Difficulty: Introductory to Intermediate | Prerequisites: Understanding of IV/DV and basic research design (see Part 1 notes).
This unit covers two closely related questions: how do we form impressions of other people, and how do we organise our evaluations of the world? Social perception deals with the snap judgements we make about others, including how much we read from faces, body language and behaviour, and the errors we make when explaining why people act as they do. Attitudes picks up from there: what are attitudes, do they predict behaviour, and what happens when your actions contradict your beliefs? Together, these topics explain the machinery behind first impressions, persuasion and the uncomfortable tension of cognitive dissonance.
We form impressions of others in milliseconds from faces and body language, and we explain their behaviour using attributions that are often biased (especially the fundamental attribution error). Our attitudes have three components (affect, behaviour, cognition) but do not always predict what we actually do. When our behaviour clashes with our beliefs, cognitive dissonance kicks in and we change one or the other to restore consistency.
Person perception / impression formation
The process by which we form overall impressions of other people based on limited information, including their appearance, behaviour and context.
CEO study (Rule & Ambady, 2008)
Participants' snap judgements of CEO faces predicted actual company profits. In simple terms, people inferred competence from faces, and those inferences correlated with real-world outcomes.
Thin slices of behaviour
Brief excerpts of behaviour (sometimes just seconds) that are surprisingly accurate predictors of personality, competence or relationship quality. The idea is that a few seconds of observation carry more signal than you might expect.
Non-verbal behaviour (NVB)
Communication through body language, facial expression, tone of voice, posture, gestures and eye contact, rather than words.
NVB in hierarchy (Kraus et al., 2009)
Kraus and colleagues found that higher-status individuals displayed more disengagement cues (less eye contact, more fidgeting, less nodding) during interactions. Lower-status individuals were more attentive and engaged non-verbally.
Fundamental attribution error (FAE)
The tendency to overemphasise internal, dispositional explanations for others' behaviour and underemphasise situational factors. In simple terms, you assume people do things because of who they are, not because of the situation they are in.
Pro-Castro essay study (Jones & Harris, 1967)
Participants read essays that were either pro- or anti-Castro. Even when told the writer had been assigned a position (no choice), participants still attributed the essay's views to the writer's true beliefs. This is the classic demonstration of the FAE.
Covariation theory (Kelley)
A model of attribution that says people determine causes of behaviour by looking at three types of information: consensus (do others act this way?), distinctiveness (does this person act this way in other situations?) and consistency (does this person always act this way here?).
Culture and attribution (Miller, 1984)
Miller found that American adults made more dispositional attributions than Indian adults, who favoured situational explanations. Younger children in both cultures were similar, suggesting the FAE is partly learned through cultural socialisation.
We form impressions rapidly and with surprising confidence. The CEO study (Rule & Ambady, 2008) showed that naive participants' ratings of CEO faces (on traits like competence and dominance) predicted actual company financial performance. This is unsettling because it means that appearance-based snap judgements carry real consequences.
Thin slices research demonstrates that even a few seconds of observed behaviour can yield accurate personality inferences. The accuracy is not perfect, but it is better than chance, which challenges the assumption that you need extended contact to know someone.
Non-verbal behaviour encodes social hierarchy. Kraus et al. (2009) found that higher-status participants showed more disengagement cues (doodling, fidgeting, less eye contact), while lower-status participants were more attentive. This pattern was observable in brief interactions.
Attribution is the process of explaining why people behave as they do. The two broad categories are:
Dispositional (internal): the person's character, personality or beliefs caused the behaviour.
Situational (external): the circumstances, social pressure or context caused the behaviour.
The fundamental attribution error is the tendency to default to dispositional explanations for others' behaviour. The Jones & Harris (1967) pro-Castro essay study is the textbook example: even when participants knew writers were assigned a position, they still believed the essay reflected the writer's true attitude.
Covariation theory (Kelley) offers a more rational model. You consider:
Consensus: does everyone react this way? (High consensus suggests a situational cause.)
Distinctiveness: does this person react this way only here? (High distinctiveness suggests something about the situation.)
Consistency: does this person always react this way here? (High consistency supports either cause, depending on the other two.)
Culture matters: Miller (1984) showed that the FAE is not universal. American adults favoured dispositional attributions; Indian adults favoured situational ones. Children in both cultures did not differ, suggesting the bias is culturally learned rather than hard-wired.
Explicit attitudes
Conscious, deliberate evaluations of people, objects or ideas that you can report when asked. "I like dogs" is an explicit attitude.
The ABC of attitudes
Attitudes have three components: Affect (feelings), Behaviour (actions) and Cognition (beliefs). A complete attitude involves all three, though they do not always align.
LaPiere (1936) study
LaPiere travelled across the US with a Chinese couple during a period of strong anti-Chinese prejudice. They were refused service only once. But when LaPiere later wrote to the same establishments asking if they would serve Chinese guests, over 90% said no. This is a classic demonstration that attitudes do not always predict behaviour.
Theory of Planned Behavior (Ajzen)
A model that improves attitude-behaviour prediction by adding two factors beyond the attitude itself: subjective norms (what others expect of you) and perceived behavioural control (whether you believe you can actually do it). Together, these three factors shape your intention, which is the best predictor of behaviour.
Cognitive dissonance
The uncomfortable tension that arises when you hold two contradictory cognitions, or when your behaviour contradicts your beliefs. People are motivated to reduce this discomfort, usually by changing an attitude to match the behaviour.
The boring experiment study (Festinger & Carlsmith, 1959)
Participants performed a tedious task and were then paid either $1 or $20 to tell the next participant the task was fun. Those paid $1 later rated the task as more enjoyable. The $1 group lacked sufficient external justification for lying, so they changed their attitude to reduce dissonance. The $20 group had a clear reason (the money), so their attitudes did not shift.
Post-decisional dissonance
Dissonance that occurs after making a difficult choice between two attractive alternatives. People reduce it by upgrading the chosen option and downgrading the rejected one.
Persuasion
The process of changing someone's attitude through communication. Effectiveness depends on factors including the source (who says it), the message (what is said) and the audience (who hears it).
Source credibility and authority (Tormala et al., 2006)
Tormala and colleagues found that a source's perceived expertise and trustworthiness affect how persuasive a message is. A message from a credible source is more persuasive, but certainty about an attitude can be shaken when a credible source disagrees with you.
Implicit attitudes
Automatic, unconscious evaluations that influence behaviour without your awareness. These can differ from your explicit attitudes.
Implicit Association Test (IAT)
A computer-based measure of implicit attitudes. It works by measuring reaction times when pairing concepts (e.g., Black/White faces with good/bad words). Faster pairings suggest stronger implicit associations. The logic is that associations you hold more strongly are easier (and therefore faster) to combine.
The ABC model breaks attitudes into Affect (how you feel about something), Behaviour (how you act toward it) and Cognition (what you believe about it). These three do not always line up, which is precisely why attitudes sometimes fail to predict behaviour.
LaPiere (1936) demonstrated the attitude-behaviour gap dramatically. Establishments that served a Chinese couple in person overwhelmingly said they would refuse service when asked by letter. The situation (a polite couple standing in front of you) overrode the expressed attitude.
The Theory of Planned Behavior addresses this gap. It predicts that behaviour is best predicted by intention, and intention is shaped by three things:
Your attitude toward the behaviour.
Subjective norms: what important people in your life think you should do.
Perceived behavioural control: whether you believe you are capable of doing it.
Dissonance theory (Festinger, 1957) says that people experience psychological discomfort when they hold contradictory cognitions or act against their beliefs. They are motivated to reduce this tension.
Festinger & Carlsmith (1959), the boring experiment: participants paid $1 to lie about a dull task experienced dissonance ("I said it was fun, but it was not, and $1 is not enough to justify lying") and resolved it by deciding the task was actually somewhat enjoyable. Participants paid $20 had sufficient justification and felt no dissonance.
The key principle: less external justification for a counter-attitudinal behaviour produces more attitude change. This is counterintuitive, because you might expect the $20 group to like the task more.
Post-decisional dissonance: after choosing between two attractive options (say, two equally appealing holiday destinations), people spread the alternatives apart. The chosen option starts to seem better and the rejected one worse. This resolves the dissonance of having given up something appealing.
Persuasion research examines who says what to whom.
Source effects: messages from credible, expert or trustworthy sources are more persuasive. Tormala et al. (2006) added a nuance: when a highly credible source disagrees with you, your certainty in your own attitude drops, making you more open to change.
Everyday persuasion examples include advertising, political messaging and health campaigns. The course emphasises recognising the mechanism (source, message, audience) rather than just the outcome.
Implicit attitudes operate below conscious awareness. You may explicitly endorse equality while implicitly associating certain groups with negative attributes.
The IAT measures this by tracking reaction times. If you are faster to pair "White + good" than "Black + good," the IAT infers a stronger implicit association between White and positive.
Implicit and explicit attitudes can diverge. Someone might score high on implicit racial bias while explicitly reporting no prejudice. The relationship between implicit attitudes and actual discriminatory behaviour is a topic of ongoing research and debate.
Students often think the fundamental attribution error means all attributions are wrong. It does not. It means people over-weight dispositional explanations for others' behaviour. Situational attributions can also be incorrect.
Students frequently assume cognitive dissonance always leads to attitude change. It does not. People can also reduce dissonance by adding new cognitions, trivialising the inconsistency, or changing their behaviour.
The LaPiere study is sometimes cited as proof that attitudes never predict behaviour. That overstates the finding. The Theory of Planned Behavior shows that attitudes do predict behaviour, especially when combined with norms and perceived control.
Students sometimes confuse implicit and explicit attitudes as contradictory by definition. They can align perfectly well. The interesting cases are when they diverge.
⚠️ The Jones & Harris (1967) pro-Castro essay study is a near-certain exam question. Know the design, the finding and why it demonstrates the FAE.
⚠️ Be able to apply covariation theory: given a scenario with consensus, distinctiveness and consistency information, determine whether the attribution should be dispositional or situational.
⚠️ The Festinger & Carlsmith (1959) boring experiment is another exam staple. Know why the $1 group changed their attitude and the $20 group did not. The counterintuitive result (less money = more attitude change) is the point.
⚠️ Be ready to explain the attitude-behaviour gap (LaPiere) and how the Theory of Planned Behavior addresses it.
⚠️ The IAT will likely appear. Know how it works mechanistically (reaction-time pairings) and what it measures (implicit associations, not necessarily explicit beliefs).
⚠️ Miller (1984) is useful for any question about cultural variation in attribution.
True or False: The fundamental attribution error applies equally to how we explain our own behaviour and others' behaviour. (False. The FAE primarily applies to others' behaviour. We tend to make more situational attributions for our own actions.)
In covariation theory, high consensus + high distinctiveness + high consistency points to a ________ attribution. (Situational / external.)
True or False: In the Festinger & Carlsmith study, the $20 group showed more attitude change than the $1 group. (False. The $1 group changed more.)
The three components of the Theory of Planned Behavior are attitude, ________ and ________. (Subjective norms and perceived behavioural control.)
True or False: The IAT measures explicit attitudes. (False. It measures implicit attitudes.)
Q: In the Jones & Harris (1967) study, why did participants still attribute pro-Castro attitudes to writers who had been assigned the pro-Castro position?
A: Because of the fundamental attribution error. Participants defaulted to a dispositional explanation ("the writer believes this") even when the situational explanation ("the writer was told to write this") was made explicit. People underweight situational constraints when judging others.
Q: A friend is rude to a waiter. Using covariation theory, what information would you need to determine whether this is dispositional or situational?
A: You would need: consensus (are other people rude to this waiter?), distinctiveness (is your friend rude to other service staff, or only this waiter?) and consistency (is your friend always rude to this waiter, or just today?). Low consensus + low distinctiveness + high consistency suggests a dispositional cause (your friend is just rude). High consensus + high distinctiveness + high consistency suggests a situational cause (something about this waiter).
Q: Why did participants in the $1 condition of Festinger and Carlsmith's study rate the boring task as more enjoyable than those in the $20 condition?
A: The $1 participants lacked sufficient external justification for having told the next participant the task was fun. This created dissonance ("I said it was fun but it was boring, and I was not paid enough to justify lying"), which they resolved by adjusting their attitude to believe the task was somewhat enjoyable. The $20 participants could attribute their lie to the money, so they experienced less dissonance and did not change their attitude.
Q: Explain how the Theory of Planned Behavior improves on the simple attitude-behaviour link demonstrated by LaPiere.
A: LaPiere showed that a single attitude measure ("Would you serve Chinese guests?") poorly predicted actual behaviour. The Theory of Planned Behavior adds subjective norms (social pressure to comply face-to-face) and perceived behavioural control (the difficulty of actually refusing someone standing in front of you), both of which better account for why the establishments served the couple despite their expressed prejudice.
Q: Someone scores high on implicit racial bias on the IAT but reports no prejudice on a questionnaire. How would you explain this discrepancy?
A: Implicit and explicit attitudes operate through different systems. The IAT taps automatic associations formed through cultural exposure and repeated pairings, while the questionnaire measures conscious, deliberate evaluations. A person can sincerely believe they are not prejudiced (explicit) while still holding associations that operate below conscious awareness (implicit).
The fundamental attribution error connects back to automatic vs controlled thinking from Part 1: dispositional attributions are the quick, automatic default, while situational attributions require more effortful processing. Implicit attitudes link directly to the Stereotypes unit (Part 3), because the IAT is one of the main tools used to measure implicit stereotyping and prejudice. Cognitive dissonance also echoes the self-enhancement vs self-verification tension from the Self unit: both involve managing psychological comfort when reality and self-image clash.
Social perception, person perception, impression formation, thin slices, non-verbal behaviour, NVB, body language, hierarchy, Kraus, Rule, Ambady, CEO study, fundamental attribution error, FAE, correspondence bias, Jones, Harris, pro-Castro essay, covariation theory, Kelley, consensus, distinctiveness, consistency, Miller, culture and attribution, dispositional attribution, situational attribution, explicit attitudes, ABC model, affect behaviour cognition, LaPiere, attitude-behaviour gap, Theory of Planned Behavior, Ajzen, subjective norms, perceived behavioural control, cognitive dissonance, Festinger, Carlsmith, boring experiment, $1 $20, post-decisional dissonance, persuasion, source credibility, Tormala, authority, implicit attitudes, IAT, Implicit Association Test, reaction time, automatic associations, NYU London, FA24 midterm, social psychology