Sunday, September 4, 2016
Levitin, A Field Guide to Lies
I’m not sure what has prompted the recent spate of courses on and books about critical thinking. Perhaps the explosion in the number of sources of information and misinformation. Perhaps the demand for speed, which usually conflicts with careful thought. Perhaps the crafting of “facts” to match the ideological biases of fractured audiences. The list could go on and on. But a lot of people are believing a lot of crazy things, and this makes academics nervous. Rightly so.
The major shortcoming of the “critical thinking movement,” however, at least as I see it, is that focuses almost exclusively on the structure of reasoning, with a heavy dose of statistics and a smattering of logic. Unfortunately, this formal structure collapses under the weight of ignorance and blind ideological bias. And ignorance and bias are problems that no single book can solve.
That said, Levitin has done a good job, though sometimes with tired examples, of pointing out ways in which our thinking can be led astray. He divides his book into three parts: numerical (mishandled statistics and graphs), verbal (faulty arguments), and the scientific method.
One of the book’s strengths lies in explaining Bayesian statistics to those who do better filling in boxes than solving equations. In fact, throughout the book Levitin shows how not to be fooled by numbers even if one is not really numerate. Take, for instance, the street game with three double-sided cards: one is red on both sides, one white on both sides, and one red on one side and white on the other. “The con man draws one card from the hat and shows you one side of it and it is red. He bets you $5 that the other side is also red.” Should you take the bet? Well, you know the answer is “no.” Even if you think there’s no sleight of hand involved and there is a 50-50 chance that the other side is white, it’s not a good deal. But in reality there’s a two in three chance that the other side is red. “Most of us fail to account for the fact that on the double-red card, he could be showing you either side.”
The more people think critically, the less unintended harm they will probably do. Jurors will probably send fewer innocent people to jail, doctors will probably recommend fewer unnecessary procedures. Unless, of course, contravening biases color their thinking.