Bystander Effect
What is the Bystander Effect?
The bystander effect is a psychological phenomenon where individuals are less likely to offer help to a victim when other people are present. The greater the number of bystanders, the less likely it is that people will intervene.
The Basic Idea
It’s a bright afternoon in a bustling city. At one of the busiest intersections, a man suddenly collapses on the sidewalk. All around him, commuters hurry to work, tourists take selfies, and street vendors sell newspapers and snacks.
As the man lies there, struggling to breathe, people glance at him, concerned. Some slow their pace, watching to see what others will do, yet no one steps forward. After all, in a crowd this large, someone must have already called for an ambulance, right? Maybe it’s not as serious as it looks, and he just needs to sit down. Maybe someone else, someone more qualified, will get involved.
Several minutes pass, yet no one steps forward to assist. Surrounded by so many others, the sense of personal responsibility to help seems to quietly diminish. Eventually, someone finally realizes help isn’t on the way and they intervene.
While we think we would immediately react in such a situation, the bystander effect suggests that most of us will either hesitate before helping or not assist at all. So why does this happen?
Why Does the Bystander Effect Occur?
The bystander effect is attributed to three main factors: diffusion of responsibility, social influence, and pluralistic ignorance.1
Diffusion of responsibility occurs when the presence of many witnesses causes each individual to feel less personally obligated to intervene. When people are part of a group, they often assume that someone else will step in to help, relieving them of personal responsibility (as we saw in the scenario above). The more bystanders there are, the more diluted each person’s sense of duty becomes. As a result, individuals may hesitate or choose not to act at all.
Social influence, on the other hand, refers to people looking to others’ reactions to decide how they themselves should respond.2 In uncertain situations, especially emergencies that are confusing or ambiguous, individuals often take their cues from those around them. If other bystanders appear calm, indifferent, or passive, people are likely to interpret the situation as non-urgent, even if they initially sensed that something was wrong. This is very similar to conformity, when we adapt our behaviors to match those of the people around us.
Finally, pluralistic ignorance is the belief that if other people aren’t reacting, it obviously isn’t an emergency. Pluralistic ignorance occurs when everyone in a group privately feels uncertain or concerned, but because no one visibly expresses those feelings, each person assumes that others see no cause for alarm. This leads to a situation where everyone is misled by the apparent calm or indifference of those around them.3
“If there’s a lot of people around during an incident, you may feel that you don’t have to take a risk [...] So you don’t have to jump into the swirling river or run into the burning building”
— Frank Farley, professor of psychology at Temple University5
About the Author
Dr. Lauren Braithwaite
Dr. Lauren Braithwaite is a Social and Behaviour Change Design and Partnerships consultant working in the international development sector. Lauren has worked with education programmes in Afghanistan, Australia, Mexico, and Rwanda, and from 2017–2019 she was Artistic Director of the Afghan Women’s Orchestra. Lauren earned her PhD in Education and MSc in Musicology from the University of Oxford, and her BA in Music from the University of Cambridge. When she’s not putting pen to paper, Lauren enjoys running marathons and spending time with her two dogs.
