Talking to Strangers: What We Should Know About the People We Don’t Know

by Malcolm Gladwell

One of Weisburd’s former students, Barak Ariel, went so far as to test resistance to the coupling idea in the Derry region of Northern Ireland. Law-enforcement officers in Derry are asked to identify specific troubled areas of their beats that they think are going to require additional police presence. Their predictions are called “waymarkers.” Ariel wondered: how closely do the police officers’ waymarkers match up with the hot spots where crime actually happens in Derry? I think you can guess. “The majority of streets included in ‘Waymarkers’ were neither ‘hot’ nor ‘harmful,’ resulting in a false positive rate of over 97 percent,” Ariel concluded. This means that 97 percent of the blocks identified by police officers as being dangerous and violent were not dangerous and violent at all. The officers who drew these waymarkers were not sitting behind a desk, remote from the direct experience of the streets. This was their turf. These were crimes they investigated and criminals they arrested. Yet somehow they could not see a fundamental pattern in the location of the strangers they were arresting.