When discussing cognition in midlife, it is important to distinguish between fluid vs. crystallized intelligence. Fluid intelligence refers to raw processing power, specifically aspects of attention, memory, and processing speed. Crystallized intelligence refers to learned skills, including funds of information, verbal knowledge, and knowledge of social conventions. Fluid intelligence declines in midlife. The raw ability to process new information slows down. Consider the ease in which a teenager or young adult learns new technology compared to the difficulties middle-aged adults often face mastering the same task. On the other hand, crystallized intelligence increases steadily throughout middle adulthood. In fact, aspects of complex reasoning, verbal ability, and spatial processing peak in middle adulthood and only slowly decline thereafter.