What Would You Do? Investigating the ‘Bystander Effect’

In March 1964, a bar manager named Kitty Genovese was stabbed to death in the Kew Gardens district of New York City. Thirty-eight residents from a nearby apartment complex witnessed and reported her murder, yet no one intervened. Initially, many wondered: Why did no one help? Are humans cold and uncaring, or was something else going on?

The Genovese murder prompted many questions for law enforcement as well as psychologists, and Genovese’s unfortunate demise has prompted years of debate over a psychosocial phenomenon that appears real: the bystander effect.

Standing by . . . And Doing Nothing

If you were to witness someone being murdered, would you intervene?

When asked this question, many people would probably respond “yes.” Decades of research into this question has produced a somewhat shocking and unexpected answer. You would intervene—sure—but if the crime was taking place in front of a group or crowd, the likelihood of you intervening diminishes considerably. In other words, as put by Christian Jarrett, a writer of popular psychology, “The more people present in a given situation, the less likely we are to intervene when someone is in need of help.”

The first to investigate the bystander effect after the Genovese murder were John Darley and Bibb Latane. The researchers became intrigued by the Genovese case, and in 1968, Darley and Latane conducted a well-known experiment in the history of psychology, the seizure experiment. In it, the psychologists asked a group of university students to engage in discussion in separate rooms, whereby they could only communicate through using microphones and headphones. One “person,” who was actually a pre-recorded voice, began to have a seizure and soon after stopped talking. The other participants, who, again, were actually pre-recorded voices and were not actual participants, failed, in most cases, to see if the man having the seizure was alright.

Again, the key idea here is that, although only one person was participating in the experiment, he or she believed that they were talking amongst a group. As summarized by Adam Hart-Davis, “Almost all of the participants were convinced that the fit was real. Of those that thought they were the only person to have heard the attack, 100 percent reported the fit, with 85 percent running to the corridor before the ‘victim’ had stopped speaking.”

Similar experiments have verified an important point, as noted by Hart-Davis: “. . . not only were people in groups less likely to respond to an emergency than individuals, but the response was inversely proportional to the number of witnesses.” In other words, “The greater number of bystanders, the less likely it was that anyone would help.”

Support and Criticisms

Although the bystander effect has been well-documented throughout the psychological literature, it has not been without its critics. Joseph de May, a historian, “. . . analyzed proceedings from the trial of Winston Mosely—Kitty Genovese’s murder—[and] he found [that] the story that 38 witnesses did nothing was little more than a myth based on inaccurate newspaper reporting.” Yet, despite May’s best efforts to explain away the bystander effect, it has—over the decades—been accepted as a legitimate psychosocial phenomenon.

Along with Stanly Milgram’s Obedience to Authority experiments and Philip Zimbardo’s Stanford Prison Experiment, the bystander effect emerged at a time when major progress was being made in the area of social psychology.

Indeed, in the 1960s and 1970s, psychologists began to probe group dynamics in a way that had not been done before. Most importantly, too, remains that though more investigation of the bystander effect, it has been known—especially in the case of the seizure experiment—that most individuals are not uncaring and cold. Rather, most people may simply feel less responsibility to act when in the presence of others. Finally, if anything, the bystander effect illustrates how individual preference and will becomes subordinate while in the midst of the crowd.


Hart-Davis, A. (2015). Pavlov’s Dog: Groundbreaking experiment psychology. London: Metro Books.

Jarrett, C. (2011). 30-second psychology: The 50 most thought-provoking psychology theories, each explained in half a minute. Sydney: Murdoch Books.

Brooke Lamberti

Brooke Lamberti is a content writer based out of Scranton, Pennsylvania. She received a Bachelor of Science in Psychology from Marywood University, and has prior career experience working in social work and domestic violence advocacy. She has a passion for writing and helping others.

Leave a Comment