In their study of subway bystander behavior, Piliavin et al. (1969) implemented strict control measures by standardizing the appearance and behavior of the victims.
Identify two characteristics of the victims, other than the props they carried, that were kept constant across all trials.
105 exam-style questions on OCR A Level Psychology Responses to people in need, covering Piliavin et al. (1969): Subway Samaritan and Levine et al. (2001): Cross-cultural altruism. Each one has a worked solution and a mark scheme showing where the marks go.