Child's Developmental Milestones

An infant presents to the pediatrician for a routine check-up. His mother reports that he plays
peek-a-boo at home, waves bye-bye, and will say “dada.” He cannot yet drink from a cup. He seemed somewhat apprehensive when the physician entered the room. He can lift his head when lying on his stomach, sit unassisted, and stand with help. He has a positive Babinski’s reflex. If this infant has met all his developmental milestones appropriately, how old is he?

(A) 4–5 months
(B) 7–11 months
(C) 12–15 months
(D) 18 months
(E) 24 months

Answers And Discussion:


Correct Answer is (B) This baby is displaying motor, social, verbal, and cognitive skills appropriate for a 7- to 11-month old baby. A 7 to 11-month-old baby should be able to sit alone, crawl, and stand with aid. He is displaying age-appropriate social skills such as playing peek-a-boo and displaying stranger anxiety. He is displaying age-appropriate verbal and cognitive skills such as saying “dada” even in a nonsensical manner. Babinski reflex ordinarily disappears by 12 months of age.

Answer A is incorrect. A 4- to 5-month-old baby can sit with support. In terms of motor development he can follow objects to midline, put his feet in his mouth, and laugh aloud.

Answer C is incorrect. A 12- to 15-month-old baby can use a pincer grasp and demonstrates stranger anxiety. He can turn to someone speaking to him and can gesture to objects of interest and use different sounds to convey meaning.

Answer D is incorrect. An 18-month-old child can climb stairs alone and demonstrates hand preference. He can stack three cubes, kick a ball, and use two-word sentences and demonstrates at least a 250-word vocabulary.

Answer E is incorrect. A 24-month-old child has high activity level, can walk backward, and turn doorknobs. They are often selfish and imitative. They can stack 6 cubes and stand on tiptoes.