Guessing patterns differ between children of lower and middle class. It is hypothesized that lower class children, because they live in an environment affording fewer rewards for problem solving, come to expect a lower degree of success than their middle class peers. Eighty white kindergarten children attending urban public school were divided into groups of lower and middle class and given a two-choice card task. Two maintained and shifted card ratios were presented. Results lend support to the above hypothesis as the lower class children displayed less variable behavior on binary-choice responses. Social class similarities in problems solving behavior are also discussed. (Author/MK)