Social Psychology
Definition: The scientific study of how we think about, affect, and related to one another.
1. Social Thinking (How do we explain other’s behavior, how do we form our beliefs and
attitudes, and how does what we think affect what we do?)
(a) Attribution theory (Heider, 1958): People tend to attribute other’s behavior either to
their internal dispositions or to their external situations.
-Fundamental attribution theory: A tendency to overestimate the influence of internal
dispositions (i.e., personality) and underestimate the influence of situations in explaining
other’s behavior (“Never judge a person in a situation”).
-The effects of attribution on our behavior: Negative driving  either situational (i.e., he
must be ill) or dispositional attribution (he is crazy)  “safe driving or dirty look.”
(b) Attitudes: Beliefs and feelings that predispose our reactions to objects, people, and
events.
-Our attitudes guide our actions if:
External influences on what we say or do is minimal
The attitude is relevant to the behavior (good health  smoking, Love  yelling at their
mate. Running is good  Only when they do exercise).
We are keenly aware of our attitudes (nit mindlessly follow social expectations or habit)
(c) Do our actions affect our attitudes? Yes!
-The foot-in-the door phenomenon: A tendency for people who agree to a small request
to comply later with a larger one (i.e., salesperson).
-Role-playing: Adopted a new role  Feel like “playing house,” artificial, forced, etc. 
Later, feel natural.
Why actions affect attitudes?
-Cognitive dissonance theory (by Festinger): The tendency to change our attitudes to
reduce the discomfort (dissonance) resulting from inconsistency between our attitudes
and behavior (i.e., Smoking is bad  smoking a lot to act for a play  smoking is not
bad).
2. Social Influence: How do we influence each other? Behavior is contagious!
(a) Conformity
-Chameleon effect: People tend to mimic other’s behavior (confederates’ rubbing face or
shaking foot make participants increase the behaviors)
-Asch, 1955): We tend to go along with what the group agrees (i.e., line size comparison)
-Factors strengthening conformity:
At least 3 group members, when one is made to feel incompetent or insecure, when the
group is unanimous, one admires the groups’ status and attractiveness, when other group
members observe one’s behavior, when one has not prior commitment to other responses,
When one is in a culture values social standards, when the issue is important).
Why do we conform?
-Normative (due to a person’s desire to gain approval or avoid disapproval) vs.
Informational (due to a person’s willingness to accept others’ opinions about reality)
social influence.
3. Obedience:
-Milgran (1965, 1974): Participants (teachers) obeyed to an experimenter and
administered electrical shocks to other participants (learners) (63% to the last switch).
-“I was simply following orders.” “Ordinary people can become agents in a terrible
destructive process.”
-Deception or stressful? Ethical?
4. Group Influence: How do groups affect our behavior?
(a) Social facilitation: In the presence of other people, people tend to perform better (But
no social facilitation if the tasks are difficult and not yet mastered).
(b) Social loafing: The tendency for people in a group to exert less effort when pooling
their efforts toward attaining a common goal that when individually accountable.
(c) Deindividuation: The loss of self-restraint and self-awareness in group situations that
foster anonymity and arousal (Anonymous people can be very mean, aggressive, and
destructive).
(d) Group polarization: The enhancement of a group’s prevailing attitudes through
discussion within the group (Jury decision).
(e) Groupthink: The tendency for people in a decision-making group to desire for
harmony ignoring realistic appraisal of alternatives (i.e., J.F. Kennedy’s decision on
invading Cuba. Groupthink is often subject to group polarization, self-justification,
overconfidence, and conformity.
5. The power of individuals:
(a) Self-fulfilling prophecy: A person’s belief about others or things leads the person to
act in ways that induce the others or things to conform the belief.
(b) Minority influence: The power of committed few individuals can sway the majority of
other group members (especially when the minorities are consistent and confident, and
the majorities are sympathetic).
6. Prejudice: An unjustifiable or negative attitude toward a group or its members.
(Ex) Any two randomly chosen humans are 99.8% alike in the alphabetic sequence in
their genetic code. Only 6% of their 0.2% difference is racial, 9% is ethnic, and 85% is
individual differences within one’s group.
(a) Ingroup: People with whom one shares a common identity.
(b) Outgroup: Those perceived as different from one’s ingroup.
(c) Ingroup bias: A tendency to favor one’s own group.
(d) Scapegoat theory: Prejudice may spring from one’s effort to find a target to blame or
express anger.
(e) Just-world phenomenon: The tendency of people to believe that the world is just and
people get what they deserve and they deserve what they get.
(EX) Bystanders phenomenon, Prejudice, Hindsight bias.
7. Aggression
(a) Testosterone
(b) Alcohol
(c) Frustration-Aggression principle: Being blocked short of a goal  frustrated 
aggression.
(d) Hot temperature (South vs. North. Summer vs. Winter)
(e) Learning (violent games, movies, peers, parents): Not catharsis !!
8. Attraction:
(a) Proximity (geographic nearness): Mere exposure effect: repeated exposure to
novel stimuli increases liking of them)
(b) Similarity
(c) Familiarity
9. Bystander effect: The tendency for any bystander to be less likely to give aid if other
bystanders are present (Notice incident?Interpret it as emergency?assume
responsibility?Help)
10. Social exchange theory: Our social behavior is governed by the aim of maximizing
benefits (i.e., pride, social approval, less guilt) and minimizing costs (time, discomfort,
anxiety) (EX) blood donation.
11. Social trap: A situation in which the conflicting parties become caught in mutually
destructive behavior because each rationally pursued one’s self-interest ignoring
another’s interest and well-being.