In addition to mental health, psychosocial and contextual factors significantly influence human cognition throughout all stages of life. These psychosocial factors can be broadly categorized into individual characteristics and the external social and physical environment, both of which can act as either risks that accelerate cognitive decline or protective factors that build cognitive reserve. Positive elements like strong social engagement, purpose, optimism, and self-efficacy play a role in protecting against decline. Negative factors such as depression, loneliness, and social isolation increase risk for decline in cognition. These influences involve complex, often bidirectional links, where mental states and social interactions shape brain function, affecting memory, processing speed, and other cognitive domains, with potential implications for dementia risk and overall cognitive aging.