Lead
Since the baby was born, the two-and-a-half-year-old has been asking for a bottle. The toilet is not making it in time anymore. "Carry me" has become the refrain of every hour. Things that used to happen without a second thought have stopped happening.
When parents see this "going backward," two feelings tend to arrive together. The first is sympathy: the older one must feel left out. The second is anxiety: is this a sign of something wrong? Most parenting books are written in the language of the first feeling; they are less good at articulating the second with any precision.
This article uses the language of empirical research, not impression, to lay out what actually happens to a firstborn when a younger sibling arrives. How common is regression? How long does it last? And where is the line where "this warrants a conversation with someone" begins? The goal is to give parents at least a rough way to distinguish developmental regression from regression as an SOS.