Core studies: Piliavin et al. (1969) subway study of helping behaviour and Haney, Banks and Zimbardo (1973) Stanford prison study, including their aims, methods, results, conclusions and evaluation.

What this dot point is asking

Edexcel names two core studies for Topic 5: Piliavin et al. (1969), the subway field experiment on helping behaviour, and Haney, Banks and Zimbardo (1973), the Stanford prison study on social roles. Know each study's aim, method, results and conclusion, and evaluate them, including their ethics.

Piliavin et al. (1969): the subway study

The aim was to investigate the factors affecting helping behaviour in a real-life emergency, including the type of victim and the presence of others.

The method was a field experiment on a New York subway train. A male confederate collapsed during the journey, and the researchers varied how the victim appeared: sometimes ill (carrying a cane) and sometimes drunk (smelling of alcohol and carrying a bottle). Observers recorded who helped, how quickly, the number of helpers and bystanders, and other details.

The results showed the apparently ill victim (with the cane) was helped far more often and more quickly than the apparently drunk victim. Helping was generally fast, and the bystander effect was weaker than in lab studies. The conclusion supported a cost-reward model: people weigh the costs of helping (effort, danger, unpleasantness) against the rewards (approval, reduced discomfort), so they help less when the cost is high (a drunk victim seen as less deserving and more unpleasant).

Evaluation. Strengths: high ecological validity (a real subway, so realistic behaviour) and no demand characteristics because participants did not know they were in a study. Weaknesses: poor control of variables (a field setting), and ethical concerns, since bystanders did not consent and may have been distressed.

Haney, Banks and Zimbardo (1973): the Stanford prison study

The aim was to investigate whether people conform to social roles, by seeing how ordinary people behave when assigned the role of guard or prisoner.

The method was a controlled observation in a mock prison in a university basement. Male student volunteers were randomly assigned to be guards or prisoners. Prisoners were "arrested", given uniforms and numbers; guards were given uniforms, sunglasses and authority. Their behaviour was observed.

The results were that participants quickly took on their roles: many guards became aggressive and abusive, and prisoners became passive, anxious or distressed, with some showing extreme stress. The planned two-week study was stopped after six days. The conclusion was that people conform strongly to social roles, even when this leads to harmful behaviour, suggesting the situation (the role) powerfully shapes behaviour.

Evaluation. Strengths: high impact and real-world relevance (helping explain abuse in institutions). Weaknesses: serious ethical problems (psychological harm, inadequate protection), a small, unrepresentative sample of male students, possible demand characteristics (participants acting out stereotypes), and Zimbardo's dual role as researcher and prison superintendent reducing objectivity.

Linking the studies

Try this

Q1. What did Piliavin vary about the victim on the subway? [1 mark]

• Cue. Whether he appeared ill (with a cane) or drunk (with a bottle and smelling of alcohol).

Q2. Why was the Stanford prison study stopped early? [1 mark]

• Cue. Guards became abusive and prisoners became too distressed, raising serious ethical concerns.

Q3. Explain one ethical weakness of the Stanford prison study. [2 marks]

• Cue. Participants suffered psychological harm and were not adequately protected, and Zimbardo's dual role reduced objectivity.