Reaction Time and Chronological Age

Abstract

Although the literature dealing with reaction time is enormous, no studies seem to have appeared of the relationship between reaction time and chronological age in a large group of individuals having a wide span of age limits. It seemed desirable that this relationship be studied.

We employed 150 individuals, sampled at random and ranging from the ages of 4 years to 60 years, grouped, for convenience, as shown in Table I.

Our purpose being to determine the reaction times to light and sound, 2 simple arrangements were constructed. For light, an ordinary 50 watt electric light was placed in series with one of the poles of a double throw switch, the other pole being in series with a signal magnet, recording on a moving drum, the operator's key, and the subject's tap key, the response recorded by tapping the key and breaking the circuit, The apparatus for sound consisted of a signal magnet in series with the operator's and subject's tap key placed in the primary circuit of an induction coil, with a set of head telephones in the secondary circuit.

The subjects were always seated with arm and body in the same position and given the simple instructions necessary. The experimenter's operations and recording devices were not visible to the subjects who were told that they would have a number of practice trials before the actual recording was begun. The number of practice attempts was arbitrarily determined by the operator from the nature of the responses; if it seemed advisable to allow more attempts to make the necessary neuromuscular adjustments, it was done. Final calculations were made from the subject's 5 best responses.

Averaging the times for males and females separately in each group (Table II), we find that males always respond more quickly than females, especially in childhood and late maturity, the figures closely approximating each other in the third decade.