In sociology, at the end of the 1960s, the so-called "bystander effect" was intensively studied. The central idea of this phenomenon is that the number of participants in a crisis situation affect how quickly (or if at all) any of them will react and contribute to its resolution. To study it experimentally, John M. Darley and Bibb Latané designed an experiment in 1968, placing a volunteer in a room, from which he could communicate with a person located in another room (in fact, this person was a member of the experimenter's team). If necessary, the volunteer could also connect with the head of the experiment. During the interview, which was about an unrelated topic, the experimenter began to pretend that he was having a seizure and needed immediate medical attention. Subsequently, the leaders of the experiment observed the behaviour of the volunteer. The results showed that if a person in need is in contact with a single volunteer, this volunteer reacts almost immediately and tries to help (talks to him, contacts the head of the experiment, and asks him for help). If the circle of volunteers is wider (3-5 people are involved in the conversation), their reaction time increases significantly, as if everyone is hesitating and hope that someone else will react. By comparing the control setting (one volunteer) with the main experiment (multiple volunteers), it is possible to conclude that the presence of several participants in a crisis really complicates their ability to act. Afterwards, the psychological and sociological causes of this phenomenon were investigated in other experiments, but to a certain extent the bystander effect can be observed in everyday life as well (Figure 2.2).