Commentary on “Projection of Care Partners’ Preferences in the Proxy Assessments of Everyday Preferences for Persons With Cognitive Impairment”

“Projection of Care Partners’ Preferences in the Proxy Assessments of Everyday Preferences for Persons with Cognitive Impairment,” by Wilkins and colleagues, applies a standard method in the study of cognitive biases to daily decision-making in care for older persons with cognitive impairment. Person A, who has cognitive impairment, reported their own preferences for daily hygiene and diet practices, social contact, and leisure activities. Person B, who provides care to Person A, also reported their own preferences, as well as the preferences they believed Person A held. In this study, as in many other studies that have asked participants to report on another person's preferences, Person B's reports of Person A's preferences actually resembled Person B's own preferences to a greater degree than they resembled Person A's preferences. This cognitive bias is robust across a number of topics, and goes by various names including assumed similarity (Person B mistakenly believes that Person A's preferences are more like their own than is actually the case), projection bias (Person B is unable to accurately imagine what they would prefer if in Person A's circumstances), and failed perspective-taking (Person B is unable to fully discount their own viewpoint and adopt Person A's). The cause is likely to be some combination of what are simplistically called “nature” and “nurture:” both how the human brain functions as a biological system and how people learn, through socialization, to take into account how other people think and feel.