In the context of substitute decision-making, patients standardly appoint a single proxy to make medical decisions on their behalf. This single-proxy model makes sense: after all, many patients are reluctant to discuss what they would like to happen to them once they lose competence with a single individual, let alone several. Moreover, even when presented with the possibility of appointing multiple decision-makers to act on their behalf, most patients still prefer to appoint one person (Frey, Hertwig, and Herzog 2014; Frey, Herzog, and Hertwig 2018).
However, it is now well known that individual proxies exhibit appreciable unreliability. They frequently fail to accurately replicate decisions that the patient themselves would have made under the circumstances were they able (Shalowitz, Garrett-Mayer, and Wendler 2006). Meanwhile, a body of empirical literature suggests that group deliberation, under felicitous conditions, produces more reliable decision-making than reasoning performed by individuals. This seems to license the conclusion that our reasoning capacities are much improved when they are embedded in a dialogical context (Mercier and Sperber 2011).
We will argue that patients, in at least some cases, would be better served by appointing multiple proxy decision-makers to act on their behalf. We begin by outlining the evidence in favour of distributed decision making, before applying these insights to the context of proxy deliberation. Given the substantial difficulties besetting proxy decision making, we aim to show that there are significant benefits to moving to a distributed model involving multiple, jointly appointed, proxies.