An analysis of children's narrative composition and art revealed concurrent development at both a general structural level and at a fine-grained detail level. A three-part study investigated whether this general cognitive pattern would be maintained across a different range of tasks: literary composition, scientific reasoning, and working memory. In the first part of the study, subjects, 80 children (aged 4, 6, 8, and 10 years, selected from a middle socioeconomic population) who had average to high-average scholastic ability, were asked to make up individual stories about a child their own age who has a problem to solve. In the second part, the same subjects were presented with a balance beam apparatus and asked to predict and to explain the resting position of beam when weights were placed in varying amounts. In the third part, the children were given the Mr. Cucumber Working Memory Measure. Results supported the previous notions that children's cognitive development proceeds through the same sequence of steps in a given domain and that children go through the same sequence during the same range. At the group level, performance on the three tasks was shown to be structurally equivalent and statistically indistinguishable, and, although the performance of individual subjects revealed more variation, the same general pattern held. (Three sets of figures are included.) (JK)