Studies concerned with the synchronous emergence prediction of Piaget's structures-of-the-whole principle are discussed in conjunction with three groups of concrete-operational skills: (1) transitivity/conservation/class inclusion; (2) double classification/double seriation; and (3) ordinal, cardinal, and natural number concepts. Findings show that contrary to the principle, asynchronous emergence of stage-related skills appears to be the rule rather than the exception. Children appear to grasp the relevant relational skill before they grasp the corresponding classificatory skill: transitivity is understood before class inclusion; double seriation is understood before double classification; ordinal number before cardinal number. It is suggested that the specific asynchronies considered are not isolated idiosyncratic phenomena but instead are part of some underlying pattern in the growth of human logic that is not yet fully understood. It may be that the ontogenesis of logical thought mirrors the axiomatic development of logic itself. (Author/CS)