As the global population ages, understanding the impact of aging on cognitive abilities becomes increasingly crucial. One such cognitive function that exhibits significant changes with advancing age is reaction time (RT). This article presents a comprehensive analysis of RT in older adults, examining its underlying mechanisms, age-related changes, and implications for cognitive functioning. Through a review of existing literature, this study explores various factors influencing RT in older individuals, including sensory, motor, and cognitive processes. It highlights how age-related changes in the central nervous system, such as declines in processing speed and neural efficiency, play a significant role in prolonging RTs. Additionally, the role of cumulative life experiences and environmental factors in shaping reaction time in older adults is discussed.