Understanding object permanence is a key milestone in your baby's development – and represents a huge leap in your baby's cognitive skills. Until they grasp the idea of object permanence, babies don't know that toys, other objects and even people exist when they can't see them.


"Learning that something they can't see is still there is a big step in the process of learning how the world works," says Dr Amanda Gummer, founder of the Good Play Guide.

What exactly is object permanence?

Very simply, having a sense of object permanence means understanding that things go on existing even if you can't see them.

Object permanence was first defined by the Swiss psychologist Jean Piaget¹, as part of his overall theory of cognitive development in childhood. It has played a very important part in developmental psychology ever since.

Piaget found that if he showed a very small baby a toy and took it away, the baby didn't look for it – even if they liked the toy and weren't happy that it had disappeared. As far as the baby was concerned, it was there – because they could see it – and then it was not there. They didn't yet have the ability to know that the toy still existed.

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But, found Piaget, an older baby reacts differently: they would look for the toy that had been taken away and try to get it back because they realised that it must be somewhere, even if they couldn't see it.

From this, Piaget developed his concept of object permanence: that babies are not born with it but develop it in their 1st year.

At what age do babies learn object permanence?

Piaget's finding set the age at which babies develop object permanence at around 8 months. However, child development experts today believe babies start to develop object permanence much earlier, moving gradually through different developmental phases:

  • 0 to 3 months. Your baby likes to look at human faces, and learns to recognise the look (along with the smell and feel) of the people who care for them. (That's where that first real smile comes in, as your not-so-newborn suddenly picks you out with delight.)
  • At about 3 months. Your baby starts to notice and recognise objects. They can identify their familiar and favourite things, like toys or nappies, and they're starting to direct their own gaze and movements.
  • From 4 to 6 months. Your baby starts to realise that if something they're looking at is partly hidden, they can recognise and reach out for it – and if they throw or drop something, maybe you'll bring it back (as many parents know all too well!). But they still don't make all the connections, and a game of peekaboo is still a delightful surprise for them.
  • At around 8 months. This is when your baby really starts to'get' it. If you show them a toy and then you hide it while they watch you, they'll look for it because they realise it still exists and must be somewhere. And a game of peekaboo is all delicious anticipation and giggles, as they wait for you to reappear: they know you're there, they know you're hiding behind your hands and they know you'll be back... but when?
  • From 12 months. Your baby can look for things you've hidden and, by 2 years old, they can turn the tables and play with object permanence themselves: they’ll hide things for you to find and start to take the 'hiding' role in peekaboo.

Why is object permanence a key developmental skill?

Object permanence is a key part of a child's understanding of the world, how it works and how they fit into it. It helps them develop their cognitive and thinking skills along with their memory, because they're thinking about where something was, remembering and looking for it.

Understanding object permanence helps your baby them explore the world, and introduces them to the world of pretend play – and play is how children learn about the world and how to deal with it. And because a sense of object permanence widens their understanding, it also helps your baby with language.

"It's a precursor for things like empathy, problem-solving or creative thinking," says Dr Amanda explains. "If your world is only what you can perceive directly around you, it's difficult to imagine other things. So object permanence is a precursor for imagination too."

Along with that, your baby is learning some very important things about people: that people can go away, but they'll come back again. And that's one of the key things they need to know in order to feel secure enough to try new things. It helps to creates a feeling that they are safe.

Best toys for developing object permanence

There are specialist toys to help develop object permanence (see What is an object permanence box?, below), and there are everyday ones too. Try some of these:

  • A simple multipurpose muslin. To cover up a favourite toy and then whisk away to reveal it again. 
  • Plastic stacking cups. A source of endless pleasure, as you (or they) lift them up and put them down over small toys.
  • Lift the flap books and play gym accessories. 
  • Any box with a lid, which they can put things in and take them out of.
  • ‘Lock and key’ toys. Great for older toddlers, who will be aware – and excited – that something is waiting behind the doors, and which will help them hone their fine motor skills.

For ideas on how to play games that will stimulate your baby's concept of object permanence, see What games and activies with help my baby to develop object permanence?, below.

Object permanence does have a less fortunate flip side: it can make separation anxiety worse. And that's because object permanence applies to people as well as inanimate objects.

A young baby who hasn't yet 'got' object permanence will adjust much more quickly to a loved one leaving their presence. "There's no ability to predict what happens next. It’s just, 'They've gone,'" says Dr Amanda. "So they may cry because you've left but after that they'll settle more quickly." An older baby, however – one that's developed an understanding of object permanence – will react differently, often trying to follow the loved one who has left or at least trying to see where they've gone. And they may feel anxious about not being able to find them for quite some time.

Separation anxiety is something that affects quite a lot of babies and small children, from around 6 months on, as they become more aware of what's going on in the world around them and start wanting to explore things a bit. By now, they've also developed a strong attachment to their particular people – the ones who take care of them and they feel safe with. So, at the point where they develop object permanence, they may already be feeling more anxious about being left.

It can be hard to deal with if your child is unhappy because they can't be with you – but the important thing to remember is that this is because they do feel safe and loved, and at the same time they need to know that their loved adults do come back for them. Don't brush it off: reassure them and find ways to say goodbye that make them feel better. "If you go into a different room, make sure they can still hear you doing things when they can't see you," says Dr Amanda. "That helps reduce the anxiety and strengthens the idea of object permanence too."

But also remember that this is part of baby development, and it's a stage – that passes – like any other.

If you've heard of this, try not to worry too much. There are some theories that people with attention deficit hyperactivity disorder (ADHD) have particular problems with object permanence. This can worry parents whose babies don't seem to be getting the concept as quickly as their peers.

However, it's very rare for children to be diagnosed with ADHD before around school age at the youngest – and certainly not at baby or toddler stage. Don't take this alone as anything to worry about. Although, of course, if you do have specific concerns, talk to your health practitioners and ask for advice.

What games and activities will help my baby learn object permanence?

To help your baby learn object permanence, you can play:

Peekaboo. Sitting or standing close to your baby, cover your face with your hands or a blanket. Then open your hands or remove the blanket and say in a loud, happy voice, "Peekaboo!" Repeat. Don't cover your face for more than a couple of seconds to begin with and always show a lovely, smiley face when you reveal yourself: this way your baby will understand that this game is fun – and the repetition will start reinforce the idea that you haven't actually disappeared when your face was hidden.

Hiding games. Babies and toddlers are a little too young for 'real' hide and seek but you can play a fun version of it with toys. You'll need to accompany it with an explanation – "Here's Teddy, now I'm going to hide Teddy, where's Teddy gone?" Don’t hide Teddy anywhere too complicated, at least to start with. You could just hide Teddy under a blanket or your top, and then pull the toy out for the big reveal.

What's behind the flap? Sit your baby on your lap and look at a lift-the-flap book or a toy with a lift-up flap. Lift up the flap and accompany the reveal with an excited voice.

The cardboard tube game. 'Post' a plastic ball (or a squished up ball of kitchen paper) through an empty cardboard tube to see it emerge the other end.

The scarf in the tissue box. Cram a lightweight scarf into an empty tissue box and then slowly pull it out.

All of these games are teaching your child that things go away and come back in a way that's fun and – and, as they grow older and can lift flaps and pull scarves on their won, in a way that's under their own control.

But remember, says Dr Amanda, that it's a gradual process, not a sudden overnight skill. "It's not something you need to force or rush," she says. And you certainly don't want to focus on this alone. "Object permanence is part of cognitive development, that's for sure, but remember your baby also needs to flourish emotionally and physically. Playing in lots of ways is how they thrive best."

What’s an object permanence box?

An object permanence box is a toy used in Montessori learning to help children grasp the concept. It is used for babies of around the crucial age of 7 to 8 months, as part of the Montessori ethic of simple, sensory-based materials and hands-on learning. 

You can make an object permanence box by using a cardboard (or wood) box with a lid and a small toy (make sure the toy isn't small enough for your baby to swallow or choke on). Cut a hole in the lid of the box so your baby can ‘post’ the toy through, and another hole in the side so they can retrieve it. Playing with this box, over and over again – and of course you can vary the toys – will teach your child they can ‘make’ things disappear and then find them again – and it’s all within their own control. 

If you prefer, you can of course buy a box, like this Wooden Object Permanence Box with Tray (pictured).

object permanence box

About our expert, Dr Amanda Gummer

Dr Gummer is has a PhD in Neuropsychology, the Postgraduate Certificate in Higher Education and over 20 years’ experience working with children and families. She created the Good Toy Guide in 2012 and regularly appears in the media to talk about children and play.


1. Scott HK, Cogburn M.Piaget. [Updated 2023 Jan 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing, 2023 Jan

Pics: Getty




Radhika is a journalist who specialises in parenting, health and mental health issues. She writes for newspapers including The Guardian and the Mail on Sunday and edits reports for a wide range of bodies and thinktanks. She is a contributing author of Watch My Baby Grow (Dorling Kindersley)