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Concept of the Week · Episode 10
The more people watching something go wrong, the less likely any one of them is to step in. Not because nobody cares, but because everyone is reading everyone else for the cue, and nobody is giving it.
Explained by Professor Peter Kinderman, clinical psychologist · First published 23 September 2026 · Updated 25 September 2026
John Darley and Bibb Latane's experiments from 1968 established the effect after the 1964 murder of Kitty Genovese in Queens, New York, and the New York Times story that 38 neighbours watched and did nothing. That account has since been substantially dismantled, which is the caveat Peter gives on the show, but the laboratory finding held: the more people present at an apparent emergency, the slower and less likely each one is to help. Darley and Latane called the mechanism diffusion of responsibility. Piliavin, Rodin and Piliavin staged collapses on the New York subway in 1969 and found that real crowds were more helpful than the lab suggested, but the social cue, everyone waiting to see what everyone else does, is what Peter builds the week around.
The bystander effect. The more people watching something go wrong, the less likely any one of them is to step in, not because nobody cares but because everyone is reading everyone else for the cue, and nobody is giving it. Peter traces it from the Kitty Genovese story, with the caveat that the 38 witnesses who did nothing has since been shown to be badly overstated, through the staged subway experiments of the 1960s, to the advice he was given as a new lecturer: if the fire alarm goes off, all the students will wait to see what you do, so leave the room. The useful half of the finding is the reverse. Because people are waiting for a cue, the first person who steps forward is usually followed.
Peter's version came from health and safety on his first day as a lecturer. If the fire alarm goes off, all the students will wait to see what you do. Leave the room. On the show it turns into three things. Hilary's story from Brighton, where her teenage son had seen a homeless woman punched in the face with police and a crowd all around and nobody looking at her, and Hilary went back and would not leave until she had seen the woman breathe. The week's AI headline, where the operators of a targeting system and a room of radiologists both did what the bystander does, which is wait for the cue and go along with it. And the Triple T, which is the other half of the finding and the reason it is worth knowing: because people are waiting for a cue, the first person who steps forward is usually followed.
Hear it in context
The bystander effect, AI-mageddon and Burnham meets Trump
If the fire alarm goes off, every student in the room will wait to see what you do. The Concept of the Week is the bystander effect, and the week supplied AI-mageddon, Burnham meeting Trump and a new right to bereavement leave to try it on.
No. That was the New York Times account in 1964, and it has been taken apart since: fewer witnesses saw anything, most saw only fragments, at least two called the police, and one neighbour went down and held her. Peter says on the show that the story might not quite have been exactly as it was presented, and that is right. The experiments the story prompted are a different matter, and they replicated.
Peter's explanation is the social cue. In a group, each person looks to the others to work out whether this is an emergency and whether acting is the done thing. Everyone is doing the same, nobody moves, so not moving becomes the answer. Darley and Latane added diffusion of responsibility: when there are ten people who could act, each one feels a tenth of the obligation.
Go first. Peter's Triple T is make the first move, and it follows straight from the mechanism. If people are waiting for a cue, be the cue. The evidence suggests that once one person steps forward the others tend to follow, and even if they do not, you will have done the right thing. The fire alarm advice works the same way: the lecturer who leaves the room takes the students with them.
The primary literature behind the idea, for anyone who wants to check it. Also on Wikipedia.
Kinderman, P. (2026). The bystander effect. Concept of the Week, Experience: Analysing Newsmakers, episode 10, with Hilary Jeffs. https://www.experiencepodco.com/concepts/bystander-effect.html
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Concept of the Week is a regular feature of Experience: Analysing Newsmakers, the weekly podcast in which clinical psychologist Professor Peter Kinderman and communications expert Hilary Jeffs take the news apart to see what is driving it. Peter picks a psychological idea most of us have half-remembered wrong and explains what it actually shows. New episodes every Tuesday. Where to listen.