PSYC 2120 Lecture Notes - Chemical Substance, Amygdala

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PSYC 2120 Chapter 11: Aggression
What is aggression?
- Aggression is an intentional behaviour aimed at causing either physical or psychological
pain
- Hostile aggression is an act of aggression stemming from feelings of anger and aimed at
inflicting pain
- Instrumental aggression, aggression as a means to some goal other than causing pain.
For example, in a professional football game, a defensive lineman will usually do
whatever it takes to thwart his opponent (the blocker) and tackle the ball carrier
- Sigmund Freud, who theorized that human beings are born with an instinct toward life,
which he called eros, and an equally powerful death instinct, thanatos, which leads to
aggressive actions
- Freud believed that aggressive energy must come out somehow, lest it continue to build
up and produce illness
- Also according to Freud, society performs an essential function in regulating this instinct
and in helping people to sublimate it, that is, to turn the destructive energy into
acceptable or useful behaviour
- Because aggressiveness has had survival value, most contemporary social psychologists
accept the proposition that it is part of our evolutionary heritage
- At the same time we know that human beings have developed exquisite mechanisms for
controlling their aggressive impulses, and that human behaviour is flexible and adaptable
to changes in the environment.
- Whether aggression is actually expressed depends on a complex interplay between our
biological propensities and the social situation in which we find ourselves
Neural and chemical influences on aggression
- Aggressive behaviour in human beings, as well as in lower animals, is associated with an
area in the core of the brain called the amygdala
- When the amygdala is stimulated, docile organisms become violent; similarly, when
neural activity in that area is blocked, violent organisms become docile. However, the
impact of neural mechanisms can be modified by social factors, even in subhumans. For
example, if a male monkey is in the presence of other, less dominant monkeys, he will
indeed attack the other monkeys when the amygdala is stimulated
- Certain chemicals have been shown to influence aggression: serotonin, a chemical
substance that occurs naturally in the midbrain, seems to have an inhibiting effect on
impulsive aggression. Moreover, in laboratory experiments on normal people, when the
natural production of serotonin is interrupted, aggressive behaviour increases. Therefore,
too little serotonin can lead to increases in aggression
- However, too much testosterone, a male sex hormone can also increase aggression. For
example, prisoners convicted of violent crimes tend to have higher levels of testosterone
than do those convicted of nonviolent crimes. This is consistent with the more general
finding that men are more aggressive than women
- At least one other chemical, alcohol, is associated with increases in aggression; alcohol
acts as a genial disinhibitor, lowering our inhibitions against violent behaviour
- Pain and other physical discomforts (heat) will also increase aggressive behaviour
Situational causes of aggression
- Frustration is a major cause of aggression and it occurs when a person is thwarted on the
way to an expected goal or gratification
- According to frustration aggression theory, people’s perception that they are being
prevented from obtaining a goal will increase the probability of an aggressive response.
This does not mean that frustration always leads to aggression, but it frequently does,
especially when frustration is a decidedly unpleasant experience
- Also, frustration is the result not of relative deprivation, the perception that you (or a
group) have less than you deserve, less than what you have been led to expect, or less
than what people similar to you have. For example, some Canadian policewomen
experienced relative deprivation, they believed that they were excluded from
opportunities and activities that were available to their male colleagues
- One cause of aggression, then, stems from the urge to reciprocate after being provoked by
aggressive behaviour from another person
- Aggression can also be produced by social provocation or the mere presence of an
aggressive stimulus, an object associated with aggressive response (a gun) can increase
the probability of aggression
- Social learning theory holds that we learn social behaviour (aggression) by observing
others and imitating them. For example, a child living in an disciplinary household with
aggressive parents
- The possible effects of viewing violence in the media are of particular interest to social
psychologists because of the pervasiveness of violent programming.
- Violence in the media has been shown not only to lead to greater aggressiveness in the
viewer but also to create a numbing effect, making us more accepting of violence in
society
- There are five distinct reasons that explain why exposure to violence via media might
increase aggression:
1. If they can do it, so can I
2. Oh, so that’s how you do it
3. I think it must be aggressive feelings that I’m experience: watching violence makes
feeling of anger more easily available to
4. Ho hum, another brutal beating, what’s on the other channel: watching a lot of violence
seems to reduce both our sense of horror about violence and our sympathy for the victims
5. It’s better get him before he gets me: if watching a lot of TV makes you think the
world is a dangerous place, you might be more apt to be hostile to a stranger who
approaches you on the street
- The viewing of violent pornographic material promotes greater acceptance of sexual
violence toward women and is associated with actual aggressive behaviour toward
women
How to reduce aggression?
- Punishing aggressive behaviour in order to reduce it is tricky. Punishment can be
effective if it is not too severe and if it follows closely on the heels of the aggressive act
- But severe or delayed punishment is not an effective way to reduce aggression
- Catharsis, the notion that blowing off steam by performing an aggressive act, acting
others engage in aggressive behaviour, or engaging in a fantasy of aggression relieves
built up aggressive energies and hence reduces the likelihood of further aggressive
behaviour
- It is much more likely that committing or witnessing aggression will trigger further acts
of aggression
- Once we have aggressed against someone, we tend to derogate the victim as a means of
justifying our actions. This act of dehumanization makes it more likely that we will
aggress again in the future
- Aggression can be reduced in a number of constructive ways:
- 1. Discussing the reasons for anger and hostility
- 2. Modelling nonaggressive behaviour
- 3. Training people in the use of nonviolent solutions to conflict in communication and
negotiation skills
- 4. Building people’s empathy toward others: building empathy is particularly useful as a
means of thwarting the human tendency to dehumanize one’s victim

Document Summary

Aggression is an intentional behaviour aimed at causing either physical or psychological pain. Hostile aggression is an act of aggression stemming from feelings of anger and aimed at inflicting pain. Instrumental aggression, aggression as a means to some goal other than causing pain. For example, in a professional football game, a defensive lineman will usually do whatever it takes to thwart his opponent (the blocker) and tackle the ball carrier. Sigmund freud, who theorized that human beings are born with an instinct toward life, which he called eros, and an equally powerful death instinct, thanatos, which leads to aggressive actions. Freud believed that aggressive energy must come out somehow, lest it continue to build up and produce illness. Also according to freud, society performs an essential function in regulating this instinct and in helping people to sublimate it, that is, to turn the destructive energy into acceptable or useful behaviour.