Looks for hidden object
Typical Timing & Development Window
Visual Timeline & Milestone Benchmarks
What these numbers mean
The average age babies first begin showing early signs of this skill. Before this, it's simply too early — there's nothing to worry about.
The midpoint age: half of babies have reached this milestone by here, half a little later. It's a typical target, not a deadline.
How spread out the timing is. About two-thirds of babies achieve it within one standard deviation of the median (the shaded band, wk 44–52). Wide bands mean a normal range of variation.
A gentle check-in point. If your baby hasn't shown this by around here, it can be worth mentioning to your pediatrician — most often it's still perfectly fine, just later.
About this milestone
The infant searches for a toy or object that they saw a caregiver hide under a blanket or cup. This indicates a solid grasp of object permanence—the understanding that objects continue to exist even when out of sight. It is a major milestone in memory development and spatial reasoning.
- 1. Play simple peekaboo games, hiding your face behind a scarf or your hands and then revealing yourself with a smile.
- 2. Use nested cups, hiding a small ball under one cup and letting them lift the cup to discover the ball.
- 3. Read interactive 'lift-the-flap' books, encouraging them to open the flaps to see what is hidden underneath.
- 1. Avoid using very small hiding objects that could be a choking hazard during search games.