Difficulty: Intermediate | Prerequisites: Week 9 (Emotions), basic understanding of cognitive dissonance and Social Identity Theory.
Persuasion is a deliberate, intentional attempt to change someone's attitudes, beliefs, or behaviour. This week covers why persuasion is difficult (our folk psychology resists it), how cognitive dissonance can be harnessed as an indirect persuasion tactic, the four functions attitudes serve, and the Elaboration Likelihood Model's two routes of influence. If you have not reviewed cognitive dissonance or Social Identity Theory from earlier weeks, revisit those first. This material builds directly on emotional arousal (Week 9) and feeds into understanding prejudice reduction (Week 13).
Persuasion is an intentional act aimed at shifting someone's stance. It is hard because our attitudes are maintained by motivated reasoning and epistemic double standards rooted in Social Identity Theory. Attitudes serve four functions (utilitarian, ego-defensive, value-expressive, knowledge), and lasting attitude change requires replacing the same function. The Elaboration Likelihood Model describes two routes: the Central route (logic, evidence, personal relevance) and the Peripheral route (source attractiveness, emotional framing, heuristics).
Persuasion
An intentional act aimed at changing someone's beliefs, values, or attitudes to achieve a goal. Distinguished from other social influence by its deliberate, goal-directed nature. In simple terms, persuasion is when someone is actively trying to change your mind about something.
Elaboration Likelihood Model (ELM)
A dual-process model of persuasion proposing two routes by which messages can change attitudes: the Central/Systematic route and the Peripheral/Heuristic route.
Central/Systematic Route
The persuasion pathway where the recipient attends carefully to the message content, evaluates evidence, and considers logic in detail. Related to System 2 thinking. Activated when the message is personally relevant, the person has domain knowledge, or feels personally responsible. Persuaded by strong, high-quality arguments.
Peripheral/Heuristic Route
The persuasion pathway where the recipient attends to superficial cues rather than message content. Related to System 1 thinking. Activated when motivation is low, the person is distracted or tired, or lacks ability to process deeply. Persuaded by source attractiveness, number of arguments, emotional framing, and appearance of consensus.
Utilitarian Function (of attitudes)
Attitudes adopted because they are personally rewarding or help avoid punishment. Held in one's own self-interest. Think of it as: "I hold this attitude because it benefits me."
Ego-Defensive Function
Attitudes maintained because they protect the person from psychological harm through defence mechanisms (denial, projection, repression). Related to Downward Comparison Theory, where derogating a less fortunate other increases one's own subjective well-being.
Value-Expressive Function
Attitudes that express one's group's central values or beliefs. They establish identity, gain social approval, and signal what the person stands for. Important for affirming group membership.
Knowledge Function
Attitudes that shape behaviour both directly (compelling obvious responses) and indirectly (through knowledge structures and self-concept), maintaining consistency between beliefs.
Downward Comparison Theory
The view that derogating a less fortunate other increases our own subjective well-being. Correlates with the ego-defensive function of attitudes.
Source Characteristics
Properties of the person delivering a persuasive message that affect its credibility: expertise, trustworthiness, attractiveness, and status/prestige.
Message Characteristics
Properties of the persuasive message itself that affect its effectiveness: message quality, vividness, fear-evoking content, and cultural familiarity/significance.
Receiver Characteristics
Properties of the message recipient that modify how persuasion is received: need for cognition, current mood, and age-specific effects (cohort effects and teenage novelty-seeking).
Cohort Effects
As people age, things reminiscent of the world they grew up in gain automatic positive attitude valence. Older adults respond positively to familiar cultural touchstones.
Novelty Effects
Young people, especially teenagers, are drawn to novel stimuli, making novelty a particularly effective persuasion tool for this demographic.
Persuasion is an intentional act, aimed at changing someone's stance. This distinguishes it from other forms of social influence (conformity, obedience) which may not be deliberate.
Understanding the belief, value, and attitude differences between the persuader and target, along with the persuader's intentional goals, are the keys to understanding success or failure.
We tend to recall acts of persuasion as overly favourable to ourselves, making it hard to study persuasion accurately through self-report.
Attitudes are difficult to shift with direct appeals, partly because of epistemic gaps identified through Social Identity Theory:
Informational: we only trust information from people we believe share our inter-subjective worldview
Normative: negative social judgement has no sting unless we share or respect the group identities involved
Evaluations are motivated. We apply an epistemic double standard (scrutinising opposing views far more carefully than agreeable ones). Persuasion works by disarming these specific attitude-maintenance processes.
Cognitive dissonance is a key tactic in indirect persuasion: highlight a mismatch between an existing attitude and some other attitude, belief, or behaviour. The person is far more likely to change their stance spontaneously to resolve the dissonance.
Situational justifications people use to escape dissonance tension: external justification ("I was forced"), not freely chosen, reversible, or effects self only.
Attitudes are cognitive intermediaries between beliefs and actions. They serve four distinct functions:
Utilitarian Function: attitudes adopted because they are personally rewarding or help avoid punishment. Held in self-interest.
Ego-Defensive Function: attitudes that protect the person from psychological harm via defence mechanisms (denial, projection, repression). Correlates with Downward Comparison Theory.
Value-Expressive Function: attitudes that express one's group's central values, establish identity, and gain social approval. Critical for affirming group membership.
Knowledge Function: attitudes that maintain consistency between beliefs and shape behaviour both directly and indirectly through knowledge structures and self-concept. Changing attitudes at this level is one of the most effective means of changing behaviour unobtrusively.
When attempting to change someone's attitudes, consider what functional work the attitude performs in their psychological life.
If the new attitude cannot fulfil the same functional role, the person is likely to revert spontaneously.
Cialdini's six persuasion principles: Authority, Likeability, Reciprocity, Consistency, Consensus, Scarcity.
Central/Systematic Route (related to System 2):
The recipient attends carefully to the message, considers relevant evidence and underlying logic in detail.
Activated when the message is personally relevant, the person has knowledge in that domain, or the message evokes personal responsibility.
People are more persuaded by high-quality (logical) arguments via this route.
Peripheral/Heuristic Route (related to System 1):
The recipient attends to superficial aspects of the message.
Activated when motivation or interest is low, the person is distracted or tired, or lacks the ability to process deeply.
People are persuaded by source characteristics (attractiveness, credibility), message characteristics (number of arguments, emotional framing, whether conclusions are explicit), and the appearance of consensus.
All contemporary advertising theories follow a common structure built around three categories of characteristics:
Source Characteristics (who the message comes from):
Expertise: we suspect they know what they are talking about
Trustworthiness: their track record vs. any obvious incentive to lie
Attractiveness: we are naturally drawn to emulate attractive people
Status/Prestige: are they a "big deal" in a relevant area or field?
Message Characteristics (what is said, and how well):
Message quality: sound reasoning, clarity, strength of evidence
Vividness: how immediately memorable, catchy, or narrative-driven it is
Evoking fear: provokes action by showing how to "escape" a threat
Cultural familiarity/significance: ingroup favouritism, ideology
Receiver Characteristics (what the recipient brings to the table):
Need for cognition: people vary in their baseline preference for detail and complexity
Mood: we are less critical when our mood has been shifted
Age-specific effects: cohort effects (older adults respond to familiar cultural touchstones) and novelty effects (teenagers are drawn to the new)
The ELM explains why the same advertisement can work on one audience and fail on another. Political campaigns use the peripheral route heavily (celebrity endorsements, emotional appeals), while policy debates aim at the central route. Activity changes in the medial prefrontal cortex at the time of exposure to persuasive content can predict whether a person will eventually be convinced, even before they consciously change their mind.
Students often think the Central and Peripheral routes are about whether the message is logical vs. emotional. The distinction is about the recipient's processing mode, not the message content. A logical argument processed superficially still goes through the peripheral route.
The four functions of attitudes (utilitarian, ego-defensive, value-expressive, knowledge) are not mutually exclusive. A single attitude can serve more than one function, but lasting change requires addressing the primary function.
Cognitive dissonance is not a persuasion technique in itself. It is a psychological state. The technique is deliberately highlighting a mismatch so the target experiences dissonance and resolves it in your favour.
Students sometimes assume persuasion always means direct argument. The course emphasises that indirect persuasion (via dissonance, identity, heuristics) is often more effective.
⚠️ Know the four functions of attitudes (utilitarian, ego-defensive, value-expressive, knowledge) and be able to explain each in one sentence.
⚠️ Be able to compare the Central and Peripheral routes: what activates each, and what persuades through each.
⚠️ The four source characteristics (expertise, trustworthiness, attractiveness, status/prestige) are commonly tested.
⚠️ Know the situational justifications for escaping cognitive dissonance: external justification, not freely chosen, reversible, effects self only.
⚠️ The medial prefrontal cortex finding (brain activity at time of exposure predicts later persuasion) is a memorable exam detail.
True or False: Persuasion is any form of social influence. (False. Persuasion is specifically intentional and goal-directed.)
Fill in the blank: The four functions attitudes serve are utilitarian, ego-defensive, ______, and knowledge. (Value-expressive.)
True or False: The Central route is activated when motivation is low and the person is distracted. (False. That activates the Peripheral route.)
Fill in the blank: According to the course, lasting attitude change fails when the new attitude cannot fulfil the same ______ role as the old one. (Functional.)
True or False: Source attractiveness is most effective through the Central route. (False. It works through the Peripheral route.)
Q: How does persuasion differ from other forms of social influence?
A: Persuasion is an intentional act, aimed at changing someone's stance.
Q: What are the four functions attitudes can serve in social life?
A: Utilitarian, ego-defensive, value-expressive, and knowledge functions.
Q: What does it mean to say an attitude serves a utilitarian function?
A: Holding the attitude benefits the interests or worldview of the person.
Q: What does it mean to say an attitude is ego-defensive?
A: The attitude supports some defence mechanism and maintains self-esteem.
Q: What does it mean to say an attitude is value-expressive?
A: It expresses or aligns with a core value of one's ingroup, serving as a social signal of commitment or loyalty when activated.
Q: What are the two routes of influence in the Elaboration Likelihood Model?
A: The Central/Systematic Route and the Peripheral/Heuristic Route.
Q: What characteristics of a message activate the Central route?
A: Personal relevance, existing knowledge about the issue, or feeling personally responsible. The person is convinced by strong arguments.
Q: What characteristics of a message work on the Peripheral route?
A: Activated when motivation or interest is low, or the person is distracted or tired. Convinced by appeal or expertise of source, emotional framing, number/length of arguments, and the appearance of consensus.
Q: What characteristics make a spokesperson more appealing?
A: Apparent expertise, sense of trustworthiness/familiarity, general attractiveness, and signs of status or prestige (especially within the ingroup).
Q: Can activity changes in the medial prefrontal cortex at time of exposure predict if you will ever be convinced?
A: Yes.
This connects to Emotions (Week 9) because emotional arousal and fear-evoking content are key message characteristics in the peripheral route. It connects to Relationships (Weeks 11-12) because attitudes about romantic partners, commitment, and social norms are maintained through the same functional processes described here. It connects to Prejudice (Week 13) because prejudice reduction strategies often work by triggering cognitive dissonance or by shifting the functional role of a prejudiced attitude.
Persuasion, advertising, attitude change, attitude functions, utilitarian function, ego-defensive function, value-expressive function, knowledge function, Elaboration Likelihood Model, ELM, central route, systematic route, peripheral route, heuristic route, System 1, System 2, source characteristics, message characteristics, receiver characteristics, expertise, trustworthiness, attractiveness, status, prestige, message quality, vividness, fear appeal, cultural familiarity, need for cognition, mood and persuasion, cohort effects, novelty effects, cognitive dissonance, indirect persuasion, Downward Comparison Theory, Cialdini, authority, likeability, reciprocity, consistency, consensus, scarcity, medial prefrontal cortex, PSY 301, social psychology, NYU