Transcript Is it aggression?

What is aggression?
• Aggression: Intentional behavior aimed at
causing either physical or psychological
pain.
• Key feature: Intention
• Not the same as “assertive” or “ambitious”
• Examples:
– Beer bottle at party
– Drunk driver
Why might people behave aggressively?
• Is aggression inborn?
– Instinct theorists
• Freud: Aggression innate, destructive
– Freud: Death instinct (Thanatos) = innate impulse for
self-destruction. Opposite of life instinct (Eros).
• Lorenz: Aggression innate, but adaptive.
– Ethologist. Emphasized that aggressive instinct
facilitates the individual’s survival, reproduction.
Instinct theories
• Instinct theories are NOT widely accepted.
• Problems with assuming that aggression is
innate
Problems w/Instinct Theories
•
Humans vary greatly in aggressiveness.
– Cross-cultural differences (groups in South
Seas vs. Yanomamo in South American;
Iroquios and social change)
Problems w/Instinct Theories
• Regional differences in aggressive
behavior
– Culture of honor: Homicide rates for males
are significantly higher than those for white
northern males, especially in rural areas. But
this is true only for "argument-related"
homicides.
Culture of honor experiments (Dov Cohen,
Richard Nisbett & colleagues)
• IV: A confederate “accidentally” bumped into the
participant, and called the P an insulting name
(or no incident in the control condition).
• DVs: P’s guess about evaluator’s ratings of his
masculinity; physiological response to stress;
and behavior
• Results: Southerners in insult condition were
more likely than northerners to think they would
be seen as less masculine, experienced
increased cortisol and testosterone, and were
slower to move out of the confederate’s way in a
very narrow passageway.
Problems w/Instinct Theories
• If aggression is a human instinct, then it is
hard to account for this variability both
within and between cultures.
Problems w/Instinct Theories
• Circular reasoning:
– Why do sheep herd? Because they have a
herding instinct.
– Doesn’t explain the phenomenon, just names
it.
Biological influences on aggression
• Neural influences
– AMYGDALA -- associated with aggressive
behavior in humans and in lower animals.
• When electrically stimulated, docile
animals__________________; when neural
activity in the amygdala is blocked
______________become __________.
Neural influences: Interaction
w/environment
– Social factors can influence the impact of
these neural mechanisms.
– EX: If a male monkey is in the presence of
other, _______dominant monkeys, he will
____________the other monkeys when the
_____________is stimulated. But if the
___________is stimulated while the
monkey is in the presence of
______dominant monkeys, he will
____________but will ________instead.
Chemical/hormonal influences
• Testosterone
– Injection of testosterone will
_________aggression in animals
Testosterone in humans
Dabbs and colleagues
• Naturally occurring testosterone levels are higher
among prisoners convicted of violent crimes than
those convicted of nonviolent crimes.
• Once incarcerated, prisoners with higher
testosterone levels violated more prison rules
• Compared fraternities within a given college: those
known to be more rambunctious, less socially
responsible, and more crude had the highest
average testosterone levels.
• Correlational: questions about direction of causality
and third variables
Genetic influences
• Twin studies
• Identical (monozygotic) twins have
identical genetic makeup.
• Fraternal (Dizygotic) twins are no more
similar genetically than any other siblings.
• Twin studies are based on the assumption
that identical twins should show greater
similarity on any trait that is presumed to
be inherited than fraternal twins.
Genetic influences
• Identical twins twice as likely as fraternal twins to
be similar in degree of criminal activity.
• Christiansen: 7000 twins born in Denmark
– ________identical vs.______ fraternal showed
similarity in criminal activity
• Problems:
– __________identical twins ____________similar
records
– Identical twins ___________________than do
fraternal twins.
Genetic/biological vs. environment
• Debate:
• Aggressive behavior results from an interaction
between genetic/biological factors and
environmental factors, but aggression is more
powerfully influenced by genetic and/or
biological factors.
• Aggressive behavior results from an interaction
between genetic/biological factors and
environmental factors, but aggression is more
powerfully influenced by environmental factors.
Heredity vs. environment
• Example: Serial killer, Joel Rifkin
• Researchers examine both environment
and possible genetic basis (look at brain
scans)
– Video clip