What is the average reaction time during the night?

• A. 1.6 seconds
• B. 2.0 seconds
• C. 3.0 seconds
• D. 2.5 seconds

Answer: (D)

Night conditions slow perception and decision-making, increasing the time from noticing a stimulus to starting a response. Reaction time is made up of noticing, thinking about what to do, and then moving to act. Because fatigue and reduced visibility at night generally extend these processes, the average nighttime reaction time is typically longer than daytime, with about 2.5 seconds being a commonly cited value in training materials. That makes 2.5 seconds the best fit among the choices. A 1.6-second reaction time is more typical of daytime performance, 2.0 seconds is plausible but not as representative of night, and 3.0 seconds would indicate a longer delay than usually observed, even at night.