However, further research revealed nuances in this understanding. Rachel Manning and her colleagues found that the original story of Kitty Genovese’s crime was not as clear-cut as reported; some people had called the police and others had shouted from their windows.
Peter Fisher’s meta-analysis also supported the bystander effect but indicated that the presence of passive bystanders specifically reduced helping responses. Interestingly, when one person was instructed to help, the effect reversed: people became more likely to help, suggesting that the primary explanation for the bystander effect might be uncertainty rather than diffusion of responsibility.