Social
Psychology
II
Prosocial Behavior
• Why did people risk
their lives to help
those in Japan after
the earthquake and
nuclear fallout?
• Why do people run
into a burning
building to help
someone?
Prosocial Behavior
- These tragedies show humans have
the potential for prosocial behavior
and altruism
- Prosocial Behavior- a
behavior carried out with
the goal of helping other
people
Prosocial Behavior
- Altruism- prosocial behaviors a
person carries out w/out considering
their own safety or interests
Prosocial Behavior
• What makes people behave this way?
Why do people feel they should risk
their life for others?
• Depends on who “others” are…
- for relatives, altruistic behavior
makes sense, b/c you aid in the
survival of your gene pool
Prosocial Behavior
• What about strangers though?
• Theorists believe in reciprocal
altruism- idea that people
perform altruistic behaviors
b/c they expect others will
perform altruistic behaviors
for them in turn
Prosocial Behavior
- Reciprocal altruism is not only in
humans
- Researchers also found that people
will be altruistic even if they don’t
expect the behavior to be reciprocal
- Evolutionary evidence for altruism
Prosocial Behavior
 women believe
that men who
provide evidence of
altruism would make
better fathers
Prosocial Behavior
• Motives for Prosocial Behavior:
1. Altruism
2. Egoism- perform the behavior for
your own self-interest, to later
receive a favor, or reward
3. Collectivism- perform the
behavior for a larger group the
person is a part of
Prosocial Behavior
4. Principlism- perform the behavior
to uphold moral/religious
principles
5. Empathy-Altruism Hypothesis- feel
empathy toward another 
evoking altruistic motives to
provide help
Prosocial Behavior
- How does this motive affect
prosocial behavior?
- Psychologists demonstrated that
bystander intervention (people’s
willingness to help strangers in
distress) was very sensitive to the
precise characteristics of the
situation
Prosocial Behavior
- However, sometimes people are
slow to help or don’t help at all b/c of
diffusion of responsibility (when more
than one person could help in an
emergency, people assume someone
else will or should help, so they back
off and don’t get involved)
Prosocial Behavior
• Other reasons bystanders fail to help:
1. Have to notice the emergency
2. Label the events as an emergencyhow are other people responding?
3. Must feel responsibility
Aggression and
Prejudice
Aggression
• Why are people aggressive?
- genetic predisposition
- brain & hormone differences
(amygdala)
- serotonin levels
Aggression
• 2 Types of Aggression:
1. Impulsive- reaction to
the situation
Ex. Fist-fight
2. Instrumental- goaldirected, premeditated
Ex. Knock down a lady
for her purse
Aggression
• In what situations do people seem
to be aggressive?
- Frustration-aggression hypothesisfrustration occurs when your goals
are blocked & a rise in frustration
leads to more probability of
aggression
Aggression
- Temperature & Time of Day –
warmer aggression
9pm-3am  aggression
- Direct Provocation/Escalationbelieving the behavior was
intentional is more upsetting
Aggression
• Some cultural constraints to
aggression:
1. More connected you are with
culture/community  less likely to
be aggressive
2. Regional differences- Southerners
have a code of conduct; if you
dishonor it, tend to be more
aggressive
Aggression
3. Modeling- TV and
home life become
the norm
Prejudice
• Prejudice- a learned
attitude, involving negative
fear, negative beliefs
(stereotypes) that justify
that attitude, and
intention to avoid, control,
dominate, or eliminate the
“target object”
Prejudice
• Where does prejudice come from?
1. Social Categorization- people
organize their environment by
categorizing the people around
them
- People divide the world into
“in-groups” & “out-groups”
Prejudice
- “In-groups”groups with which
they identify as
members
- “Out-groups”groups which they
do not identify with
Prejudice
• These distinctions lead to in-group
bias- believing that the group you
are in is better than others
• Leads to societal problems like
discrimination
Prejudice
• The tendency toward
defining “us against
them” becomes more
powerful when
perception grows that
resources are scarce &
that goods can only be
given to one group at the
expense of another
Prejudice
• Prejudice people spend time deciding
who is “us” and who is “them”
- Easy to create, difficult to remove 
leads to discrimination
• Stereotypes- generalizations about a
group of people in which the same
characteristics are assigned to all
members of a group
Prejudice
• Stereotypes encode expectations
that create social realities for people
• Stereotypes are used to produce
behavioral confirmations
- People tend to devalue
information that is inconsistent with
their prior stereotype  thus
difficult to change them
Prejudice
• Stereotypes can lead to stereotype
threat- a stereotyped group’s
knowledge that they must work
against a negative stereotype
Prejudice
• How can we reverse prejudice?
- Contact hypothesis- idea that direct
contact between hostile groups alone
will reduce prejudice  theory has been
disproven
- Mutual dependence, deprovincialization,
& jigsaw techniques work well (ex.
Remember the Titans)