Table 1:

Example Skills at Each Level

	Tasks common to developmental tests	Discrete skills prerequisite to IQ tests	Tasks common to IQ tests
Language	One-word receptive vocabulary	Following 3-step unrelated instructions	Verbal analogies; Comprehension
Motor	Gross and fine motor milestones	Hand-eye and bilateral coordination for object manipulation	Visuospatial processing (e.g., block design)
Categorization	Identical match-to-sample	Sorting object by where they are most likely to be found (i.e., concept formation)	Nonverbal Reasoning Semantic classification; Working memory; Matrices; Analogies (verbal or nonverbal)