, many of the crimes that are punished by the death penalty involve emotional aggression and are not premeditated. They occur during arguments or while the perpetrator is under the influence of alcohol or recreational drugs. In these cases, even if the perpetrator has knowledge of the death penalty, this knowledge is not likely to have much effect on reducing crime. And capital punishment also means that many innocent people are wrongly executed for crimes they did not commit.

Violence Creates More Violence: Television, Video Games, and Handguns

Worldwide, the average child watches over three hours of television every day, and these programs contain both physical and nonphysical aggression at the rate of about three violent acts per minute (Archer & Coyne, 2005; Groebel, 1999; Shanahan, Hermans, & Hyman, 2003). Furthermore, the amount, intensity, and graphic nature of the violence that children view continues to escalate every year. According to a study of programming from 1993 to 2001 on six major Canadian television networks, depictions of physical violence increased by 378% over this period, to the tune of about 40 acts of violence per hour (Paquette, Gosselin, & DeGuise, 1997). These programs are punctuated with television advertisements, approximately 13% of which also contain violent content (Jones & Cunningham, 2008). At the same time, children are also exposed to violence in movies and video games, as well as in popular music and music videos that include violent lyrics and imagery.

Given your knowledge about the importance of the social situation, it might not surprise you to hear that these situational exposures to violence have an effect on aggressive behavior, and in fact they do. The evidence is impressive and clear: the more media violence people, including children, view, the more aggressive they are likely to be (Anderson et al., 2003; Cantor et al., 2001). The relation between viewing TV violence and aggressive behavior is about as strong as the relation between smoking and cancer or between studying and academic grades (Bushman & Huesmann, 2010). If you watch a lot of violence, you are likely to become aggressive!

The evidence is so clear because it has come through the accumulation of many studies conducted over many years, using a variety of research designs. These studies have included laboratory and field experiments, as well as both cross-sectional and longitudinal correlational studies, and have included people from many different cultures. In the correlational studies, many potential common-causing variables, such as intelligence, family background, socioeconomic status, and personality, have been controlled for. The potential for reverse causation has been eliminated through studies that have shown that viewing violence at a young age tends to predict aggressive behavior when the child is older, more than the other way around. Furthermore, laboratory studies in which people have been randomly assigned to view either violent or nonviolent material have shown the same results (Paik & Comstock, 1994; Zillman & Weaver, 1999). In one recent study, Coyne, Archer, and Eslea (2004) found that adolescents who viewed either physical or nonphysical aggression were subsequently more likely to behave in an aggressive manner than those who viewed no aggression.

Research Focus

The Effects of Violent Video Games on Aggression

It is clear that watching TV violence can increase aggression, but what about violent video games? These games are more popular than ever and also more graphically violent. Children spend countless hours playing video games, many of which involve engaging in extremely violent behaviors. The games often require the player to take the role of a violent person, to identify with the character, to select victims, and, of course, to kill people. These behaviors are rewarded by winning points and moving on to higher levels and are repeated over and over.

Again, the answer is clear-playing violent video games leads to aggression. A meta-analysis (Anderson & Bushman, 2001) that reviewed 35 research studies that had tested the effects of playing violent video games on aggression. The studies included both experimental and correlational studies, with both male and female participants in both laboratory and field settings. They found that exposure to violent video games is significantly linked to increases in aggressive thoughts, aggressive feelings, psychological arousal (including blood pressure and heart rate), as well as aggressive behavior. Furthermore, playing more video games was found to relate to less altruistic behavior.

Bushman and Anderson (2002) directly assessed the effects of viewing violent video games on aggressive thoughts and behavior. In one of their studies, participants were randomly assigned to play either a violent or a nonviolent video game for 20 minutes. Each participant played one of four violent video games (Carmageddon, Duke Nukem, Mortal Kombat, or Future Cop) or one of four nonviolent video games (Glider Pro, 3D Pinball, Austin Powers, or Tetra Madness).

Participants then read a story-for instance, this one about Todd-and were asked to list 20 thoughts, feelings, and actions about how they would respond if they were Todd:

Todd was on his way home from work one evening when he had to brake quickly for a yellow light. The person in the car behind him must have thought Todd was going to run the light because he crashed into the back of Todd's car, causing a lot of damage to both vehicles. Fortunately, there were no injuries. Todd got out of his car and surveyed the damage. He then walked over to the other car.

As you can see in Figure 9.9, the students who had played one of the violent video games responded much more aggressively to the stories than did those who played the nonviolent games. In fact, their responses were often extremely aggressive. They said things like "Call the guy an idiot," "Kick the other driver's car," "This guy's dead meat!" and "What a dumbass!" Other studies have found similar results (Konijn, Nije Bijvank, & Bushman, 2007), and longitudinal studies in the United States and in Japan have shown that playing violent video games predicts aggressive behaviors and thoughts several months later, even after controlling for initial level of aggression (Anderson, Gentile, & Buckley, 2007; Anderson et al., 2008).

Why Does Viewing Violence Lead to Aggression?

There is strong evidence that viewing aggression on TV, playing violent video games, and exposure to violence in general tends to increase the likelihood of aggression. But why might viewing violence increase aggression?

Perhaps the strongest possibility is also the simplest-that viewing violence increases the cognitive accessibility of violence. When we see violence, violence is then activated in memory and becomes ready to guide our subsequent thinking and behavior in more aggressive ways. One way of understanding this process is shown in Figure 9.10, "Priming Aggression." According to this model, the activation from the viewed violence spreads automatically in memory from the perceived violent acts to other aggressive ideas and in the end increases the likelihood of engaging in violence (Anderson, Benjamin, & Bartholow, 1998).

Worldwide, about 1,000 people are killed every day as a result of gun violence. Of these, about 560 are the result of criminal homicides, 250 are direct war deaths, 140 are suicides, and 50 are accidents (International Action Network on Small Arms, 2006). Although school and workplace shootings have been of particular concern in recent years, even people who keep guns in their home for protection are likely to be killed by that gun-particularly at the hands of a family member-and are also likely to kill themselves with it (Cummings, Koepsell, Grossman, Savarino, & Thompson, 1997; Wintemute, Parham, Beaumont, Wright, & Drake, 1999).

Although it is true that it is people and not the guns themselves that do the killing, principles of social psychology make it clear why possessing guns is so dangerous. Guns provide cues about violence, which makes it more likely that people will respond to provocation with aggression. In any particular situation of conflict or confrontation, we have several choices. We might try to escape the situation, we might confront the person in a nonviolent way, or we might choose to use violence. The presence of guns reminds us that we may respond with violence. When guns are around, violence is highly cognitively accessible, and this accessibility increases the likelihood of responding to provocation with violence.

Research has shown that the presence of guns provides a highly salient cue, which reminds us that aggression is a possible response to threat. Anderson, Benjamin, and Bartholow (1998) found that just having participants think about guns primed thoughts about aggression. But the link does not end there. In addition to priming aggressive thoughts and feelings, viewing handguns also increases violent behavior, particularly when we are provoked (Carlson, Marcus-Newhall, & Miller, 1990).

In one famous study (Berkowitz & Lepage, 1967), male university students were given either one or seven painful electrical shocks, supposedly from another student, and then were given an opportunity to shock this person in return. In some cases, a 12-gauge shotgun and a .38-caliber revolver were lying on the table near the shock key, whereas in other conditions, two badminton racquets were near the key. The researchers found, first, that the students who had been shocked more times returned significantly more shocks to the partner than did those who had been shocked only once. But what about the presence of the guns? The researchers found that the guns did not significantly increase aggression for the participants who had received only one shock, but it did increase aggression for those who had received seven shocks. The presence of the guns seems to have elicited more aggressive responses from those who had been most provoked by the shocks. Given what you know about the importance of situational effects on priming, these results may not surprise you.

Another way that viewing violence increases aggression is through modeling. Children (and even adults) may simply imitate the violence they observe. Indeed, there is substantial evidence that people do copy the aggression that they read about or see in the media. For instance, when Belgian teenager Alisson Cambier spurned the romantic advances of her 24-year-old neighbour Thierry Jaradin, he excused himself only to return to the room wearing a ghostface costume and carrying two knives, which he used to stab her 30 times. He later admitted that the murder was premeditated and inspired by the horror film Scream. Research also has found strong evidence for copycat suicides. The rate of suicide in the general population increases significantly in the months after famous people, for instance Marilyn Monroe or Kurt Cobain, commit suicide (Phillips & Carstensen, 1986). In short, viewing violence teaches us how and when we should be aggressive.

Another outcome of viewing large amounts of violent material is desensitization, the tendency to become used to, and thus less influenced by, a stimulus. When we first see violence, we are likely to be shocked, aroused, and even repulsed by it. However, as we see more and more violence over time, we become habituated to it, such that subsequent exposures produce fewer and fewer negative emotional responses. In the end, we may begin to see violence as a normal part of everyday life and become accepting of it.

In sum, continually viewing violence substantially changes how we think about and how our brains respond to the events that occur to us (Bartholow, Bushman, & Sestir, 2006). Frequent exposure to violence primes aggression and makes aggressive behavior more likely (Molitor & Hirsch, 1994). And viewing aggression frequently makes that aggression seem more normal and less negative. If we create for ourselves a world that contains a lot of violence, we become more distrustful and more likely to behave aggressively in response to conflict (Nabi & Sullivan, 2001).

Key Takeaways

Aggression can be explained in part by the general principles of learning, including reinforcement, punishment, and modeling.

Reinforcement is more effective than punishment in reducing aggression.

Viewing violence in TV shows, movies, and video games tends to create aggression in the viewer.

Exposure to violence increases aggression through reinforcement, through modeling, by priming cognitions related to aggression, and through desensitization.

Exercises and Critical Thinking

1. Describe a time when you were reinforced or punished for your aggressive behavior or when someone you knew was. Was the attempt to reduce aggression successful?

2. Watch some children's television programming for one hour and make a note of the number and types of incidences of aggression depicted.

3. Do you or people you know watch a lot of TV violence or play violent video games? How do you think this exposure is influencing you or them? Do you think you are less susceptible to violent media than other people?

References

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Anderson, C. A., Benjamin, A. J., Jr., & Bartholow, B. D. (1998). Does the gun pull the trigger? Automatic priming effects of weapon pictures and weapon names. Psychological Science, 9(4), 308-314.

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Berkowitz, L. (1993). Aggression: Its causes, consequences and control. New York, NY: McGraw-Hill.

Berkowitz, L., & Lepage, A. (1967). Weapons as aggression-eliciting stimuli. Journal of Personality and Social Psychology, 7(2, Pt.1), 202-207.

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Bushman, B. J., & Anderson, C. A. (2002). Violent video games and hostile expectations: A test of the general aggression model. Personality and Social Psychology Bulletin, 28(12), 1679-1686.

Bushman, B. J., & Huesmann, L. R. (2010). Aggression. In S. T. Fiske, D. T. Gilbert, & G. Lindzey (Eds.), Handbook of social psychology (Vol. 2, 5th ed., pp. 833-863). Hoboken, NJ: John Wiley & Sons.

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Coyne, S. M., Archer, J., & Eslea, M. (2004). Cruel intentions on television and in real life: Can viewing indirect aggression increase viewers' subsequent indirect aggression? Journal of Experimental Child Psychology, 88(3), 234-253.

Cummings, P., Koepsell, T. D., Grossman, D. C., Savarino, J., & Thompson, R. S. (1997). Association between the purchase of a handgun and homicide or suicide. American Journal of Public Health, 87(6), 974-978.

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Huesmann, L. R., & Kirwil, L. (2007). Why observing violence increases the risk of violent behavior by the observer. In D. J. Flannery, A. T. Vazsonyi, & I. D. Waldman (Eds.), The Cambridge handbook of violent behavior and aggression (pp. 545-570). New York, NY: Cambridge University Press.

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# data[].attributes.attachment_link.title
The Violence around Us: How the Social Situation Influences Aggression

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Review the situational variables that increase and decrease aggression. Explain the different effects of reward, punishment, and modeling on aggression. Review the influences of viewing violent behavior on aggression and explain why these effects might occur. Although emotions and biology are critical, they are not the only determinants of our aggression.

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http://cureviolence.org/understand-violence/

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We Can Cure Violence

Years ago we did not understand violence, but today science has actually figured out a lot of what causes violence and can help to show us how to prevent it.

Scientific Discovery of Epidemic Diseases

Hundreds of years ago, people were dying by the thousand, but nobody knew why. We tried to come up with reasons: that the sick people were "bad" people, morally responsible for their plight; the conditions and poverty in the ghettos caused it; certain races of people were responsible for it.

These explanations were all wrong. People were dying because of a tiny little bug - plague, cholera, small pox, and others. At the time, this idea - that an invisible bug was killing people - would have been seen as preposterous. Scientific discovery allowed us to understand this as the true cause. And with this understanding came an understanding of how to treat it, even when cures do not exist. Today, epidemic diseases are largely a thing of the past. Violence can be a thing of the past too.

Violence as a Health Issue

Violence is a health issue because it negatively affects the health of people - both the obvious physical injuries of the victims as well as those who witness violence and consequently suffer from mental trauma. Counterintuitively, this mental trauma from exposure has been scientifically shown to increase a person's risk of adopting violent behavior themselves, meaning that violent behavior transmits and spreads based on exposure - just like an epidemic disease. Using health approaches to treat violence like an epidemic disease can effectively reduce violence.
Learn more about violence as a health issue.
Science of Violent Behavior

What causes people to behave violently? If we want to seriously address violence, we must answer this question. To start, violence is driven by the brain, which regulates and controls all behaviors. Many discoveries have been made about the invisible workings of the brain in the fields of social psychology, neurology, and epidemiology that have shed some light on how behaviors are formed.
Learn more about the science of violent behavior.
Changing Behavior

Violence is a learned behavior that can be unlearned. To stop violence, we need to change individual, group and community behaviors. We have been able to do this in our program sites by using the latest understandings and data to identify and effectively treat those who are behaving violently using credible messengers.
Learn more about changing behavior.

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Years ago we did not understand violence, but today science has actually figured out a lot of what causes violence and can help to show us how to prevent it. Hundreds of years ago, people were dying by the thousand, but nobody knew why.

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Raising Children to Resist Violence: What You Can Do

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Children learn aggressive behavior early in life. Several strategies can help parents and others teach kids to manage their emotions without using violence.

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How Violence in Television Shows Desensitizes Children | Livestrong.com

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While researchers often disagree about the relationship between watching violent television programs and aggressive behavior in children, there are enough indicators of a correlation for you to consider limiting your children's TV viewing of violent programming, according to the Media Awareness Network.

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Credit: Eskymaks | Shutterstock.com

Although it's often assumed that males who feel they are "manly" men are more likely to engage in violence than those who are less concerned about their masculinity, men who feel they don't meet perceived masculine gender norms and are stressed about it may be equally prone to violent acts, a new study finds.

Researchers found that men who feel they fall short of society's "macho man" standards and are unhappy about it may be more likely to commit violent assaults using weapons than men who are comfortable with their masculinity.

In general, men are more likely than women to suffer from poor health and injury, likely because they tend to gravitate toward riskier behavior, the researchers said. Men typically are more prone than women to engage in substance abuse, binge drinking, reckless driving, violent acts and to carry weapons than women. [ 5 Myths About the Male Body]

The researchers tested their theory that men's dangerous, risk-taking behavior stems from insecurity with their masculinity; when a man perceives himself to be less masculine than traditional societal standards and feels that others see him the same way, he is said to have " gender role discrepancy," and the tension he feels is known as "discrepancy stress."

In 2012, the scientists conducted an online survey that probed how the male participants perceived masculinity standards and how their own self-image fit in with this perception. The 600 male participants, who were paid $2, were asked whether they felt as masculine as the average guy or if they wished to be more macho. The survey also included information about the individual's substance use and violent behavior.

The researchers found that the men with high discrepancy stress were more likely to be violent than the men who were not as concerned about their masculinity. The two groups, however, were not likely to differ significantly in their alcohol and drug use, the scientists said.

The researchers did not provide participants with a set standard for masculinity. In some cases, survey respondents interpreted "being macho" as being aggressive and hypersexual, while others saw it as being a good husband and father, said Dennis Reidy, the study's lead author and a behavioral scientist at the Centers for Disease Control and Prevention.

The ages of the American survey participants ranged between 18 and 50 years, the researchers said, and the distribution of the respondents' ethnicities and incomes was consistent with the general population in the United States - 72 percent Caucasian, 13 percent Asian, 7 percent African-American and 7 percent Hispanic.

The participants had a median annual income of $37,000, although the most frequently reported income was $55,000, and salaries ranged from $5,000 a year to more than $100,000. The average age skewed slightly younger, at 27.2 years. The participants were also slightly more educated than the general American public, with the average participant having had some college education.

Men characterized as having high gender role discrepancy and high discrepancy stress reported that they partook in assaults causing injury 348 percent more than men with low discrepancy stress, the researchers said.

"These findings suggest prevention of discrepancy stress may likewise prevent acts of violence with the greatest consequences and costs to the victim, offender and society," the researchers wrote in the study.

Although there was a strong association between perceptions about masculinity and propensity to violence, there was no association between discrepancy stress and the average daily use of alcoholand drugs, the researchers found. However, men who felt less masculine and were not worried about it were the least likely to report violence or driving while intoxicated.

The researchers suggest that efforts to reduce men's risky behavior should focus on how men internalize society's masculinity standards, and how these standards can cause stress in boys and men.

The findings also show that different kinds of men - those who feel they are very masculine and those who don't see themselves as masculine enough and are upset about it, for instance - may need different types of intervention strategies, Reidy told Live Science.

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Elizabeth Goldbaum, Live Science Contributor

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Insecure Men May Be More Prone to Violence

# data[].attributes.attachment_link.description
Although it's often assumed that males who feel they are "manly" men are more likely to engage in violence than those who are less concerned about their masculinity, men who feel they don't meet perceived masculine gender norms and are stressed about it may be equally prone to violent acts, a new study finds.

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Post Traumatic Stress Disorder ( PTSD) has been invoked to help explain many aspects of human behavior, including violence. The April 2 shooting at Fort Hood in Texas that left three dead and sixteen injured is but a recent example. Although, according to reports, the alleged killer never was involved in direct combat, "PTSD" was immediately cited as a possible contributory factor to the assailant's behavior.

According to the DSMV (the most recent edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders), the criteria for diagnosing the disorder include the following, none of which specifically mentions violent behavior:
*Exposure to actual or threatened death, serious injury, or sexual violence;
*Intrusive symptoms such as distressing dreams or memories, dissociative reactions (e.g., flashbacks);
*Intense or prolonged psychological distress at exposure to internal or external cues that resemble an aspect of the traumatic event;
*Negative alterations in cognitions and mood associated with the traumatic event;
*Duration of the disturbance is more than a month;
*The disturbance causes clinically significant distress or impairment in social occupational or other important areas of functioning.

There are innumerable sources of trauma and what may be one person's trauma may be another person's challenge. An event that leaves one person angry and scarred for life may result in the inner strengthening of another individual who proves to be resilient and calm. When endeavoring to understand troubling behavior, especially criminal conduct, one may find a convenient explanation if the individual has endured trauma at some point in his life. We often read that a person commits child abuse because of the trauma he experienced by being abused when he was a child. Yet most children who are abused do not abuse others. A person is thought to have become violent because he was a victim of violence. Yet someone else experiencing similar trauma does not engage in violent behavior.

Most military personnel who experience horrendous traumatic events during combat do not come home and kill civilians. In fact, their more likely reaction is to withdraw, become anxious, and become fearful of their surroundings. They are far more likely to become avoidant than lash out at others.

A woman whom I know was traumatized when a robber stuck a gun to her head while she was working at a bank. She suffered PTSD symptoms, including nightmares and flashbacks. Afraid to even leave her house, she became determined she would not assume the identity of a victim and remain incapacitated. Resolving that she would work again, she forced herself to take small steps in order to recover, first walking a few blocks from her apartment, then riding a bus, then going shopping, finally becoming confident enough to take a job at a department store. Violence was not a part of her personality either before or after she was subjected to a traumatic event.

Instead of focusing on PTSD as an all-encompassing, and far too facile an explanation of human behavior, it is essential to understand in detail the personality makeup of the person BEFORE the trauma occurred. That is more likely to explain human behavior than simply assuming that a trauma transformed the victim into a person who is totally different from the way he was before he experienced the trauma. Such an analysis can facilitate more effective treatment of PTSD and other psychological problems.

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PTSD: An Explanation for Violent Behavior?

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Post Traumatic Stress Disorder ( PTSD) has been invoked to help explain many aspects of human behavior, including violence. The April 2 shooting at Fort Hood in Texas that left three dead and sixteen injured is but a recent example.

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Jackson Katz: Violence against women—it's a men's issue

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At TEDWomen, Tony Porter makes a call to men everywhere: Don't "act like a man." Telling powerful stories from his own life, he shows how this mentality, drummed into so many men and boys, can lead men to disrespect, mistreat and abuse women and each other. His solution: Break free of the "man box."