A qualitative study of true self judgments, epistemic access, and medical decision-making.

BACKGROUND: Toomey et al (2024) found that US participants were more likely to follow a medical treatment preference-expressed after substantial cognitive decline-of a third person rather than their own future self. This correlated with a greater tendency to see the third person as still their true self. We hypothesised that the greater epistemic access one has to one's own true self as opposed to others might drive this difference. METHODS: A codebook designed to capture different kinds of evidence and reasoning was developed, and participants' explanations for their treatment decisions in Toomey et al's study were coded and qualitatively analysed. RESULTS: In first-person cases, participants were more likely to explain their treatment decision with reference to perceived direct access to their own true self. In contrast, in third-person cases, participants more often relied on proxies or heuristics, such as the presumption that an expressed preference is an authentic one or that preferences expressed with greater cognition tend to better reflect the true self. CONCLUSIONS: These findings support the hypothesis that differential epistemic access to the true self in first- and third-person cases may drive different medical treatment decisions. Participants may be trying to follow the patient's 'true' or 'authentic' preference in all cases, but relying on different kinds of evidence in so doing.