What is the bystander effect? How to safely intervene when you see someone in need of help

If you saw someone being harassed or assaulted in a busy public place, what would you do?

Psychologists have long explored that question with the bystander effect, "a phenomenon in which people fail to offer needed help in emergencies, especially when other people are present in the same setting," according to the American Psychological Association. It sounds unimaginable to doing nothing when someone is suffering, but the theory may explain how the assault of an Asian woman in New York City could have unfolded without intervention by two prominent witnesses.

This week, two doormen who worked at an apartment building were fired for disregarding emergency protocols as Vilma Kari, 65, a Filipino-American woman who was walking to church was punched and kicked to the ground by a man named Brandon Elliot who yelled anti-Asian statements. Apartment building security cameras captured not only the unprovoked attack that left Kari hospitalized but also the nonresponse of employees who instead closed the entrance door and did not call 911 (a union that represents the workers alleges that because Elliott had a knife, the employees waited until he fled before flagging down a cop car). The incident ignited outrage and Mayor Bill de Blasio called the workers' actions "absolutely unacceptable," urging the "crucial" need for interventional bystander training.

The bystander effect was first studied in 1968 by psychologists Bibb Latané and John Darley, four years after the 1964 murder case of Catherine “Kitty” Genovese, 28, a bar manager who was stabbed to death by a stranger in her Queens, N.Y. neighborhood, in the early morning hours. According to a 1964 New York Times article titled "37 Who Saw Murder Didn't Call the Police; Apathy at Stabbing of Queens Woman Shocks Inspector," neighbors did little as Genovese screamed for help, save for opening windows and turning on lights, although one man shouted, "Let that girl alone!" Thirty minutes passed before a neighbor called the police, only after much deliberation. "I didn't want to get involved," he said. Other neighbors misinterpreted what they heard ("We thought it was a lover's quarrel," said one) or were "tired." Later, details of the case were questioned (even by the New York Times), such as the number of bystanders and their comprehension of the attack.

Latané and Darley determined that people (regardless of personality type) are likelier to help others when they're the sole witness versus one in a group. People aren’t insensitive to victims, they argued in their landmark study, but personal responsibility diminishes in a crowd, along with fear of being personally blamed for inaction. "A person witnessing an emergency situation, particularly such a frightening and dangerous one as a stabbing, is in conflict," they wrote. "There are obvious humanitarian norms about helping the victim, but there are also rational and irrational fears about what might happen to a person who does intervene" such as potential physical harm to oneself, public embarrassment and police interaction. In the case of Genovese, they theorized, bystanders concealed in their own apartments, could have assumed that help was on the way.

However, newer research challenges the bystander effect. Last year, a team led by Richard Philpot, a research fellow at Lancaster University, analyzed 219 real-life altercations caught on CCTV cameras in the United Kingdom, the Netherlands and South Africa and found that in 90 percent of situations, at least one witness intervened, by either making peaceful gestures, consoling victims or physically stopping aggressors. "Finally, we find that increased bystander presence is related to a greater likelihood that someone will intervene," wrote the study authors. "Taken together these findings allay the widespread fear that bystanders rarely intervene to help. We argue that it is time for psychology to change the narrative away from an absence of help and toward a new understanding of what makes intervention successful or unsuccessful."

The anti-harassment movement Hollaback! and the nonprofit organization Alteristic, are trying with the "5 Ds of Bystander Intervention," a five-step approach to helping crime victims. "We often see emergencies through our own lens, personality traits or cultural norms," Kristen Parks, vice-president of programs at Alteristic, tells Yahoo Life. "And research shows us that bias based on race, gender and sexuality also affects how individuals respond to perceived risks." For example, a bystander might worry about perpetuating negative stereotypes by intervening with perceived aggressive behavior or someone who hates conflict could freeze up and fail to act.

Parks adds, "Most people would say 'absolutely' when asked if they would intervene in a [hypothetical] situation where a woman was assaulted in a park. But in order to learn realistic and safe intervention methods, we have to discuss what makes it so hard."

Emily May, the co-founder and executive director of Hollaback!, tells Yahoo Life that personal safety should be prioritized when executing the 5 Ds, which represent distract, delegate, document, delay and direct, in no particular order.

In the first, bystanders create a distraction to stop the aggressor. "You can drop something, scream loudly or start a casual conversation with the victim if the harassment is verbal," she says. One witness to Kari’s attack tried that, according to daughter Elizabeth Kari’s GoFundMe page for her mother's medical expenses. "There were many times that I wish someone would have stepped in," she wrote. "However, what this video did not capture was that there was someone who was standing across the street that witnessed my mom getting attacked who yelled and screamed to get the assailant’s attention…to this person, I understand your decision in remaining anonymous during this time. I want to THANK YOU for stepping in and doing the right thing."

A bystander could also delegate by finding help. "You could call the police, but [depending on the circumstance] we recommend checking in with the victim since communities of color may not feel safer with police presence," says May. "You could also say to another witness, 'Hey, do you see what’s going on here?' so everyone is aware of what's happening."

From a safe distance, document the incident on your cell phone and give the footage to the victim, without posting it online or utilizing it without permission. Hollaback! recommends capturing any geographical information such as street signs that would identify the scene.

Bystanders can "delay" their response by hanging around the scene to comfort the victim. "Even if you can’t act in the moment, you can make a difference for the person who has been harassed by checking in on them after the fact," according to the organization, especially if the incident happened in passing or very quickly." One finding from a Hollaback! survey conducted with the Worker Institute at Cornell University found that even a knowing look made a positive influence on the victim. Or, offer to accompany him or her to a destination or help file a police report.

If it feels safe to do so, bystanders can "direct," by drawing a boundary. "Saying, 'Don't hurt her' or 'Step away,' without getting into a back-and-forth with the harasser," says May. "Then, turn your attention to the victim and prioritize their care."

Read more from Yahoo Life:

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• Jazz Jennings recalls being 'devastated' by transgender soccer ban at age 8

• Lena Dunham on body positivity: 'We want curvy bodies that look like Kim Kardashian has been up-sized slightly

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