Choice reaction times were measured for 6 adult Ss by 2 procedures. There was a Single-Choice condition in which, after a fixed warning interval, S was required to move a lever away from himself or toward himself according to which of 2 signal lamps was lighted. In the doublechoice condition, there followed J sec. after the 1st signal a 2nd choice involving 2 other signal lamps and a choice by the other hand. For each S, mean reaction time for the Single-Choice condition was reliably shorter than that for the 1st choice in the Double-Choice condition. This was regarded as corroboration of Poulton's thesis that a person's manner of response, including latency, is influenced by his expectations of the requirements of the immediate future.