You may not remember her; I do, both because her 1964 murder outside her apartment block had a profound effect on psychology and because, at the time, I was a 12-year old living less than a mile from where it happened. The story has it that her murder was witnessed by 38 neighbors, none of whom called the police, supposedly because each thought another would do so. It is the basis for the well-known psychological principle of the ‘bystander effect’ in which individual responsibility is diffused by experiencing an event as part of a crowd. Now, Mind Hacks describes a revisionist history of what really happened.