FIGURE 7.5 Toddlers’ problem solving In the task used by Chen and Siegler (2000) to examine toddlers’ causal reasoning and problem solving, choosing the right tool for getting the toy required children to understand the importance of both the length of the shaft and the angle of the head relative to the shaft. Compared with younger toddlers, older toddlers had greater understanding of these causal relations, which led them to more often use tools, rather than just reaching for the toy, and to more often choose the right tool for the task.