How Dopamine Decline and the Positivity Effect Shift Type 1 and Type 2 Thinking in Aging

Aging is associated with predictable shifts in cognitive processing, including increased reliance on intuitive judgments and reduced engagement in effortful deliberation. Dual-process theories describe these two modes of thinking as Type 1 (intuitive, automatic) and Type 2 (deliberate, slow); however, the mechanisms responsible for age-related changes in thinking remain largely unintegrated across multiple bodies of literature. This review synthesizes evidence from dual-process models of reasoning, dopaminergic aging, and socioemotional selectivity theory to explain how motivational and affective changes shape cognitive processing across the lifespan. Age-related dopamine decline reduces the perceived value of mental effort, resulting in increased effort discounting and a decreased likelihood of engaging Type 2 reasoning. Concurrently, emotional goals shift to favour emotionally meaningful information in the present, producing the positivity effect and biasing attention and memory toward emotionally salient information, thereby strengthening intuitive processing. These mechanisms lead to increased reliance on Type 1 thinking and selective engagement of Type 2 reasoning when information is emotionally significant, conflict is detected, or sufficient motivation exists to justify cognitive effort. These changes reflect adaptive and strategic allocation of cognitive resources rather than generalized cognitive decline. Integrating neurobiological, motivational, and emotional perspectives clarifies how aging reshapes cognition in goal-consistent and efficient ways.