What Is Diffusion of Responsibility?

Why being part of a group diminishes individual sense of resposibility

What is diffusion of responsibility
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Diffusion of responsibility is a psychological phenomenon in which people are less likely to take action or feel a sense of responsibility in the presence of a large group of people. Essentially, in a large group of people, people may feel that individual responsibility to intervene is lessened because it is shared by all of the onlookers.

Diffusion of responsibility is often used to explain the bystander effect, a phenomenon in which the greater the number of people present, the less likely people are to help an individual in distress.

For example, imagine that you are in a large city on a bustling street. You notice a young man fall to the ground and start convulsing as if having a seizure. Many people turn and look at the man, but no one moves to help or call for medical assistance. Why? Because there are so many people present, no one individual feels pressured to respond. Each person might think, "Oh, someone else has probably already called for help" or "No one else is doing anything, so it must not be that serious."

Kitty Genovese: A Classic Example of Diffusion of Responsibility

The brutal murder of a woman named Kitty Genovese is often cited as a classic example of diffusion of responsibility. According to the original story related by The New York Times, 38 people watched her attack yet failed to call the authorities for help. Later research has shown that few of the neighbors in the area actually had a clear view of what was happening, yet it is clear that at least a few of the onlookers were aware that a woman was being attacked on the street.

Those who did hear her screams dismissed it as a "lover's quarrel" or suggested that they simply did not want to get involved.

So why is it that people are so often able to come up with such excuses to not get involved? In an article for Psychology Today, Dr. Alex Lickerman suggests that that this tendency to explain away what is happening represents a form of narrative rationalization.

"Knowing that others heard the same scream, or received the same email request, or came upon a man down powerfully tempts us to assume someone else has taken responsibility for doing what needs to be done," he explains.

While such failure to take action is often viewed as apathy or even plain cold-heartedness, researchers have been able to consistently demonstrate that such inaction is most often due simply to the presence of other people.

Research on Diffusion of Responsibility

In a series of classic experiments conducted in the late 1960s, researchers John Darley and Bibb Latané asked participants to fill out questionnaires in a room which suddenly began to fill with smoke. In some conditions the subjects were alone, in a second condition there were three naive subjects in the room, and in a third condition there was one subject and two confederates who intentionally ignored the smoke.

In situations where the subject was alone, approximately 75 percent reported the smoke to the experimenters. In the condition where the two confederates ignored the smoke, on 10 percent of the naive subjects told the experimenters about the smoke.

In one fascinating series of experiments, researchers Garcia and his colleagues found that simply imagining being part of a crowd made people less likely to help.

The researchers ask participants to imagine being part of a crowd and then placed the participants in a situation where they had the chance to help another person. What the researchers discovered that those who had simply imagined being part of a larger group were less likely to help than those who had imagined themselves being alone.

Darley and Latané noted that once a person notices that something is happening, a series of important decisions must first be made.

  1. The first step involves actually noticing a problem.
  2. Next, the individual must decide if what they are witnessing is actually an emergency.
  1. Next is perhaps the most critical decision in this process - deciding to take personal responsibility to act.
  2. Then the individual has to decide what needs to be done.
  3. Finally, the bystander must actually take action.

What complicates this process is that these decisions often need to be made quickly. There is often an element of danger, stress, emergency, and sometimes personal risk involved. Adding to this pressure-packed situation is the problem of ambiguity – sometimes it isn't entirely clear who is in trouble, what is wrong, or what needs to be done.

Factors That Influence Diffusion of Responsibility

Researchers have also discovered a number of different factors that can exacerbate or diminish diffusion of responsibility.

Factors that can increase diffusion of responsibility include:

  • Anonymity: Bystanders who do not know the victim are less likely to help and more likely to expect someone else in the crowd to step up and offer assistance.
  • Ambiguous situations: If onlookers are not really sure what is happening, are unclear about who is in trouble, or are unsure if the person really needs assistance, then they are far less likely to take action.

Factors that can decrease diffusion of responsibility include:

  • Knowing the victim: People are more likely to help if they feel some sort of connection or personal knowledge of the person in trouble.
  • Calling on a specific individual for help: Decreasing the psychological distance between the victim and the onlooker. If the victim makes eye contact and asks a specific individual for help, that person will feel more compelled to take action.
  • Having the skills to help: People often fail to assist because they feel unqualified to help. A person who has received specific training in life-saving, first aid, and CPR will probably feel more capable of stepping up and offering assistance.

Learn more about:


Darley, J. M. & Latané, B. (1968). Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology 8: 377–383. doi:10.1037/h0025589.

Garcia, S. M., Weaver, K., Moskowitz, G. B., & Darley, J. M. (2002). Crowded minds: The implicit bystander effect. Journal of Personality and Social Psychology, 83(4), 843-853.

Kassin, S., Fain, S. & Markus, H. R. (2014). Social Psychology. Belmont, CA: Wadsworth.

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