A developmental analysis of early time concepts: the equivalence and additivity of the effect of interfering cues on duration comparisons of young children.

Young children compare durations correctly and explain their conclusions logically only when no interfering cues such as distance and speed are introduced. We investigated whether type of cue and additivity of interfering cues affect children's duration comparisons. 4- and 5-year-old children were asked to compare the burning times of pairs of partially synchronous lights differing in intensity, bulb size, or both. Those who erred tended to attribute longer duration to the brighter or larger bulb, brightness having a stronger interfering effect than size. Since brightness might qualify as "work" more than bulb size might, the finding that the former interferes more than the latter supports Piaget's basic claim of children's confusion of time with "work." The fact that bulb size interferes at all, which does not fit into Piaget's framework, may be explained in terms of children's inability to distinguish clearly between time-related and time-unrelated cues and their assumption of direct relations between dimensions. Additivity of interference did not emerge, indicating that the previous finding which suggested its existence--distance plus speed interfering with duration comparisons more than speed alone--should be reassessed in terms of type of interfering cues, that is, distance interferes more than speed with time.