Comparative Risk: Good or Bad Heuristic?

Abstract

Heuristics and biases infect all human thought, leading to irrational thinking and behavior. Bioethics must recognize this psychological reality and develop new models for evaluating and supporting autonomous choice, as Blumenthal-Barby (2016) argues (Blumenthal-Barby 2016).

Simply trying to eradicate heuristics and biases from medical decisions will not work and is deeply misguided. In many situations, a heuristic or bias can provide a shortcut to an effective decision (Gigerenzer 2008) or can counter the impact of other heuristics and biases. It is often impossible to determine whether a heuristic or bias harms or helps a decision, because of the complexity of thought and the difficulty of defining and measuring the quality of a decision or its rationality.

The debate over whether patients should receive comparative risk information highlights these practical, ethical, and conceptual quandaries. Some experts have argued that patients facing certain types of choices should not be told whether their risk is above or below average, because this information may trigger a bias (Fagerlin et al. 2007). But careful consideration shows that the comparative risk heuristic can usefully guide decisions and improve their quality or rationality. Building on an earlier paper of mine (Schwartz 2009), I will argue here that doctors and decision aids should provide comparative risk information to patients, even while further research is conducted.*