John Darley (b. April 3, 1938) is a distinguished U.S. social psychologist, who has made contributions to the study of helping behaviour. April 3 is the 93rd day of the year (94th in leap years) in the Gregorian calendar, with 272 days remaining. ... 1938 (MCMXXXVIII) was a common year starting on Saturday (link will take you to calendar). ...

He studied at Swarthmore College from 1956-1960, where he obtained his Bachelor's degree (1960), and later attended Harvard University, from which he obtained his Master's degree in 1962 and his Ph.D.in 1965. He is probably best known for his collaboration with Bibb Latane in looking at why people do not always intervene (i.e. offer aid) at the scene of an emergency, a research interest largely stemming from the tragic case of Kitty Genovese, the New Yorker who was murdered in a New York suburb in March 1964 in the presence of 38 witnesses, of whom not one did as much as telephone police services. Experimental research with Bibb Latane persuaded Darley that, other things being equal, more people present at the scene of an emergency could lead to reduced likelihood that any one would help, for two reasons: Swarthmore College is a private liberal arts college in the United States, with an enrollment of about 1450 students. ... Harvard University campus (old map) Harvard University (incorporated as The President and Fellows of Harvard College) is a private university in Cambridge, Massachusetts. ... Bibb Latane (born 1937) is a United States social psychologist. ... Kitty Genovese, picture from the New York Times article Thirty-Eight Who Saw Murder Didnt Call the Police. Catherine Genovese (1935–March 13, 1964), commonly known as Kitty Genovese, was a New York City woman who was stabbed to death near her home in the Kew Gardens section of...

• Pluralistic ignorance, the assumption that because no one is helping, everything must be all right;
• Diffusion of responsibility, a sense of shared responsibility when other are present.

Since 1980, further experiments by social psychologists have suggested important qualifications to this general rule,and identified conditions where increasing bystander number at the scene of an emergency may actually increase likelihood of helping. One of Darley's most distinguished Ph.D. students has been Daniel Batson. C. Daniel Batson (b. ...