In 1968 the psychologists John Darley and Bibb Latané published a study on whether people help someone who is having a seizure. When participants believed they were alone, 85 percent went for help before the seizure ended. When they believed one other person was present, 62 percent did. With four other bystanders, only 31 percent did. The authors called the effect diffusion of responsibility.
The research was prompted by the murder of Kitty Genovese in Queens on March 13, 1964. A New York Times story reported that dozens of neighbors saw the attack and did not call the police. Later reprints of the headline gave the number as 38.
That story was wrong. A 2007 article in American Psychologist found no evidence of 38 witnesses. In 2016 the Times itself called its story “flawed.”