My most examined post What Has Brunswik’s Lens Model Taught? was based on a paper authored by Karelaia and Hogarth. It only seems right to look at some of Karelaia’s other work. This post is based on a working paper from INSEAD, “Improving Decision Making through Mindfulness,” authored by Natalia Karelaia and Jochen Reb, forthcoming in Mindfulness in Organizations, Reb, J., & Atkins, P. (Eds.), Cambridge University Press.
This paper is a review of the literature surrounding the premise that even when it comes to making decisions, an activity that is often quite conscious, deliberate and intentional, people are typically not as aware as they could be. Karelaia and Reb argue that as a result, decision quality may suffer and that mindfulness, the state of being openly attentive to and aware of what is taking place in the present, both internally and externally, can help people make better decisions. Figure 1 is an excerpt from the paper.
This post looks at the medical/health component of decision making as addressed in Gerd Gigerenzer’s new book, Risk Saavy, How to Make Good Decisions. First, Gigerenzer has contributed greatly to improving health decision making. This blog includes three consecutive posts on the Statistics of Health Decision Making based on Gigerenzer’s work.
He points out both the weaknesses of screening tests and our understanding of the results. We have to overcome our tendency to see linear relationships when they are nonlinear. Doctors are no different. The classic problem is an imperfect screening test for a relatively rare disease. You cannot think in fractions or percentages. You must think in absolute frequencies. Breast cancer screening is one example. Generally, it can catch about 90% of breast cancers and only about 9% test positive who do not have breast cancer. So if you have a positive test, that means chances are you have breast cancer. No! You cannot let your intuition get involved especially when the disease is more rare than the test’s mistakes. If we assume that 10 out of 1000 women have breast cancer, then 90% or 9 will be detected, but about 90 of the 1000 women will test positive who do not have disease. Thus only 9 of the 99 who test positive actually have breast cancer. I know this, but give me a new disease or a slightly different scenario and let a month pass, I will still be tempted to shortcut the absolute frequencies and get it wrong.
Gerd Gigerenzer has a 2014 book out entitled: Risk Saavy,How to Make Good Decisions, that is a refinement of his past books for the popular press. It is a little too facile, but it is worthwhile. Gigerenzer has taught me much, and he will likely continue. He is included in too many posts to provide the links here (you can search for them). My discussion of the book will be divided into two posts. This one will be a general look, while the next post will concentrate on Gigerenzer’s take on medical decision making.
As in many books like this, the notes provide insight. Gigerenzer points out his disagreements with Kahneman with respect to heuristics all being part of the unconscious system. As he notes heuristics, for instance the gaze heuristic, can be used consciously or unconsciously. This has been a major issue in my mind with Kahneman’s System 1 and System 2. Kahneman throws heuristics exclusively into the unconscious system. I also side with Gigerenzer over Kahneman, Ariely, and Thaler that the unconscious system is associated with bias. As Gigerenzer states: “A system that makes no errors is not intelligent.” He interestingly points out the use of the gaze heuristic by Sully Sullenberger to decide to not return to LaGuardia, but instead to land in the Hudson River.