Group Inhibition of Bystander Intervention in Emergencies

Darley & Latane (1968) Journal of Personality and Social Psychology

Abstract

What is the study about? What do they want to answer?

Aim - investigate why bystanders fail to intervene in emergencies by testing whether the presence of people (passive) inhibits individuals from reporting dangerous situations.

Hypothesis: Individuals exposed to an ambiguous emergency (smoke filling a room) will be less likely to report it when in the presence of passive others or in groups, compared to when alone.

Theoretical implications

Sample

How many: 24 ppts in alone condition, 10 in the passive confederates condition and 24 ppts (8 groups of 3) in the 3 naive bystanders condition

Age: No age range or ethnicity reported

Demographics: Male undergraduates & graduate and professional students at Columbia University

How were they recruited: contacted by telephone from campus residences and invited to an interview about "problems involved in life at an urban university."

Geographical location: Columbia University, New York

Study method

Lab experiment manipulating the social situation

Procedure

Participants completed a questionnaire in a waiting room when smoke began streaming through a wall vent. Their behaviour was observed through a one-way glass.

Variables

IV - The social condition —

• Alone

• With two passive confederates (trained to notice the smoke but appear indifferent)

• In groups of three naive subjects

DV - Whether participants left the room to report the smoke, and the time taken to do so (measured from when they first noticed it). The experiment was terminated at 6 minutes.

Group comparison - Confederates were instructed to remain uncommunicative and indifferent; report latencies were measured from the moment each subject first noticed the smoke; a hypothetical baseline was mathematically constructed from the alone condition to account for the greater number of people available to report in groups.

prediction of what would happen

Where did the study take place?

Lab

Control over CVs?

Confederates were instructed to remain uncommunicative and indifferent; report latencies were measured from the moment each subject first noticed the smoke; a hypothetical baseline was mathematically constructed from the alone condition to account for the greater number of people available to report in groups.

Results

• Alone condition: 75% reported the smoke (median under 2 minutes).

• Two passive confederates: Only 10% reported the smoke (1 of 10 subjects) — highly significant vs. alone ().

• Three naive bystanders: Only 38% of groups had even one person report the smoke, whereas the expected rate (if people had no influence on each other) was over 98% (). Only 3 of 24 participants reported it during the whole period.

Additional finding: People in groups noticed the smoke more slowly — 63% of alone subjects noticed within 5 seconds vs. only 26% in the together conditions — attributed to the social constraint of not appearing inquisitive.

Interpretation: The results support the predictions. However, the authors note alternative explanations — e.g., participants in groups might feel less personally threatened by the fire, or the "togetherness" effect (Schachter, 1959) might reduce fear. They also found that non-reporters reinterpreted the smoke as non-dangerous (steam, smog, "truth gas"), and almost all claimed they paid no attention to others — despite the strong effect of their presence.Missing from the abstract: The abstract states the mediation by interpretation, but omits the noticing-latency finding, the alternative explanations, and the participant demographics/limitations.

Measures and materials: The smoke (titanium dioxide) was clearly visible and progressively obscured vision, yet the dependent variable was a single binary outcome (report or not) plus latency — relatively simple but well-suited to the question.

Alternative explanations: The authors themselves raise several — reduced personal threat in groups, fear-reduction via togetherness, and the possibility that subjects' self-reports (claiming to ignore others) undermine the social-influence explanation. One could also question whether the confederates' studied indifference created an artificial situation unlike real groups.

Historical context: Published in 1968, shortly after the 1964 Kitty Genovese murder (38 witnesses, no action), which galvanised research on bystander apathy. This paper is part of the foundational wave of bystander-intervention research in the late 1960s, amid broader social concern about urban alienation and public morality in America.

Evaluation