About halfway through their first year, most babies are developing ‘object’ and ‘person’ permanence – they understand that someone still exists when they can’t be seen. Baby’s brain can now create a picture of something that they can’t see anymore.

Person permanence and forming attachment

Person permanence is thought to develop first. Often when babies reach this stage they become upset when their parent leaves the room. This development links in with the formation of an attachment relationship.

At about this same age, babies are recognising that the person who cares for them most is central to their safety and security, and they may become upset when this important person leaves them. This can be a surprise for parents, because a short time beforehand, baby didn’t seem to notice if they left the room.

Parents can reassure their baby by calling out to them if they’re close by.

Object permanence and anticipation

Before developing object permanence, if something was out of baby’s sight it was also ‘out of mind’. If a toy was hidden under a blanket, baby would think it had disappeared and wouldn’t look for it.

As babies begin to develop object permanence, they start reaching for a toy that’s partially hidden. They’re now able to understand that a whole object exists when they can only see part of it. At this stage, babies love to play peekaboo with their parents. They can now anticipate that their parents will reappear.

Object permanence continues to develop through the first year. By now, babies understand that an object may not be in the same place where they saw it last, and may actively look for it.

Babies’ understanding of object permanence is linked with:

  • developing memory skills that help them remember a person or object
  • motor and coordination skills that enable them to reach and look for hidden objects.


  • ‘Object’ and ‘person’ ‘permanence’ is an understanding that people and objects still exist when they can’t be seen.
  • Person permanence develops before object permanence, and in conjunction with forming attachment relationships.
  • Object permanence continues to develop over the first year.