Adults and older children never give a second thought to the fact that when something disappears out of sight that it still exists. It never crosses our minds to think about when exactly did the ability to "just know"develop. If something ceases to exist that was once right in someone's hand right before our eyes we think we must be at a magic show. However, people don't know that when they were an infant they had to develop the knowledge that when you don't see something it still exists on earth. Technically, infants must be looking at a magic show everyday for months.
Piaget coined the term object permanence in 1954 to describe the understanding that objects continue to exist, even when they cannot be directly seen, heard or touched. While conducting an experiment on his son as Piaget often did he found that his son did not reach for a toy that he had hidden with a cover. Piaget took that to mean that his son must not know that they toy exists anymore. When Piaget started these experiments to test this phenomenon light bulbs lit up in the heads of developmental psychologists around the world as they probably said to themselves,"I never thought about that before". Since the emergence of the idea of object permanence many psychologists have conducted experiments to either prove or disprove Piaget's theory. Experiments to test the development of this phenomenon have been conducted for decades and continue to be a topic that many developmental psychologists study.
In his book written in 1954 Piaget stated that "for young infants objects are not permanent entities that exist continuously in time but instead are transient entities that cease to exist when they are no longer visible and begin to exist anew when they come back into view." He proposed the notion that infants do not begin to understand the object of object permanence until about the age of nine months. Piaget did a lot of experiments to test whether this was true. He came to the conclusions from his many experiments that an infant prior to eight months of age do not possess the understanding that because they cannot see an object does not mean that it does not exist (Siegler & Alibali,2005).
Piaget proposed that object permanence doesn't develop until during what he identifies as the sensorimotor stage. The sensorimotor stage he identifies as being from birth to about two years of age. Piaget broke the sensorimotor stage down into six sub stages. Piaget also broke down the idea of object permanence according to the sub stages of the sensorimotor stage. During the first stage of object permanence which is roughly between the ages of birth to one month old, an infant will look at an object only while it is directly in front of their eyes. However, if an object was to move to the left of right of an infants direct line of vision, the infant would no longer look at the object. During the second sub stage which lasted from one to four months, Piaget said that infants will look for an extended period of time to an area where an object had disappeared from. He said that an infant will not however, follow the object if it were to move out of their line of sight. In the third sub stage which is between the ages of four and eight months, an infant will anticipate where a moving object will go and they will begin to look for the object there. They will only do this though if the object is partially visible, they will not make an attempt to retrieve an item if it is completely...