Beyond the Kitty Genovese case, John Darley and Bibb Latané conducted systematic laboratory experiments throughout the late 1960s to map the exact conditions under which bystanders help — or fail to.

The Smoke-Filled Room Study

Participants were left in a room that slowly filled with smoke from a vent. Alone, 75% reported the smoke within 2 minutes. In groups of three strangers (all real participants), only 38% reported it within 6 minutes — with some sitting in smoke so thick they could barely see, calmly completing questionnaires.

The Epileptic Seizure Study

Participants heard another person (via intercom) begin having a seizure. When they believed they were the only one who could hear: 85% helped within 60 seconds. When they believed four others also heard: 31% helped.

The Variables That Increase Helping

• Clear responsibility (being alone)
• Knowing the victim
• Similarity between helper and victim
• Prior emergency first-aid training
• A small number of bystanders

Universal Application

In any emergency with bystanders, assume diffusion of responsibility is operating. Assign specific individuals to act.

Reference:

Wikipedia: Bystander Effect

https://en.wikipedia.org/wiki/Bystander_effect