In Tremors in the Blood: Murder, Obsession, and the Birth of the Lie Detector (Crooked Lane, Mar.), Wired reporter Katwala examines the origins of the polygraph.
What inspired this book?
My background is in experimental psychology, and so I’ve always been interested in the brain and neuro-
science. I was watching the series, Making a Murderer, about Steven Avery. One of the things he did to try and clear his name was a new form of lie detection based on brain scans. A little alarm went off in my head—it didn’t make sense to me that that is a viable technology. I went down this big reporting rabbit hole, looking at new forms of lie detection. As I was doing that, I also found out how fascinating the story of the original invention of the polygraph is.
Is there something uniquely American about the use of the polygraph?
One reason the polygraph is so popular in the U.S. is that the American justice system places a high premium on an early confession, partly because the system works through so many more people than justice systems in other countries. More Americans get arrested and get charged, so there’s a premium on a tool that can help the police with the huge caseload.
What do you think the appeal is of having a machine supposedly able to detect lies?
People have always tried to put a framework on the world to help them understand it. Over time, we have replaced appealing to witch trials, or rituals, with a more science-driven direction. I’m not anti-science, but I think there’s a tendency for people to put too much faith in technology before that technology is ready. You see this all the time, not just with lie detection. If you look at the Theranos scandal, it’s a really good example of all these people being suckered by what’s essentially an attractive package housing some existing technology and presented like a new thing. And that’s kind of what the polygraph was, as well, to a certain extent.
Does the way science gets presented contribute to that?
The scientific method is fundamentally the best way we’ve come up with for getting to the truth. Where the problem comes in is where science meets business before it’s ready. Because in an ideal world, you do the science, and you’d make 99.999% sure that this thing worked. And then you would go out and commercialize it. But what happens is, because of commercial imperatives and other pressures, you actually get to like 80%. You stick everything in a pitch deck, and then you go out and you get funding before you’ve really done the due diligence on the device.
