ABSTRACT
In 1884-85, Francis Galton established an Anthropometric Laboratory at the International Health Exhibition in London, where he measured many human responses, including simple response time (RT). The participants, which incl uded nearly 1600 boys between the ages of 5 ~2 and 20 ~2 years, pressed a key as soon as they saw a light (Koga & Morant, 1923). Roughly 100 years later, I (Kail, 1991 b) administered an updated task-participants now pushed a button on a joystick when they saw asterisks on a computer monitor-to nearly 200 71/2-to 21-year-olds. The results of both studies, shown in Figure 5.1, demonstrate the developmental profile that has been revealed in countless other developmental studies: time to respond declines substantially
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6 8 10 12 14 16 18 20 22 Age (years)
Figure 5.1 Change in simple response time (RT) as a function of chronological age in years, separately for data published by Kaga and Morant (1923) and by Kail (I99Ib).
