When a baby realizes that an object still exists when it is hidden from sight baby understands the concept of object ?

  1. Jean Piaget
  2. Sensorimotor Stage
  3. Object Permanence

By Dr. Saul McLeod, published 2018, updated 2021


The main development during the sensorimotor stage is the understanding that objects exist and events occur in the world independently of one's own actions ('the object concept', or 'object permanence').

Object permanence means knowing that an object still exists, even if it is hidden. It requires the ability to form a mental representation (i.e. a schema) of the object.

For example, if you place a toy under a blanket, the child who has achieved object permanence knows it is there and can actively seek it. At the beginning of this stage the child behaves as if the toy had simply disappeared.

The attainment of object permanence generally signals the transition from the sensorimotor stage to the preoperational stage of development.

Blanket and Ball Study

Aim: Piaget (1963) wanted to investigate at what age children acquire object permanence.

Method: Piaget hid a toy under a blanket, while the child was watching, and observed whether or not the child searched for the hidden toy.

Searching for the hidden toy was evidence of object permanence. Piaget assumed that the child could only search for a hidden toy if s/he had a mental representation of it.

Results: Piaget found that infants searched for the hidden toy when they were around 8-months-old.

Conclusion: Children around 8 months have object permanence because they are able to form a mental representation of the object in their minds.

Evaluation: Piaget assumed the results of his study occur because the children under 8 months did not understand that the object still existed underneath the blanket (and therefore did not reach for it). However, there are alternative reasons why a child may not search for an object rather than lack of understanding of situation.

The child could become distracted or lose interest in the object and therefore lack the motivation to search for it, or simply may not have the physical coordination to carry out the motor movements necessary for the retrieval of the object (Mehler & Dupoux, 1994).

The A-not-B Error

The A-not-B error occurs when infants search for a hidden toy at the incorrect location when presented with two possible locations (Piaget, 1954).

The toy is repeatedly hidden at location A. After a short delay, infants are then allowed to reach for and retrieve the toy.

After a few trials the toy is then clearly hidden in location B. After a short delay, they are then allowed to reach for the toy.

Infants 8 to 10 months of age consistently reach to location A despite clearly seeing the toy hidden at location B.


Critical Evaluation

There is evidence that object permanence occurs earlier than Piaget claimed. Bower and Wishart (1972) used a lab experiment to study infants aged between 1 – 4 months old.

Instead of using a Piaget’s blanket technique they waited for the infant to reach for an object, and then turned out the lights so that the object was no longer visible. They then filmed the infant using an infrared camera. They found that the infant continued to reach for the object for up to 90 seconds after it became invisible.

Again, just like Piaget's study there are also criticisms of Bower's 'reaching in the dark' findings. Each child had up to 3 minutes to complete the task and reach for the object. Within this time period, it is plausible they may have successfully completed the task by accident.

For example, randomly reaching out and finding the object or even reaching out due to the distress of the lights going out (rather than reaching out with the intention of searching for an object).

Violation of Expectation Research

A further challenge to Piaget’s claims comes from a series of studies designed by Renee Baillargeon. She used a technique that has come to be known as the violation of expectation (VOE) paradigm. It exploits the fact that infants tend to look for longer at things they have not encountered before.

In a VOE experiment, an infant is first introduced to a novel situation. They are repeatedly shown this stimulus until they indicate, by looking away, that it is no longer new to them. In Baillargeon et al’s (1985, 1987) study, the habituation stimulus was a ‘drawbridge’ that moved through 180 degrees.

When a baby realizes that an object still exists when it is hidden from sight baby understands the concept of object ?

The infants are then shown two new stimuli, each of which is a variation on the habituation stimulus. In Baillargeon’s experiments, one of these test stimuli is a possible event (i.e. one which could physically happen) and the other is an impossible event (i.e. one that could not physically happen in the way it appears).

In the ‘drawbridge’ study, a coloured box was placed in the path of the drawbridge. In the possible event, the drawbridge stopped at the point where its path would be blocked by the box. In the impossible event, the drawbridge appeared to pass through the box and ended up lying flat, the box apparently having disappeared.

Baillargeon found that infants spent much longer looking at the impossible event. She concluded that this indicated surprise on the infants’ part and that the infants were surprised because they had expectations about the behavior of physical objects that the impossible event had violated.

In other words, the infants knew that the box still existed behind the drawbridge and, furthermore, that they knew that one solid object cannot just pass through another. The infants in this study were five months old, an age at which Piaget would say that such knowledge is quite beyond them.

APA Style References

Baillargeon, R. (1987). Object permanence in 3½-and 4½-month-old infants. Developmental psychology, 23(5), 655.

Baillargeon, R., Spelke, E. S. & Wasserman, S. (1985). Object Permanence in Five-Month-Old Infants. Cognition, 20, 191-208.

Bower, T. G. R., & Wishart, J. G. (1972). The effects of motor skill on object permanence. Cognition, 1, 165–172.

Mehler, J., & Dupoux, E. (1994). What Infants Know: The New Cognitive Science of Early Development. Blackwell Publishers.

Piaget, J. (1954). The construction of reality in the child. New York: Basic Books.

Piaget, J. (1963). The Psychology of Intelligence. Totowa, New Jersey: Littlefield Adams.

How to reference this article:

How to reference this article:

McLeod, S. A. (2018, June 06). Object permanence. Simply Psychology. www.simplypsychology.org/Object-Permanence.html

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When a baby realizes that an object still exists when it is hidden from sight baby understands the concept of object ?

How do infants come to understand that items exist even when out of sight?

During early infancy, babies are extremely egocentric. They have no concept that the world exists separate from their point of view and experience. In order to understand that objects continue to exist even when they are unseen, infants must first develop a mental representation of the object.

What does it mean if a baby doesn't look for an object that disappears?

It might sound a little clinical, but object permanence is just one of many important developmental milestones you get to enjoy with your little one. In a nutshell, object permanence means your baby understands that things they can't see — you, their cup, a pet — still exist.

At what age is an infant first likely to reach for a completely hidden object?

At around 10 months old, your baby will most likely have a full understanding of the concept of object permanence. For example, if you hide a toy underneath a blanket, he'll know to pick up the blanket and look for the toy.

When an infant believes an object no longer exists when they can't see it this is referred to as?

Object permanence is considered to be one of the earliest methods for evaluating working memory. An infant that has started to develop object permanence might reach for the toy or try to grab the blanket off the toy. Infants that have not yet developed this might appear confused.