The choices and preferences of nursery school children.

After a period of equal reinforcement for choices of any job revealed which of 10 jobs each of 24 preschool children preferred and did not prefer, token payment became dependent on particular choices. Some children received tokens only for choosing previously non-preferred jobs, others for choosing previously preferred jobs. When tokens depended on choosing the nonpreferred jobs, those came to be preferred. When tokens depended on choosing the preferred jobs, the preferences were strengthened. The effects were replicated both within and between subjects, except in the case of one boy who consistently avoided token pay.