Abstract
First graders were tested on trials requiring the discrimination and transposition of right-left relations, with stimuli similar to (dolls) or different from (toy planes) the body. On an initial series of training and practice trials children were allowed to respond to body and external objects as referents providing right-left cues. A later series of test trials was then used to determine the referent the child actually preferred. Results of the test trials indicated that 24 children tested with the dolls preferred the body as referent, while 24 children tested with planes preferred the external referent. The results were interpreted as suggesting two alternative systems through which children develop an undersranding of right-left relations and possibly other concepts as well.