Is This Normal?

The CDC publishes checklists at 2, 4, 6, 9, 12, 15, 18, 24, and 30 months and 3, 4, and 5 years, each set at the age by which at least 75% of children do the skill.^1,6 A sampler: by 2 months, most babies smile when you talk to them and hold their head up on tummy time¹; by 6 months, most laugh, roll from tummy to back, and know familiar people³; by 9 months, most sit without support and look when you call their name⁴; by 1 year, most pull up to stand, wave bye-bye, and call a parent "mama" or "dada".⁵

Per Stanford Children's: "Most children will have at least 6 to 8 colds a year," more with daycare.⁹

Per the NIH: "5 out of 6 children experience ear infections (otitis media) by the time they are 3 years old."¹⁰

Per the Mayo Clinic, strep is most common in school-age children; testing isn't usually even recommended under age 3 because it's so infrequent in that group.¹¹

According to Stanford Children's, babies typically start sleeping through the night (6–8 hours) around 3 months¹⁴; according to the Cleveland Clinic, most babies manage 5–6 hour stretches without a feeding by 6 months, some as early as 4.¹⁵ And the AAP reframes the whole question: "a good sleeper is a child who wakes up frequently but can get himself back to sleep."⁸

According to the AAP, most children are physiologically ready around 18 months but "usually not cognitively ready… until sometime after their second birthday."¹⁶

Per the AAP: "Once your toddler can climb out of their crib, it may be time to transition to a 'big kid' bed."¹⁷