Growth and development across the lifespan
Expect items mapping age to expected milestones — Erikson's psychosocial stages, Piaget cognitive stages, Denver II milestones, motor and language windows. The testable judgment is recognizing a developmental delay vs. normal variation (e.g., walking by 15 months is normal; not by 18 months warrants referral).
Pitfall: Candidates confuse "average" with "expected by" — NCSBN cares about the latest age at which a milestone should appear, not the average.