Talking to Strangers - Malcolm Gladwell Page 0,123
less accurate in their judgments of truth and deception. Yet they were more self-confident and more articulate about the reasons for their often erroneous judgments.
“I apologize…these last couple of weeks…”: “Sandy Speaks—March 1, 2015,” YouTube, posted July 24, 2015, youtube/watch?v=WJw3_cvrcwE, accessed March 22, 2019.
DOJ report on Ferguson, Missouri: United States Department of Justice Civil Rights Division, “Investigation of the Ferguson Police Department,” March 4, 2015, justice.gov/sites/default/files/opa/press-releases/attachments/2015/03/04/ferguson_police_department_report.pdf.
African Americans are considerably more likely to be subjected to traffic stops (in footnote): Charles R. Epp, Steven Maynard-Moody, and Donald Haider-Markel, How Police Stops Define Race and Citizenship (Chicago: University of Chicago Press, 2004).
North Carolina State Highway Patrol statistics: “Open Data Policing: North Carolina,” accessed March 2019, opendatapolicing/nc/, accessed March 2019.
FM 1098 is not “a high-crime, high-drug area”: This crime map reflects Waller County data from 2013 to 2017 collected by Baltimore-based crime data aggregator SpotCrime, which sources data from local police departments.
More on the dilemmas caused by haystack searches: Middle-aged women, in most countries, are encouraged to get regular mammograms. But breast cancer is really rare. Just under 0.5 percent of women who get a mammogram actually have the disease. Looking for breast cancer is therefore a haystack search.
Epidemiologist Joann Elmore recently calculated just what this means. Imagine, she said, that a group of radiologists gave a mammogram to 100,000 women. Statistically, there should be 480 cancers in that 100,000. How many will the radiologists find? 398. Believe me, for a task as difficult as reading a mammogram, that’s pretty good.
But in the course of making those correct diagnoses, the radiologists will also run up 8,957 false positives. That’s how haystack searches work: if you want to find that rare gun in someone’s luggage, you’re going to end up flagging lots of hair dryers.
Now suppose you want to do a better job of spotting cancers. Maybe getting 398 out of 480 cases isn’t good enough. Elmore did a second calculation, this time using a group of radiologists with an extra level of elite training. These physicians were very alert, and very suspicious—the medical equivalent of Brian Encinia. They correctly identified 422 of the 480 cases—much better! But how many false positives did that extra suspicion yield? 10,947. An extra two thousand perfectly healthy women were flagged for a disease they didn’t have, and potentially exposed to treatment they didn’t need. The highly trained radiologists were better at finding tumors not because they were more accurate. They were better because they were more suspicious. They saw cancer everywhere.
If you are a woman, which group of radiologists would you rather have read your mammogram? Are you more concerned about the tiny chance that you’ll have a cancer that will be missed, or the much larger probability that you’ll be diagnosed with a cancer you don’t have? There’s no right or wrong answer to that question. Different people have different attitudes toward their own health, and toward risk. What’s crucial, though, is the lesson those numbers teach us about haystack searches. Looking for something rare comes with a price.
The author is grateful for permission to use the following ed material:
Photos: Duchenne and non-Duchenne smiles. Reprinted by permission of Paul Ekman, Ph.D./ Paul Ekman Group, LLC.
Photo: “Anger” from Job van der Schalk et al., “Moving Faces, Looking Places: Validation of the Amsterdam Dynamic Facial Expression Set (ADFES),” Emotion 11, no. 4 (2011): 912. Reproduced by permission of author.
Images: “Rey-Osterrieth Complex Figure,” “Sample ROCF immediate recall drawings from the Pre/Post-stress groups,” “Sample ROCF immediate recall drawings from the Stress Group,” from Charles A. Morgan et al., “Stress-Induced Deficits in Working Memory and Visuo-Constructive Abilities in Special Operations Soldiers,” Biological Psychiatry 60, no. 7 (2006): 722–29. Reproduced by permission of Dr. Charles A. Morgan III and Elsevier.
Excerpt from “The Addict,” by Anne Sexton from Live or Die (Boston: Houghton Mifflin, 1966). Reprinted by permission of SLL/Sterling Lord Literistic, Inc. by Anne Sexton.
Graphs: “Relation between gas suicides in England and Wales and CO content of domestic gas, 1960–77”; “Crude suicide rates (per 1 million population) for England and Wales and the United States, 1900–84”; “Suicides in England and Wales by domestic gas and other methods for females twenty-five to forty-four years old” from Ronald V. Clarke and Pat Mayhew, “The British Gas Suicide Story and Its Criminological Implications,” Crime and Justice 10 (1988): 79–116. Reproduced by permission of Ronald V. Clarke, Pat Mayhew, and the University of Chicago Press.
Map: Weisburd Jersey city map from David Weisburd, et al., “Does Crime Just Move Around The Corner? A Controlled Study of Spatial Displacement and Diffusion of Crime Control Benefits,” Criminology 44, no. 3 (2006): 549–91. Reproduced by permission of David Weisburd and the American Society of Criminology.