Lead
"Average age for rolling over: 6 months." Your child is seven months old, and still hasn't rolled over.
The moment you read that line, something happens in your head. My child is behind. The thought returns several times that day. You reopen the book. You scroll social media looking for babies the same age. The thought interrupts you again at work.
This is not parental weakness. It is the strange gravity that the word average exerts. A number meant to summarize a whole population gets applied to a single child standing in front of you, and suddenly it looks like a passing line on an exam.
This article is about why population-level averages are often unhelpful — and sometimes actively harmful — when read against an individual baby, and how to develop language that protects you from comparing without punishing yourself.