The Bystander Effect (Definition + Examples)

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Practical Psychology

Anyone who has been through high school or college knows that group projects are the worst. It always seems like no one is pulling their weight and someone has to step up and put most of the work on their shoulders. 

Why does that always happen? 

Psychologists might say that it has something to do with The Bystander Effect. But the Bystander Effect isn’t just a phenomenon that happens in the college classroom. It happens in cities, crowds - and even crime scenes. 

What Is the Bystander Effect? 

The Bystander Effect is the idea that as a bystander, you are less likely to intervene or take action when you are surrounded by others. People are less likely to provide assistance to another person if they feel that they are in the presence of a crowd.

Where Did the Bystander Effect Come From? 

The Bystander Effect has been a subject of studies since the 1960s. Many psychologists believe that research on the Bystander Effect started with the murder of Kitty Genovese.

Genovese was murdered outside of her apartment at 3 a.m. in 1964. Two weeks later, the New York Times published an article titled “37 Who Saw Murder Didn't Call the Police.” The headline shocked the world. How could 37 people fail to take action when something so horrific was happening? Did this mean cities like New York were extra dangerous? Do people not have compassion? 

These are some of the questions that psychologists have been trying to answer since the 1960s. 

Diffusion of Responsibility 

How do people explain their inaction? In the case of Kitty Genovese, media sources said that witnesses just “didn’t want to get involved.” But social psychologists have a more scientific way to explain why The Bystander Effect occurs. 

Attribution is the study of how people explain causes and effects. The Diffusion of Responsibility is a form of attribution that is often used to explain “bystander apathy.” When people are in a large group, responsibility to take action is diffused throughout the entire group. This reduces each individual’s responsibility and decreases their motivation to act. 

For example, if you are the only person witnessing a robbery, you are the only person who has a responsibility to stop the crime or report it to the police. If you are in a crowd and witness a robbery, you are one of many people who could potentially stop the crime or report it to the police. When the same responsibility is “diffused” among a larger group of people, everyone is more likely to say, “They’ll do it.” Each person may even mentally “assign” the responsibility to someone in the crowd who looks more capable or “should” take action. 

Bystander Effect Experiments Examples

Four years after the Kitty Genovese murder, two social psychologists conducted multiple studies on The Bystander Effect. John M. Darley and Bibb Latané set up different scenarios in which subjects would see or hear a possible emergency. Subjects would either be alone, with a small group of people, or with a larger group of people. The researchers would then record whether or not the subject reported the incident. 

Take their first experiment. The researchers gave the subjects a questionnaire to fill out in a room. They left the room and began to fill it with smoke. 

In one room, the subject was entirely alone. In another room, three other people sat in the room and ignored the smoke. In the last room, three other people sat in the room and two visibly noticed the smoke and ignored it. 

Here are the results. 

75% of the participants who sat in the room alone got up to report it to someone in the building. Only 38% of participants sat in the room with three people who failed to see the smoke reported the smoke. Even more shocking, 10% of the participants who sat in the room with people who acknowledged and ignored the smoke reported what they saw. 

How the Bystander Effect’s History Affects How We View It 

It’s been over 50 years since Kitty Genovese’s murder. The New York Times headline that shocked the world has since been revealed as a fraud. (While 38 people gave statements to the police about hearing something, there were not 37 eyewitnesses to Kitty’s murder. And multiple calls were made to the police regarding Kitty’s screams.) 

Bystander Effect Example: Khaseen Morris

But the research regarding The Bystander Effect still proves to be an uncomfortable look at how we distribute responsibility and excuse our inactions. Cases of The Bystander Effect continue to make headlines in newspapers and online. In September 2019, a 16-year old named Khaseen Morris was stabbed to death while in a fight outside of a strip mall. Dozens of people witnessed the teen’s death. Many even filmed the fight and broadcast it over Snapchat. But no one intervened. (Eight people are in jail over the teen’s death.) 

Brain development, cultural norms, and other factors may all play a role in why people don’t intervene when an emergency is taking place. There is more research to be done on The Bystander Effect, and sometimes attribution varies case by case. But what we do know is that stories like Kitty Genovese or Khaseen Morris shock (and often disgust) the world. Failing to take action paints a picture of a world where people naturally lack compassion and tolerate suffering. And for most people, this is not a world that they do not want to live in. 

How to Overcome the Bystander Effect 

The knowledge of the diffusion of responsibility or the Bystander Effect may help you consciously make better decisions when you witness an emergency, or just work in a group project. If you catch yourself saying that you “don’t want to get involved,” or stand around waiting for someone else to take action, remember that you are being a bystander.

Take action when you see wrongdoing. Report things before waiting for someone else to report them. Assign someone to call 911 so they know it is their responsibility. You just might save someone’s grade in your college class - or someone’s life.

Reference this article:

Practical Psychology. (2019, December). The Bystander Effect (Definition + Examples). Retrieved from

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