Social Psychology

How we think about, influence, and relate to others: the psychology of social behavior.

Core Insight

Fundamental Attribution Error: We overestimate personality and underestimate situation when explaining others' behavior.

  • Someone cuts you off in traffic → "They're a jerk" (personality)
  • You cut someone off → "I was late for an emergency" (situation)

We grant ourselves situational context we deny others.

Social Cognition

How We Perceive Others

First impressions form in milliseconds:

  • Trustworthiness: 100ms
  • Attractiveness: 150ms
  • Competence: 200ms

What drives impressions:

  • Facial features
  • Body language
  • Voice
  • Clothing
  • Context

Halo effect: One positive trait colors perception of other traits

  • Attractive → perceived as more competent, kind, intelligent

Attribution Theory

How we explain behavior:

Attribution TypeExample
Internal (dispositional)"They're lazy"
External (situational)"The job is too hard"
Stable"They're always like that"
Unstable"They were tired today"
Global"They fail at everything"
Specific"They failed at this task"

Actor-observer difference:

  • Actors see situations
  • Observers see personality

Schemas and Stereotypes

Schemas: Mental structures that organize knowledge

  • Helps process information quickly
  • Can lead to errors and biases

Stereotypes: Schemas applied to groups

  • Often contain kernel of truth about group averages
  • Fail when applied to individuals
  • Self-perpetuating through confirmation bias

Social Influence

Conformity

Changing behavior to match group.

Asch conformity experiments: People gave obviously wrong answers to match group

Why we conform:

TypeMotivationExample
InformationalOthers know betterFollowing locals in new city
NormativeWant to fit inLaughing at unfunny joke

Factors increasing conformity:

  • Unanimous group
  • Public response
  • No prior commitment
  • Ambiguous situation
  • Expert or high-status group

Obedience

Following orders from authority.

Milgram experiments (1960s): In the most famous variation, 65% of participants delivered shocks to the maximum level when ordered. Note: later analyses of Milgram's archives and replications have raised serious methodology and ethics concerns (experimenter coercion, variation across conditions, selective reporting). Treat the "65%" figure as suggestive, not definitive.

Why we obey:

  • Socialized to respect authority
  • Gradual escalation
  • Diffusion of responsibility
  • Perceived legitimacy

Resisting harmful obedience:

  • Question authority
  • Recognize gradual escalation
  • Affirm personal responsibility
  • Find allies

Compliance Techniques

TechniqueDescriptionExample
Foot-in-doorSmall request → large requestSign petition → donate money
Door-in-faceLarge request refused → smaller requestAsk for $100, then "just $10"
Low-ballCommit first, costs revealed laterCar price quoted, then fees added
That's-not-allInitial offer, then bonus"Wait, I'll throw in..."
ScarcityLimited availability"Only 3 left!"
Social proofOthers are doing it"Best-selling product"
AuthorityExpert endorsementDoctor recommends
LikingRequest from liked personFriends selling products
ReciprocityAfter giving gift/favorFree sample → purchase pressure

Group Behavior

How Groups Affect Individuals

Social facilitation: Presence of others enhances performance on simple/well-learned tasks, impairs complex/new tasks

Social loafing: Less effort when individual contribution is hidden in group

Deindividuation: Reduced self-awareness in groups → less inhibited behavior

  • Anonymous crowds
  • Online anonymity

Group Decision Making

Groupthink: Desire for harmony overrides realistic appraisal

Symptoms:

  • Illusion of invulnerability
  • Rationalization
  • Belief in group morality
  • Stereotyping outgroups
  • Pressure on dissenters
  • Self-censorship
  • Illusion of unanimity
  • Mind guards

Prevention:

  • Encourage dissent
  • Bring in outsiders
  • Leader speaks last
  • Assign devil's advocate
  • Anonymous input

Group polarization: Group discussion pushes opinions to extremes

  • Moderate liberals → more liberal after discussion
  • Moderate conservatives → more conservative after discussion

Bystander Effect

People may be less likely to help when others are present. The effect is real in many settings, but more recent work (including CCTV analyses of public conflicts) finds bystanders often do intervene, especially in clear emergencies. Treat it as a tendency, not a law.

Why:

  • Diffusion of responsibility
  • Pluralistic ignorance (no one acts → must not be emergency)
  • Evaluation apprehension (fear of embarrassment)

Overcoming:

  • Recognize the effect
  • Point to specific person: "You in the blue shirt, call 911"
  • Take personal responsibility

Prejudice and Discrimination

Definitions

TermDefinition
StereotypeGeneralized belief about group
PrejudiceAttitude (usually negative) toward group
DiscriminationBehavior based on group membership

Sources of Prejudice

Cognitive: Categorization is natural; in-group/out-group thinking automatic

Motivational: Prejudice can serve psychological needs

  • Self-esteem (in-group favoritism)
  • Security (fear of different)
  • Justification (rationalize inequality)

Social: Learned from family, culture, media

Reducing Prejudice

Contact hypothesis: Under right conditions, contact reduces prejudice

Optimal conditions:

  • Equal status
  • Common goals
  • Intergroup cooperation
  • Authority support
  • Opportunity for personal relationships

Other strategies:

  • Perspective-taking
  • Recategorization (expand in-group)
  • Education about biases
  • Institutional change

Relationships

What Predicts Attraction?

FactorDescription
ProximityPhysical and psychological nearness
FamiliarityMere exposure effect
SimilarityAttitudes, values, interests
ReciprocityWe like those who like us
Physical attractivenessEspecially initially
ComplementaritySometimes opposites attract (for specific traits)

Love

Sternberg's Triangular Theory:

ComponentDescriptionAlone =
IntimacyCloseness, bondednessLiking
PassionPhysical attraction, arousalInfatuation
CommitmentDecision to love, maintainEmpty love

Combinations:

  • Intimacy + Passion = Romantic love
  • Intimacy + Commitment = Companionate love
  • Passion + Commitment = Fatuous love
  • All three = Consummate love

Relationship Maintenance

Equity theory: Relationships thrive when perceived inputs and outcomes are balanced

What predicts lasting relationships:

  • Positive-to-negative interaction ratio (5:1)
  • Managing conflict constructively
  • Maintaining friendship
  • Shared meaning and rituals
  • Turning toward bids for connection

Aggression

Types

TypeDescriptionMotivation
HostileImpulsive, angryHarm the target
InstrumentalCalculated, coldAchieve goal
DirectFace-to-face
IndirectGossip, exclusion

Causes

Biological:

  • Testosterone
  • Low serotonin
  • Brain damage (prefrontal cortex)

Psychological:

  • Frustration-aggression
  • Social learning
  • Cognitive interpretation

Situational:

  • Heat
  • Crowding
  • Pain
  • Provocation
  • Alcohol
  • Weapons presence

Reducing Aggression

  • Remove triggers
  • Teach anger management
  • Reduce exposure to violent media
  • Model non-aggressive responses
  • Change interpretations

Prosocial Behavior

Why People Help

MotiveDescriptionExample
Kin selectionHelp genetic relativesParent sacrificing for child
Reciprocal altruismExpectation of returnHelping neighbor who might help back
Social normsReciprocity, responsibilityHelping someone who helped you
Empathy-altruismFeeling for otherHelping distressed stranger
Mood managementFeel good by helpingDonating to feel better

Increasing Helping

  • Make need clear
  • Reduce ambiguity
  • Increase personal responsibility
  • Increase empathy
  • Model helping behavior
  • Reduce costs of helping

Practical Applications

Influence Ethically

Use influence principles for good:

  • Be aware of techniques being used on you
  • Use reciprocity genuinely
  • Build real liking through common ground
  • Use social proof honestly
  • Use authority legitimately
  • Recognize conformity pressure
  • Speak up early to prevent groupthink
  • Assign roles to prevent social loafing
  • Be the one who acts (bystander effect)
  • Value dissent

Build Better Relationships

  • Invest in proximity and familiarity
  • Look for genuine similarity
  • Express liking
  • Maintain equity
  • Manage conflict constructively
  • Turn toward bids for connection

Reduce Personal Bias

  • Acknowledge your biases
  • Seek contact with outgroups
  • Practice perspective-taking
  • Question first impressions
  • Use System 2 for important judgments