What Is The Bystander Effect And Is It Dangerous?

Medically reviewed by Andrea Brant
Updated December 14, 2023by BetterHelp Editorial Team
Content Warning: Please be advised, the below article might mention trauma-related topics that could be triggering to the reader. Please see our Get Help Now page for more immediate resources.

Many of us have been in situations where someone is being harmed, having a medical emergency, or otherwise calling out for someone to come to their rescue. But how many of us have stepped in to help? 

When surrounded by a group of people, it can be easy to assume that the person to your right or left will jump in and offer assistance during times of need. Even as time passes and no one makes a move, you may still wait around, thinking that surely someone will help. This phenomenon is known as the bystander effect.

Keep reading to learn more about the origin of the bystander effect and its impact on society.

Need Support After Experiencing A Traumatic Incident?

The Origins Of The Bystander Effect

Years ago, researchers set out to understand what would later be called the bystander effect. Interest in this phenomenon started in 1964 after Kitty Genovese was raped and murdered in Queens, New York. There were multiple witnesses who both heard and saw the crime, but no one intervened or called the police.

Scientists wanted to know what had happened and why no one tried to help. This strange case of group psychology was subsequently studied and researched for years and even became a well-known reference in books and movies.

Defining The Bystander Effect

Scientists define the bystander effect as a phenomenon that occurs in groups of people where they all resist the notion of helping as individuals. The group allows the event to occur even though they're aware of it. Researchers soon learned that the larger a crowd is, the more likely it is that no one will act when someone is hurt. 

The reasons behind the bystander effect have interested psychologists for years. In Kitty Genovese's case, calling the bystander effect "apathy" would be inaccurate. Onlookers can be sympathetic and even desire to intervene and offer help. However, due to many potential factors, they don't act on these desires. People who are bystanders in tragic or urgent situations may even feel guilty for it later, believing they should have done more.

Is The Bystander Effect Dangerous?

Given that the bystander effect can keep people from intervening in emergency situations, it can pose a danger to society—particularly to individuals who are most vulnerable. However, because getting involved in any unfamiliar situation can pose risks to bystanders, it is possible that the bystander effect keeps other people safe. For example, getting involved in a medical emergency versus a violent crime can pose different risk levels for the individual who jumps in to help.

Mob Mentality And The Bystander Effect

There have long been general observations of mob mentality and what experts call "group mind," which psychologists Gabriel Tarde and Gustave Le Bon discussed. However, the Kitty Genovese case was so notorious that it prompted an official laboratory-based study by John M. Darley and Bibb Latané in 1968. According to their research, the presence of a large group of people inhibits individuals from taking decisive action.

Latané even staged a  one year later. An experimenter met with participants either alone or in groups of two. She then left the room and played a recording that simulated a fall and subsequent injury. Of the participants who heard the fall while alone, 70% offered to help. Of those who were paired with another participant, only 40% offered to help. 

A less extreme example of the same dynamic might be when children in a class deliberately don’t ask the teacher additional questions, even if the teacher asks them if they have questions or if they know they may fail a test. They likely fear being perceived as different from others who aren't asking for help. Similarly, if everyone in a significant group witnesses a crime and no one steps forward, the group often starts to think it may not be an emergency after all.

Another powerful dynamic is what psychologists call diffusion of responsibility. In one study, a group of people was asked to wait in a room together, and they observed smoke rising from underneath the door. Surprisingly, the more people in the room, the fewer individuals spoke up about the smoke. These studies shed light on another possible motivation: many people may not speak up because they don't want to accept responsibility for taking a specific action.

Evolution And The Bystander Effect

This diffusion of responsibility may be linked to humans’ evolutionary development. Latané's studies mention that the degree of emergency is determined by each bystander who goes through a variety of cognitive and behavioral processes. These individuals interpret the scene and gauge their level of responsibility in acting or holding back. Latané also notes that these processes include variables such as whether the person deserves help, whether they can help themselves, and what obligation is owed to the person in need based on their relationship with the bystander. In some cases, a lack of connection to the individual in distress may play a part in a bystander’s decision.

More Bystander Effect Examples

Another aspect of the bystander effect may be the intimidation factor, which often comes into play in instances of bullying. The intimidation factor refers to the idea that people may be more likely to back down from intervening if they sense that acting would put them in the path of the same danger they observe.

Another theory that might explain inaction would be how well the observer understands the environment, including the streets, exits, sources of help, etc. If they are in an unfamiliar setting, it may be more difficult to help because of an instinct of self-preservation.

Another motivation may be group cohesiveness. The more cohesive a group, the more likely people typically are to react as a unit. Police officers are expected to intervene in most dangerous situations, not only because it's their job but also because police officers work as a cohesive force.

Altruism, the act of playing the hero even if it's just temporarily, seems more likely to occur if the hero sees similar traits in the person he's rescuing. This can make the individual in distress seem familiar, and a simulation of cohesiveness is attained. This may explain why many did not intervene in Genovese's case since, in large cities (where nighttime is perceived as dangerous and unwelcoming), people are often unacquainted with each other. Thus, sympathy may be minimal or absent.

Seeking Support As A Bystander With Online Therapy

The emotions that can arise after being involved in a bystander situation can create challenging emotions, such as guilt, shame, and sadness. If you're having trouble processing your feelings or moving forward, you may benefit from speaking with a licensed counselor. If trauma makes it difficult to leave home to see a therapist, you might consider online therapy. 

With online therapy through a platform like BetterHelp, you can discuss past traumas from home or anywhere you feel safe. The option of communicating with your therapist through video chats, phone calls, or live chat may help you feel more comfortable to talk during therapy sessions.

Need Support After Experiencing A Traumatic Incident?

The Efficacy Of Online Therapy For Bystander Guilt

Those who have witnessed a traumatic event may be experiencing bystander guilt, which can occur when a person feels bad about what happened to someone else or wishes they had done more to assist. Studies have shown that therapy can be a useful intervention for concerns such as guilt. In one study published in Current Treatment Options in Psychiatry, researchers found that trauma-informed guilt reduction therapy was effective in “reducing guilt that is common to moral injury as well as PTSD and depression symptoms among combat veterans.” 

If you need help moving past feelings of guilt, it could be beneficial to connect with an online therapist for support. Online therapy has been shown to be equally as effective as in-person therapy, and it gives participants the option to choose from various interventions, including trauma-informed guilt reduction therapy.


The bystander effect commonly occurs during urgent, traumatic, or otherwise stressful incidents in which there are multiple witnesses but no one responds to help. Those who have experienced the bystander effect may struggle with feelings of guilt or shame after the situation has ended, believing they could or should have done more to help the targeted individual. Coping with these emotions in a healthy way can be key to moving forward. 

In some cases, the assistance of a licensed online therapist could be beneficial during this process. With BetterHelp, you can be matched with a therapist who has experience helping people recover from a traumatic event. Take the first step toward healing and reach out to BetterHelp today.

Target disruptive behavior in therapy

The information on this page is not intended to be a substitution for diagnosis, treatment, or informed professional advice. You should not take any action or avoid taking any action without consulting with a qualified mental health professional. For more information, please read our terms of use.
Get the support you need from one of our therapistsGet Started