You are rolling a toy truck to tim, and infant, when the truck rolls out of sight. if tim makes an effort to search for the truck, he is exhibiting:

In the given question, Tim is exhibiting object permanence.                

Explanation:

Object permanence is the comprehension that an object continues to exist even when it cannot be perceived in any way which means that when object cannot be sensed ( heard,seen,touched).  

It is a basic concept of developmental psychology, that deals with the development of young children's social and mental capacities. It was studied and presented by developmental psychologist Jean Piaget . According to Piaget, object permanence is a significant developmental stage in the first two years of a child’s life. Piaget proposed a series of 6 stages which describes when and how object permanence advances  during the first two years of life.  Children first begin to develop an idea of object permanence at around 8 months old. Other studies shows that this ability begins at a younger age.

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