P2.S.5Prosocial behaviour and bystander intervention: Piliavin's subway study; the cost-reward model and arousal

Bystander apathy is the well-known finding that people are less likely to help in an emergency when others are present. Latané and Darley (1968) explained it via two mechanisms — diffusion of responsibility (each bystander assumes someone else will act) and pluralistic ignorance (each looks to others to decide whether help is needed).

But some real-world cases buck the trend. Piliavin, Rodin and Piliavin (1969) tested helping in a real environment.

Piliavin's subway study

Procedure: a male confederate "victim" collapsed on the floor of a New York subway carriage between stations (~7 minutes before the next stop). Carriages were chosen with 8–17 passengers. Two confederate observers recorded who helped, when, and from where. The "victim" appeared in two conditions:

• Drunk (smelling of alcohol, carrying a brown paper bag).
• Ill (carrying a black cane).

The race of the victim was also varied (Black or White). 103 trials were run.

Findings

• Help arrived quickly and often: in 78% of trials someone helped before the observer's pre-set 70-second cut-off.
• The ill victim was helped 95% of the time; the drunk victim less often (~50%).
• Help came from the first or nearest person rather than after group deliberation.
• Same-race helping was slightly more common in the drunk condition.
• Diffusion of responsibility was not observed — the size of the carriage didn't reduce helping.

The cost-reward (arousal) model

Piliavin and colleagues proposed that bystanders weigh costs and rewards of helping:

• Costs of helping: time, effort, embarrassment, risk of harm or unpleasantness (e.g. helping a drunk).
• Costs of not helping: guilt, social disapproval.
• Rewards of helping: gratitude, feeling competent, reputation.

When the cost of helping is low and the cost of not helping is high — typical for the ill victim — bystanders help promptly. When costs of helping are high (drunk, smelly, possibly aggressive) helping is reduced.

Physiological arousal triggered by witnessing the emergency motivates action; the cost-reward calculation determines what action.

Strengths

• High ecological validity: real subway, real bystanders, real emergency-like event.
• Challenges the simple "bigger group → less help" model: in the subway, group size didn't matter.
• Generated the cost-reward / arousal account — still influential today.

Weaknesses

• Sample limited to New York subway riders: results may not generalise to rural or quieter settings.
• Ethical concerns: bystanders did not consent and may have been distressed; the team also exposed confederates to repeated unpleasantness.
• Confounds: the carriage layout meant it was hard to ignore the victim; results may not extend to spread-out crowds.
• Definition of "drunk" relied on stereotyped cues; race differences may reflect those stereotypes.