Why didn’t anyone tell me that my young baby doesn’t know objects exist when they are out of his sight?

This developmental milestone, called object permanence, refers to the understanding that objects continue to exist even when they cannot be seen, heard, or touched. During the first few months, your baby believed the world existed of only things she could see.

The Importance of Object Permanence

Mastering the concept of object permanence is a major developmental milestone in a baby’s life. Sometime after four months, your baby will begin to realize that the world is more permanent than they thought.

Prior to this time, your baby believes something "out of sight, is out of mind." For example, if you hid a toy under a cloth, your baby would not look for it.

Having object permanence helps babies understand the world and know what to expect next. When you hide a toy under a blanket, your baby will expect to see the toy when she picks up the blanket. Your baby learns that he doesn’t need to be frightened to give something up, he will get it back.

Also important to object permanence is realizing that other people exist, even when they leave. Up until this point, your baby did not have the ability to keep you in his mind. Although he still might not be happy when you leave, he can think about you when you’re gone, and realize you will return. Over time, your coming and going will not cause him as much distress.

Helping Your Baby Understand His/Her World

Your baby is likely to experience separation anxiety around the time he begins to understand the concept of object permanence. Once he understands that you still exist, even though he can’t see you, it’s not surprising he would object and cry for you to come back.

To help ease your baby through this separation anxiety period, move from his line of sight and then peek back around the corner to let him know that you are not far away. Increasing the time that it takes to reappear by just a little will help him relax, knowing that you will return soon.

Creating daily routines and a nurturing environment provides children with a sense of stability and trust in their caregivers. Your baby will realize over time when you leave, you will come back and he will be better able to tolerate brief moments of separation.

Games of peek-a-boo are great ways to help your baby learn about object permanence and develop trust in his environment.