Development & Milestones
Object Permanence & Peek-a-Boo
Object permanence is understanding that things continue to exist even when you can't see them. Develops around 4-7 months, fully established by 8-12 months.
Before object permanence: Baby thinks objects cease to exist when hidden ("out of sight, out of mind"). After: Baby knows you still exist when you leave the room, will search for hidden toys.
This cognitive leap explains why separation anxiety starts around 8 months - baby now knows you exist elsewhere and misses you!
What to Do
- Play peek-a-boo starting around 4-5 months (teaches object permanence)
- Hide toys under blankets and watch baby search for them (around 8-9 months)
- Play hiding games: Hide your face, then reveal it with "Peek-a-boo!"
- Drop toys from high chair: Baby will look down to find them (practices concept)
- Use this understanding to help with separation: "Mommy's at work, will come back"
- Make goodbye routines predictable - helps baby understand you always return
- Don't sneak away when leaving - undermines trust that you'll return
- This milestone is why babies start showing stranger anxiety and separation anxiety around 8-9 months
When to call a doctor
No medical concerns. Mention to doctor at well visits if baby shows no interest in interactive games, doesn't search for dropped toys by 12 months, or seems delayed in social development.