why do we refer to infants above a year in months?

Question

For example we refer to infants over a year as 13 months, 16 months, 24 months, etc. Is there a reason for this convention?

In: Biology

Answer 1

If I remember correctly, infants grow at a far faster rate in their first two years than afterwards.

So a baby from each month to month can still be quite a notable difference. After that, the grows slows down, and so it becomes less meaningful to track changes per month and the changes per year becomes more noticeable.