Diffusion of Responsibility: Definition and Examples in Psychology

When the Presence of Others Makes Us Less Helpful

Individuals cross a busy city street.

 LeoPatrizi / Getty Images

What causes people to intervene and help others? Psychologists have found that people are sometimes less likely to help out when there are others present, a phenomenon known as the bystander effect. One reason the bystander effect occurs is due to diffusion of responsibility: when others are around who could also help, people may feel less responsible for helping.

Key Takeaways: Diffusion of Responsibility

  • Diffusion of responsibility occurs when people feel less responsibility for taking action in a given situation, because there are other people who could also be responsible for taking action.
  • In a famous study on diffusion of responsibility, people were less likely to help someone having a seizure when they believed there were others present who also could have helped.
  • Diffusion of responsibility is especially likely to happen in relatively ambiguous situations.

Famous Research on Diffusion of Responsibility

In 1968, researchers John Darley and Bibb Latané published a famous study on diffusion of responsibility in emergency situations. In part, their study was conducted to better understand the 1964 murder of Kitty Genovese, which had captured the public’s attention. When Kitty was attacked while walking home from work, The New York Times reported that dozens of people witnessed the attack, but didn’t take action to help Kitty.

While people were shocked that so many people could have witnessed the event without doing something, Darley and Latané suspected that people might actually be less likely to take action when there are others present. According to the researchers, people may feel less of a sense of individual responsibility when other people who could also help are present. They may also assume that someone else has already taken action, especially if they can’t see how others have responded. In fact, one of the people who heard Kitty Genovese being attacked said that she assumed others had already reported what was happening.

In their famous 1968 study, Darley and Latané had research participants engage in a group discussion over an intercom (in actuality, there was only one real participant, and the other speakers in the discussion were actually pre-recorded tapes). Each participant was seated in a separate room, so they couldn’t see the others in the study. One speaker mentioned having a history of seizures and seemed to begin having a seizure during the study session. Crucially, the researchers were interested in seeing whether participants would leave their study room and let the experimenter know that another participant was having a seizure.

In some versions of the study, participants believed that there were only two people in the discussion—themselves and the person having the seizure. In this case, they were very likely to go find help for the other person (85% of them went to go get help while the participant was still having the seizure, and everyone reported it before the experimental session ended). However, when the participants believed that they were in groups of six—that is, when they thought there were four other people who could also report the seizure—they were less likely to get help: only 31% of participants reported the emergency while the seizure was happening, and only 62% reported it by the end of the experiment. In another condition, in which participants were in groups of three, the rate of helping was in between the rates of helping in the two- and six-person groups. In other words, participants were less likely to go get help for someone having a medical emergency when they believed that there were others present who could also go get help for the person.

Diffusion of Responsibility in Everyday Life

We often think about diffusion of responsibility in the context of emergency situations. However, it can occur in everyday situations as well. For example, diffusion of responsibility could explain why you might not put in as much effort on a group project as you would on an individual project (because your classmates are also responsible for doing the work). It can also explain why sharing chores with roommates can be difficult: you might be tempted to just leave those dishes in the sink, especially if you can’t remember whether you were the person who last used them. In other words, diffusion of responsibility isn’t just something that occurs in emergencies: it occurs in our daily lives as well.

Why We Don’t Help

In emergencies, why would we be less likely to help if there are others present? One reason is that emergency situations are sometimes ambiguous. If we aren’t sure whether there’s actually an emergency (especially if the other people present seem unconcerned about what is happening), we might be concerned about the potential embarrassment from causing a “false alarm” if it turns out that there was no actual emergency.

We may also fail to intervene if it’s not clear how we can help. For example, Kevin Cook, who has written about some of the misconceptions surrounding Kitty Genovese’s murder, points out that there wasn’t a centralized 911 system that people could call to report emergencies in 1964. In other words, people may want to help—but they may not be sure whether they should or how their help can be most effective. In fact, in the famous study by Darley and Latané, the researchers reported that the participants who didn’t help appeared nervous, suggesting that they felt conflicted about how to respond to the situation. In situations like these, being unsure of how to react—combined with the lower sense of personal responsibility—can lead to inaction.

Does the Bystander Effect Always Occur?

In a 2011 meta-analysis (a study that combines the results of previous research projects), Peter Fischer and colleagues sought to determine how strong the bystander effect is, and under which conditions it occurs. When they combined the results of previous research studies (totaling over 7,000 participants), they found evidence for the bystander effect. On average, the presence of bystanders reduced the likelihood that the participant would intervene to help, and the bystander effect was even greater when there are more people present to witness a particular event.

However, importantly, they found that there may actually be some context where the presence of others doesn’t make us less likely to help. In particular, when intervening in a situation was especially likely to be dangerous for the helper, the bystander effect was reduced (and in some cases, even reversed). The researchers suggest that, in particularly dangerous situations, people may see other bystanders as a potential source of support. For example, if helping in an emergency situation could threaten your physical safety (e.g. helping someone who is being attacked), you’re probably likely to consider whether the other bystanders can help you in your efforts. In other words, while the presence of others usually leads to less helping, this isn’t necessarily always the case.

How We Can Increase Helping

In the years since initial research on the bystander effect and diffusion of responsibility, people have looked for ways to increase helping. Rosemary Sword and Philip Zimbardo wrote that one way of doing this is to give people individual responsibilities in an emergency situation: if you need help or see someone else who does, assign specific tasks to each bystander (e.g. single out one person and have them call 911, and single out another person and ask them to provide first aid). Because the bystander effect occurs when people feel a diffusion of responsibility and are unsure of how to react, one way to increase helping is to make it clear how people can help.

Sources and Additional Reading:

  • Darley, John M., and Bibb Latané. "Bystander Intervention in Emergencies: Diffusion of Responsibility." Journal of Personality and Social Psychology 8.4 (1968): 377-383. https://psycnet.apa.org/record/1968-08862-001
  • Fischer, Peter, et al. "The bystander-effect: A meta-analytic review on bystander intervention in dangerous and non-dangerous emergencies." Psychological Bulletin 137.4 (2011): 517-537. https://psycnet.apa.org/record/2011-08829-001
  • Gilovich, Thomas, Dacher Keltner, and Richard E. Nisbett. Social Psychology. 1st edition, W.W. Norton & Company, 2006.
  • Latané, Bibb, and John M. Darley. "Group inhibition of bystander intervention in emergencies." Journal of Personality and Social Psychology 10.3 (1968): 215-221. https://psycnet.apa.org/record/1969-03938-001
  • “What Really Happened The Night Kitty Genovese Was Murdered?” NPR: All Things Considered (2014, Mar. 3). https://www.npr.org/2014/03/03/284002294/what-really-happened-the-night-kitty-genovese-was-murdered
  • Sword, Rosemary K.M. and Philip Zimbardo. “The Bystander Effect.” Psychology Today (2015, Feb. 27). https://www.psychologytoday.com/us/blog/the-time-cure/201502/the-bystander-effect