Key Social Psychology Experiments

Why This Matters

Social psychology experiments are the backbone of Unit 4, and they appear constantly on the AP Psychology exam. You'll see them in multiple-choice questions testing your recall of specific findings and in FRQs asking you to apply experimental conclusions to new scenarios. These experiments test your understanding of how situational factors, authority, group dynamics, and cognitive processes shape human behavior, often in surprising ways. They don't just describe what people do; they reveal the psychological mechanisms behind obedience, conformity, aggression, and helping behavior.

What makes these studies so exam-relevant is that they challenge common assumptions about human nature. The College Board wants you to understand that behavior isn't solely determined by personality or individual morality. Context matters enormously. As you review each experiment, don't just memorize who conducted it and what happened. Ask yourself: What principle does this demonstrate? How does it connect to concepts like social influence, observational learning, or cognitive consistency? That's the thinking that earns you points.

---

Obedience and Authority

These experiments explore how legitimate authority figures can compel ordinary people to act against their own moral judgments. The key mechanism is the agentic state: when individuals defer responsibility to an authority figure, they become capable of actions they'd otherwise reject.

Milgram Obedience Experiment

• 65% of participants delivered the maximum 450-volt "shock", demonstrating that ordinary people will obey destructive orders from perceived authority figures, even while showing visible distress
• Situational factors increased obedience: proximity to the authority figure, prestige of the institution (Yale University), and physical separation from the "learner" all boosted compliance. When the learner was in the same room, obedience dropped to about 40%. When participants had to physically press the learner's hand onto a shock plate, it dropped further to 30%.
• Agentic state explains the results: participants shifted responsibility to the experimenter ("He told me to do it"), illustrating how diffusion of responsibility operates in hierarchical settings

Stanford Prison Experiment

• Terminated after six days (originally planned for two weeks) due to guards' escalating psychological abuse. Zimbardo's study showed how quickly assigned roles can override personal identity.
• Situational power over disposition: participants were screened for psychological normality beforehand and randomly assigned to roles, yet guards became cruel and prisoners became passive. This supports situational attribution over dispositional explanations.
• Deindividuation contributed to the behavior. Uniforms, numbers instead of names, and the institutional context of a simulated prison all reduced individual accountability.
• Important caveat for the exam: this study has faced serious criticism for lack of experimental control, demand characteristics (Zimbardo acted as both researcher and "prison superintendent"), and a very small sample. You should know it as a demonstration of situational power, but also recognize its methodological limitations.

---

Conformity and Group Influence

These studies reveal how the mere presence of others can alter our perceptions, judgments, and actions. Two mechanisms drive conformity: normative social influence (wanting to fit in and avoid rejection) and informational social influence (assuming others know better, especially in ambiguous situations).

Asch Conformity Experiment

• 75% of participants conformed at least once to obviously wrong answers about line lengths. On any given trial, about one-third of responses were conforming. This demonstrates the power of group pressure even on simple, objective tasks.
• Normative influence was the primary driver. Participants later reported they knew the group was wrong but didn't want to stand out or face social rejection.
• Conformity dropped significantly when even one confederate gave the correct answer. This shows that unanimity is crucial for maximum social pressure. Breaking the unanimous front gave participants "permission" to trust their own eyes.

Robbers Cave Experiment (Sherif)

• Intergroup conflict emerged rapidly between two groups of boys (the Eagles and the Rattlers) through competitive activities like tug-of-war and cabin raids. This demonstrated how easily in-group/out-group bias develops.
• Superordinate goals reduced hostility. Cooperation on shared problems that neither group could solve alone (fixing a broken water supply, pooling money to rent a movie) gradually dissolved group boundaries.
• This is realistic conflict theory in action: competition for limited resources creates prejudice, while interdependence promotes harmony.

---

Observational Learning and Modeling

Bandura's work demonstrated that learning doesn't require direct reinforcement. We acquire new behaviors simply by watching others. This connects directly to Topic 3.9 and the four-step model: attention, retention, reproduction, and motivation.

Bobo Doll Experiment

• Children imitated specific aggressive behaviors they observed in adults, including hitting the inflatable Bobo doll with a mallet, kicking it, and using the same verbal phrases the model had used (like "Sock him in the nose").
• Vicarious reinforcement mattered. Children who saw the model rewarded for aggression were most likely to imitate. Those who saw the model punished were less likely to reproduce the behavior, but crucially, they still learned it. When later offered incentives, they could reproduce the aggressive acts just as well. This distinction between learning and performance is important.
• Challenges strict behaviorist assumptions. Learning occurred without any direct reinforcement to the child, supporting social learning theory over pure operant conditioning.

---

Helping Behavior and Situational Barriers

These studies examine why people sometimes fail to help others in need, revealing that personality matters less than circumstances. Diffusion of responsibility and time pressure are key inhibiting factors.

Bystander Effect (Darley & Latané)

This research was inspired by the 1964 murder of Kitty Genovese, where reports suggested many witnesses failed to intervene (though the original reporting has since been questioned).

• Diffusion of responsibility is the core mechanism. When others are present, each individual feels less personal obligation to act. "Someone else will call for help."
• Pluralistic ignorance compounds the effect. Bystanders look to each other for cues, and if no one reacts, each person assumes the situation must not be an emergency.
• Helping increases when bystanders are alone, when the victim is perceived as similar to them, or when someone else models helping behavior first. These factors reverse the inhibiting effects.

Good Samaritan Experiment (Darley & Batson)

• Time pressure dramatically reduced helping. Seminary students on their way to give a talk stepped over a person slumped and groaning in a doorway. The topic of their talk? The parable of the Good Samaritan.
• Only 10% of rushed participants helped compared to 63% of those who believed they had extra time. Situational factors trumped personal beliefs, demonstrating that context overrides disposition.
• The study also measured participants' religious orientation, but this had almost no effect on helping. The situational variable of being in a hurry was far more powerful than any personality measure.

---

Cognitive Consistency and Attitude Change

Festinger's work revealed that humans are motivated to maintain consistency between their beliefs and actions. When a gap exists, we experience discomfort and will often change our attitudes to resolve it. This connects to persuasion and attitude formation in social psychology.

Cognitive Dissonance Experiment (Festinger & Carlsmith)

• $\$1$ participants rated a boring task as more enjoyable than $\$20$ participants. Why? The smaller payment created greater dissonance between their behavior (telling the next participant the task was fun) and their self-concept (being an honest person).
• Insufficient justification forced attitude change. With $\$20$, participants had an easy external explanation for lying ("I did it for the money"). With only $\$1$, there was no sufficient external reason, so they resolved the dissonance by actually changing their attitude: "Maybe the task really was kind of interesting."
• This counterintuitive finding challenges behaviorist reward principles. Less reinforcement led to more attitude change, demonstrating the power of cognitive motivation over external rewards.

---

Research Methodology and Validity

These studies raise important questions about how we conduct and interpret psychological research. These concepts also appear in the research methods portion of the exam.

Hawthorne Effect

• Participants alter behavior when they know they're being observed. Workers at the Hawthorne Works factory improved productivity simply because they were aware of being studied, not because of any specific change in working conditions.
• Demand characteristics are a related concept: participants may try to behave in ways they think the researcher wants, which threatens internal validity.
• Methodological implication: researchers must control for observation effects. Strategies include naturalistic observation (studying people in their normal environment without their knowledge), deception about the study's true purpose, or single-blind designs where participants don't know which condition they're in.

Rosenhan Experiment ("On Being Sane in Insane Places")

• Eight pseudopatients gained admission to psychiatric hospitals by reporting they heard voices saying "empty," "hollow," and "thud." After admission, they behaved completely normally, yet all were diagnosed with a mental illness (most with schizophrenia).
• Confirmation bias in clinical settings meant that once a label was applied, normal behaviors were reinterpreted as pathological. Taking notes became documented as "writing behavior," a supposed symptom.
• Challenged the construct validity of psychiatric diagnostic categories at the time. The study raised serious questions about whether diagnostic labels reflect genuine conditions or are shaped by institutional expectations and context. (Note: diagnostic systems have been significantly revised since this 1973 study, partly in response to criticisms like Rosenhan's.)

---

Quick Reference Table

---

Self-Check Questions

1. Both the Milgram experiment and the Stanford Prison Experiment demonstrate the power of situational factors. What is the key difference in the type of social influence each study examines?

2. If an FRQ describes a scenario where someone fails to help a person in distress at a crowded mall, which experiment provides the best explanation, and what specific mechanism would you cite?

3. How does the Festinger & Carlsmith finding that $\$1$ participants changed their attitudes more than $\$20$ participants challenge traditional behaviorist assumptions about reinforcement?

4. Compare the Asch conformity experiment and the Robbers Cave experiment: both involve group influence, but what distinguishes conformity within a group from intergroup conflict?

5. A researcher notices that participants in a study about stress seem calmer than expected. Using concepts from the Hawthorne Effect, explain what might be happening and suggest one methodological solution.