Cognitive decline, socioemotional change, or both? How the science of aging can inform future research on sacrificial moral dilemmas.

Older adults comprise the fastest-growing population in the United States. By exercising their right to vote, guiding the value systems of future generations, and holding political office, they shape the moral context of society. It is therefore imperative that we understand older adults' capacity for moral decision-making. Although the vast majority of research on moral decision-making has either focused specifically on younger adults or has not considered age, recent work points to age-related differences in sacrificial moral decision-making, with cognitively healthy older adults making more deontological decisions relative to younger adults. Although only a small number of studies have to date examined age-related differences, there is a wealth of relevant literature on cognitive aging, as well as on sacrificial moral decision-making in younger adults, that point to possible mechanistic explanations for the observed age-related differences. The goal of this review is to situate these age-related differences in sacrificial moral decision-making in the context of these existing literatures in order to guide future, theory-informed, research in this area. We specifically highlight age-related decline in cognitive abilities purported to support utilitarian moral decision-making in younger adults, along with age-related changes to socioemotional information processing as potential mechanistic explanations for these age-related differences. The last section of this review discusses how age-related neural changes may contribute to both cognitive decline and motivational shifts, highlighting the importance for future research to understand brain-behavior relationships on the topic of sacrificial moral decision-making and aging.