Which one of the following statements is not correct?

Child development follows several well-established general principles: it proceeds from generalized, mass responses to specific, differentiated ones (the general-to-specific principle) -- for example, an infant's whole-arm swiping motion gradually differentiates into precise, controlled finger movements; it follows a spiral or zig-zag course rather than a strict straight line, revisiting earlier themes at higher levels; each developmental phase carries its own age-specific tasks and hazards (a principle highlighted in Hurlock's account of development); and although every child passes through the same broad sequence, the rate at which they do so is not the same for every child or every domain of growth.

Checking each of the four statements against these principles: describing each phase as having its own hazards matches the developmental-hazards principle; describing development as spiral rather than linear matches the zig-zag/spiral growth pattern; describing development as proceeding from general to specific matches the general-to-specific principle -- broad, undifferentiated responses becoming precise and specific ones. The statement that the rate of development is uniform, however, directly contradicts the well-established fact that developmental pace varies across individuals and domains -- making it the one statement that is not correct.

• "Each phase of development has its hazards" -- consistent with the developmental-hazards principle highlighted in Hurlock's account of development; an accurate statement.

• "Development is spiral and not linear" -- consistent with the recognised zig-zag/spiral growth pattern; an accurate statement.

• "Development proceeds from general to specific" -- consistent with the general-to-specific principle (e.g. whole-arm movement differentiating into precise finger movement); an accurate statement.

• "Rate of development is uniform" -- contradicts the established variability of developmental pace across children and domains; this is the inaccurate statement.

Since three of the four statements are well-supported developmental principles and only the uniform-rate claim is contradicted by evidence, the uniform-rate statement is the one that is not correct.