What is a developmental milestone?

• A. A genetic marker present at birth.
• B. An ability or specific skill that most individuals can accomplish in a certain age range.
• C. A measure of heart rate variability.
• D. A milestone is only observed in late adolescence.

Answer: (B)

Developmental milestones are the typical skills or abilities children acquire within expected age ranges as part of normal growth. They span areas like motor abilities, language, social behavior, and thinking skills, and they provide benchmarks to monitor how a child is developing. The best description is that a milestone is an ability or specific skill that most individuals can accomplish within a certain age window, because it reflects the normal pattern of development seen in many children. The other options don’t fit because a genetic marker at birth is a genetic indicator, not a skill; heart rate variability is a physiological measurement, not an age-related skill; and milestones occur throughout early childhood and adolescence, not only in late adolescence.