Traffic has been sluggish this week. I wonder if the blog is depressing people….I know it’s been depressing me.
1. A confirmation bias classic. I decided to watch the new Netflix documentary about the hunt for “the Yorkshire Ripper,” Peter Sutcliffe, only because Grace and I had been on a Jack the Ripper binge of late, including the well-done (but completely fictional) Johnny Depp film, “From Hell.” I did not expect “The Ripper” to tell one of most instructive tales of how bias makes you stupid as well illustrating as the perils of confirmation bias, but that’s what it does.
Sutcliffe, a Yorkshire truck driver, murdered 13 women and attacked nine others, but police missed him for five years because they convinced themselves that he only killed prostitutes. This, in turn, led the newspapers to name him after Jack the Ripper, the mysterious serial killer in Victorian London who killed and mutilated five prostitutes in 1888. The name, in turn, reinforced the bias that a Jack copycat was whom they were seeking. As a result, women who were not prostitutes and had been attacked by Sutcliffe were ignored when they went to the police.
With their investigation foundering, police officials decided that letters from someone claiming to be the Ripper were genuine—Jack the Ripper also wrote letters to the police, you see—and a tape recording referring to the letters must have had the real killer’s voice on it. So they had a speech expert identify the accent of the speaker, which placed him in a very small area in Yorkshire. Any suspect who didn’t have that accent was eliminated….including Sutcliffe, who was interviewed nine times. By the end of his rampage, Sutcliffe wasn’t killing prostitutes any more.
Sutcliffe was eventually captured by accident. Says one of those interviewed for the project: “No wonder the police couldn’t catch him. They were chasing a mythic Victorian maniac instead of a real man.”