The Bystander Effect

Discussions of bullying and aggression often raise an important question: Why don’t witnesses step in to help? Social psychologists John Latané and Bibb Darley (1968) proposed an explanation known as the bystander effect.

the bystander effect

The bystander effect occurs when individuals are less likely to offer help to a person in distress when other people are present.

Origins of Bystander Research: The Kitty Genovese Case

Interest in the bystander effect intensified after the 1964 murder of Kitty Genovese in New York City. Early news reports—most notably a New York Times article—claimed that 38 witnesses observed the attack and failed to intervene. This story became a powerful symbol of public apathy and motivated decades of research on helping behavior.

A More Accurate Understanding

Later investigations revealed that the original reporting was seriously flawed. Researchers found no evidence that 38 witnesses passively observed the murder, and police records showed that some people did attempt to call for help (Manning, Levine, & Collins, 2007). In 2016, The New York Times acknowledged that its original account had exaggerated both the number of witnesses and their inaction.^[1] In 2016, the Times called its own reporting “flawed”, stating that the original story “grossly exaggerated the number of witnesses and what they had perceived.”^[2]

Although the details of this case were misrepresented, the psychological questions it raised remain important: When do people help—and when do they hesitate?

Despite the inaccuracies of this specific case, the bystander effect phenomenon remains pertinent and can be seen in many instances since that time, such as the 2009 Richmond High School multiple perpetrator rape, the 2010 case of Hugo Alfredo Tale-Yax, or examples found during the 2021 rash of assaults of Asian- Americans. In all of these examples, multiple parties witnessed the assault of another person without stepping in to help and, in some cases, even stopping to film the incident without further intervention.

Helping is More Common Than We Think

Unfortunately, though failures to come to the aid of someone in need are not rare, recent studies reveal that a majority of the time, people do intervene.

In 2019, cultural anthropologist Marie Rosenkrantz Lindegaard led a large international study analyzing 219 street disputes and confrontations recorded by security cameras in three cities in different countries — Lancaster, England; Amsterdam, Netherlands; and Cape Town, South Africa. Contrary to bystander theory, Lindegaard’s team found that bystanders intervened in almost every case, and the chance of intervention went up with the number of bystanders, which she called “a highly radical discovery and a completely different outcome than theory predicts.”

This study is the first large-scale test of the bystander effect in real-life. Up until now, this effect was mainly studied in the lab by asking study subjects how they would respond in a particular situation. Another striking aspect of this study is that the observations come from three different countries including South Africa where, with high rates of violent crime, intervening in a street dispute is not without risk. ‘That appears to indicate that this is a universal phenomenon’, says Lindegaard.^[3]

Despite this, we know that help does not always come for those who may need it the most. Trying to understand why people do not always help became the focus of bystander intervention research (e.g., Latané & Darley, 1970).

Why Don’t People Always Help?

Latané and Darley (1970) proposed that helping involves a series of decisions, not a single choice. At each step, social factors can block intervention.

Step 1: Defining the Situation

pluralistic ignorance

In ambiguous situations, people often look to others to decide whether help is needed. But when everyone is doing this at the same time, no one acts.

Pluralistic ignorance occurs when individuals mistakenly assume that others’ inaction means help is not needed, even when it is.

This process is especially common in:

• bullying situations,
• public harassment,
• online group spaces, and
• emergencies where cues are unclear.

Step 2: Taking Responsibility

When others are present, individuals may feel less personal responsibility to act, assuming someone else will intervene.

diffusion of responsibility

Diffusion of responsibility refers to the tendency for people to be less likely to help when others are also able to help (Darley & Latané, 1968).

Importantly, roles and training can override this effect. For example, first responders, teachers, coaches, and event staff are more likely to act because helping is part of their defined role. This helps explain why trained officials quickly intervened during emergencies such as the 2013 Boston Marathon bombing.

Step 3: Weighing the Costs and Benefits

Even when people recognize an emergency and feel responsible, they still consider the costs and rewards of helping.

Potential costs include:

• physical danger,
• embarrassment,
• legal consequences,
• time or emotional strain.

Potential rewards include:

• gratitude or praise,
• social approval,
• avoiding guilt,
• alignment with personal values.

Helping is more likely when perceived rewards outweigh perceived costs (Dovidio et al., 2006).

Helping Behavior: Egoism or Altruism?

Psychologists continue to debate whether helping behavior is driven primarily by:

• egoism (helping to benefit oneself), or
• altruism (helping purely to benefit others).

In reality, most helping likely involves both. Even professions centered on helping—such as healthcare, teaching, or emergency services—combine concern for others with personal meaning, identity, or social reward.

The Bystander Effect in the Digital Age

Modern bystander situations increasingly occur online. In cases of cyberbullying or viral harassment:

• responsibility feels diffused across thousands of viewers,
• harm may seem less immediate,
• people may assume “someone else will report it.”

Ironically, bystanders sometimes record or share harm rather than intervene. This digital diffusion of responsibility highlights why bystander education now emphasizes active intervention, such as reporting, offering support to victims, or disrupting harmful behavior.

The next time you see someone in need—online or in person—pause and consider:

• Is the situation ambiguous?
• Am I assuming someone else will help?
• What small action could I take?

Even low-cost actions—checking in, reporting, calling for help—can disrupt the bystander effect and make a meaningful difference.

What do you think is the primary motive for helping behavior: egoism or altruism? Are there any professions in which people are being “pure” altruists, or are some egoistic motivations always playing a role?

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