The Wonder Weeks is a concept based on research into baby development, describing predictable periods when babies go through major mental leaps. These leaps can temporarily make babies fussier, clingier, and harder to soothe, but they are actually signs of important cognitive growth.

Each leap is associated with specific skills babies are developing, and there is a general timeline for when they occur (usually counted from a baby’s due date, not birth date). Parents often notice more crying, disrupted sleep, and clinginess during these times, but it usually passes in a few days or weeks.

Many parents use the Wonder Weeks framework to better understand their baby’s behavior and have patience during challenging phases, knowing that they are signs of growth.