The bystander effect is a theory that explores why people are less likely to help a person in need when there are other people also watching or nearby the event. A horrible attack in 1964 led to the first research on the bystander effect. Many people witnessed the attack and did nothing to help, prompting researchers Bibb Latané and John Darley to posit and develop their theory of help-giving known as the bystander effect.

Three Factors

Research shows that three factors contribute to the bystander effect.

The first is a diffusion of responsibility or the feeling of having less responsibility when other people are present.

The second is evaluation apprehension, which is the fear of being judged by others when offering help.

Pluralistic ignorance is the third factor: when people believe that the situation is not an emergency because no one else is helping.

people walking past a homeless man on the street


Sole Bystander vs. Group Reactions

In Latané and Darley's research, people who were the sole bystander always intervened, but those who were part of a group of five bystanders helped only 62 percent of the time. Various researchers have explored this phenomenon in different situations and consistently arrived at the same results, regardless of whether the event was a serious accident, a non-emergency, an internet incident, or if children were involved.

mass of people crossing a city street


The Brain

Other researchers have searched for explanations for the bystander effect. One study looked at multiple other factors, including the brain activity of bystanders, to determine if non-action is a decision they actively make or a reflex. Study participants witnessed an event alone or with two or four bystanders. MRI scans showed that brain activity increased in the regions responsible for attention and vision during the event but not in those that encourage pro-social behavior.

mri scans of a healthy brain


The Role of Personality

Personality may also play a role in explaining the bystander effect. Early research indicated that personality had no effect and that the apathy needed for the bystander effect is present in everyone. Other studies show that those with a higher degree of sympathy are more likely to help others, whether or not other people are present. Those who feel personal distress from witnessing an emergency are less likely to help when bystanders are present, and this appears to be more of a reflex than a choice.

person extending a helping hand


Fight, Freeze, Flight

The fight, freeze, or flight response may also contribute to the bystander effect. In this case, the thought of helping does not occur to someone witnessing an emergency, but their natural responses for avoidance and survival take over. In time, this reaction slows, and sympathy may override the response, encouraging someone to help. The presence of bystanders seems to make it less likely that sympathy will win. Avoidance of the situation contributes to bystander apathy, but this does not seem to be a conscious choice.

group of angry people with fists raised


Why Group Size Matters

One study speculates that group size matters because people believe that only those best-suited to help should intervene. For example, only a firefighter should attempt to put out a fire. People may assess the situation and think there is nothing they can do and that someone else in the group must be more qualified to help. The bystander effect is reduced when people in the group know one another and know how their skills and capabilities compare to one another.

lots of people walking downtown


Alcohol Consumption and the Bystander Effect

Alcohol consumption alters the bystander effect in interesting ways. Alcohol makes people less inhibited, and studies show that people experience alcohol myopia when drinking, which causes them to be less attentive to obvious things and more attentive to less obvious things. This shift could lead to an increase in willingness to help.

People also use alcohol as an excuse for behavior outside the norm. Studies show that alcohol not only makes people more likely to act in emergencies, but it also makes them act more quickly.

group of friends having drinks by the water


The Bystander Effect and Gender

In some situations, gender plays a role in the bystander effect, specifically when it involves women and sexual assault. One study showed that the more a male bystander drank, the less likely he was to intervene, particularly if he has a sexist history or had committed prior sexually aggressive acts. The combination of their beliefs and alcohol consumption makes it unlikely that they will interpret sexual assault on a woman as something requiring intervention.

woman walking on busy street, people behind her


Be an Active Bystander

Active bystanders are often the only reason an incident stops, but taking on this role is not easy. One effective technique is to act as if you are the only person witnessing the incident. Victims can sometimes encourage people in the crowd to act by making and holding eye contact with someone.

Intervening does not have to be physical. Sometimes it is as easy as shouting that the police are on their way. Active bystanders should direct other bystanders on what to do, as most people will be willing to help if someone else takes control.

man looking out window calling in a crime


Legal Risks

Some people may be hesitant to get involved because they worry about legal implications. Generally, bystanders are not legally compelled to help, but some places have duty-to-rescue laws which require bystanders to act.

In some cases, people are worried they'll be held responsible if their involvement has a negative result. However, many places have Good Samaritan laws that legally protect those whose attempts to help have unexpected results.

young woman calling ambulance for collapsed older woman


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