Difficulty: Introductory to Intermediate | Prerequisites: Personality Theories and Social Cognition notes (Doc 1 in this series).
This unit examines how other people, whether physically present or simply imagined, influence what we think, feel, and do. It spans conformity, obedience, group dynamics, helping behaviour, aggression, and the mental gymnastics we perform to keep our beliefs and actions aligned (cognitive dissonance). These topics are among the most exam-tested in social psychology because they lend themselves to scenario-based questions. If you are coming in cold, make sure you understand the attribution concepts from the personality and social cognition notes first, as several ideas here build on them.
Social influence research shows that people conform for two reasons (to be liked and to be correct), that groups can boost or undermine individual performance depending on the task, and that bystanders are less likely to help when others are present. Cognitive dissonance theory explains why people change their attitudes to match their behaviour, and related concepts like effort justification and the IKEA effect show how effort warps our sense of value.
Bystander Effect
The tendency for individuals to be less likely to help in an emergency when others are present. In simple terms, the more people watching, the less likely any one person is to step in, because everyone assumes someone else will.
Helper Effect
Seeing someone else help can increase the likelihood that an observer will also help. Think of it as the opposite force to the bystander effect: one person acting breaks the spell of inaction.
Normative Social Influence
Conforming to be liked or accepted by a group, even when you privately disagree. In simple terms, going along to get along.
Informational Social Influence
Conforming because you believe the group has better information than you do. Think of it as looking to others for the right answer when you are unsure.
Social Facilitation
Improved performance on simple or well-practised tasks in the presence of others. In simple terms, having an audience makes you better at things you already know how to do.
Social Loafing
Decreased individual effort in group tasks where personal output is not identifiable. Think of it as coasting because nobody can tell how much you specifically contributed.
Groupthink
Poor group decision-making that occurs when the desire for harmony and conformity overrides realistic appraisal of alternatives. In simple terms, the group agrees on a bad plan because nobody wants to be the one to object.
Prejudice
A negative attitude toward a group and its members. In simple terms, a preconceived negative feeling about people based on their group membership.
Discrimination
Negative behaviour directed toward a group or its members. Think of it as prejudice put into action.
Confederate
An actor in a psychological study who pretends to be a participant but is working with the researcher. In simple terms, a planted "fake participant" used to create a controlled social situation.
Altruism and Prosocial Behaviour
Actions intended to benefit others rather than yourself. These can be motivated by empathy, moral principles, or social norms. Think of altruism as the purest form: helping with no expectation of personal gain.
Aggression
Behaviour intended to harm others. It can be influenced by biological factors (hormones, brain structures), psychological factors (frustration, learning), and social factors (cultural norms, modelling).
Cognitive Dissonance
The mental discomfort that arises from holding conflicting beliefs, or from behaviour that contradicts your beliefs. The discomfort is typically resolved by changing your attitude to match your behaviour. In simple terms, if you do something you believe is wrong, you are likely to adjust your belief rather than admit the contradiction.
Effort Justification
The tendency to value something more highly when you have invested significant effort to obtain it. Think of it as "I worked hard for this, so it must be worth it," even when it might not be.
IKEA Effect
The tendency to overvalue things you have partially created yourself. In simple terms, the bookshelf you assembled yourself feels more valuable than an identical one that came pre-built.
Two routes to conformity
Normative: driven by the need for social acceptance. You go along even if you privately disagree.
Informational: driven by the desire to be correct. You adopt the group's view because you trust their knowledge.
Exam tip: if the scenario involves uncertainty about the right answer, it is informational. If it involves peer pressure or fitting in, it is normative.
Social facilitation vs. social loafing
Facilitation: the presence of others improves performance on simple or well-rehearsed tasks but can impair performance on complex or novel tasks
Loafing: effort drops in group settings when individual contributions cannot be identified
The key variable is identifiability: when your output is visible, facilitation dominates; when it is hidden in the group, loafing dominates
Groupthink
Occurs in cohesive groups with strong leadership and pressure to agree
Symptoms: illusion of invulnerability, self-censorship, pressure on dissenters
Prevention: assign a devil's advocate, encourage independent evaluation, seek outside opinions
Prejudice and discrimination
Prejudice is the attitude (cognitive and emotional); discrimination is the behaviour
Both can be explicit (conscious) or implicit (automatic, below awareness)
Social identity theory: we favour our in-group and derogate out-groups to boost self-esteem
Helping behaviour
Bystander effect: diffusion of responsibility means each individual feels less personal obligation to act
The helper effect works in the opposite direction: seeing one person help encourages others
Factors that increase helping: clear need, personal responsibility, empathy, similarity to the victim
Aggression
Biological: testosterone, serotonin, amygdala activation
Psychological: frustration-aggression hypothesis, observational learning
Social: cultural norms, media exposure, deindividuation in groups
Cognitive dissonance
The discomfort of holding contradictory cognitions motivates change
People typically change the easier cognition (usually the attitude, not the behaviour)
Classic study: participants paid $1 to lie about a boring task rated it more enjoyable than those paid $20, because the small payment was insufficient justification for lying
Effort justification and IKEA effect
Effort justification: the harder you work for something, the more you convince yourself it was worthwhile (a form of dissonance reduction)
IKEA effect: partial creation increases perceived value, even when the finished product is objectively average
Both are downstream consequences of dissonance theory
Groupthink has been used to explain major policy failures (Bay of Pigs, Challenger disaster). The bystander effect has informed public safety campaigns that train people to take personal responsibility in emergencies. Cognitive dissonance is the basis for many persuasion and attitude-change techniques in marketing and public health.
Students often confuse social facilitation with social loafing. Facilitation is about improved performance when others can see you; loafing is about reduced effort when they cannot. The presence of others is not enough on its own to predict the effect.
Students sometimes think the bystander effect means people do not care. The research shows they do care but assume someone else will act. It is a diffusion of responsibility, not apathy.
Students frequently mix up prejudice and discrimination. Prejudice is the attitude (what you feel or think); discrimination is the behaviour (what you do). You can have one without the other.
Students often think cognitive dissonance requires a major moral conflict. Even minor inconsistencies between behaviour and belief can trigger dissonance and attitude change.
⚠️ Be able to distinguish normative from informational social influence in a scenario. This is one of the most common question formats.
⚠️ Know the conditions that increase and decrease the bystander effect (number of bystanders, clarity of emergency, personal responsibility).
⚠️ The $1 vs. $20 cognitive dissonance study is a classic. Expect a question on why the $1 group rated the task as more enjoyable.
⚠️ Understand effort justification as a specific application of cognitive dissonance, not a separate theory.
True or False: Social facilitation improves performance on all types of tasks.
Answer: False. It improves performance on simple or well-practised tasks but can impair performance on complex or novel ones.
Fill in the blank: The tendency to exert less effort when working in a group where individual contributions are not identifiable is called ______.
Answer: Social loafing.
True or False: Cognitive dissonance is typically resolved by changing behaviour rather than attitudes.
Answer: False. People more often change their attitude to match their behaviour, because the behaviour has already happened.
Fill in the blank: ______ is a negative attitude toward a group, while ______ is a negative behaviour toward a group.
Answer: Prejudice; discrimination.
True or False: The IKEA effect is a form of cognitive dissonance.
Answer: True. It reflects dissonance reduction: "I put effort into this, so it must be valuable."
Q: A group of executives ignores warning signs about a failing product launch because no one wants to disagree with the CEO. What concept does this illustrate?
A: Groupthink. The desire for harmony and conformity overrides realistic evaluation of the situation.
Q: You witness a car accident on a busy highway. Despite dozens of drivers passing, no one stops. Which social psychology concept best explains this?
A: The bystander effect. With many people present, each individual experiences diffusion of responsibility and assumes someone else will help.
Q: A student joins a fraternity after a gruelling initiation. Afterwards, he rates the fraternity as more valuable than he did before joining. What concept explains this shift?
A: Effort justification. The student reduces cognitive dissonance by inflating the perceived value of the fraternity to justify the effort he invested.
Q: In Festinger and Carlsmith's classic experiment, why did participants paid $1 report enjoying the boring task more than those paid $20?
A: The $1 group had insufficient external justification for lying, so they experienced greater cognitive dissonance and resolved it by changing their attitude (deciding the task was more enjoyable). The $20 group could justify their lie with the larger payment.
Q: A student conforms to their study group's answer on a difficult question because they are not sure of the correct answer themselves. Is this normative or informational social influence?
A: Informational social influence. The student is conforming because they believe the group may have better information, not because they fear social rejection.
The social influence concepts here connect directly to the attribution biases covered in the personality and social cognition notes. Prejudice and discrimination also relate to the psychological disorders material, particularly where stigma affects help-seeking behaviour. Cognitive dissonance has links to health psychology: people who smoke despite knowing the risks often reduce dissonance by minimising the dangers rather than quitting.
Social influence, conformity, normative influence, informational influence, social facilitation, social loafing, groupthink, bystander effect, diffusion of responsibility, helper effect, prejudice, discrimination, in-group bias, confederate, altruism, prosocial behaviour, aggression, frustration-aggression, cognitive dissonance, Festinger, effort justification, IKEA effect, attitude change, PSY II, Florida International University, Exam 3