Which psychological concept is illustrated through the bystander effect?

The bystander effect is a social psychological phenomenon that occurs when individuals witness an emergency or a crisis but do not offer help, often because they assume that someone else will take responsibility. This leads to the concept of diffusion of responsibility, which explains that in group settings, individuals may feel less personal accountability to intervene, believing that others will act instead. As the number of bystanders increases, the likelihood of any one person helping decreases, because everyone assumes someone else will intervene.

In the context of group dynamics, the bystander effect illustrates how social influences can alter individual behavior in emergencies. People may look to others in the group for cues about how to react, often resulting in inaction due to the belief that someone else will step in. Thus, this phenomenon effectively demonstrates the interplay of group dynamics and the diffusion of responsibility in influencing behavior in critical situations.