Final answer:
Young infants lack understanding of object permanence because their cognitive abilities are still developing. Early research by Piaget suggests infants under 8 months don't search for hidden objects. However, later studies indicate that even very young infants may have some understanding of object properties before they display outward signs of object permanence.
Step-by-step explanation:
Understanding Object Permanence in Young Infants
The concept of object permanence is pivotal in the cognitive development of infants. Young infants fail to grasp this principle because their cognitive abilities are still maturing. Swiss psychologist Jean Piaget's sensorimotor stage, which spans from birth to approximately 2 years of age, describes this developmental phase. During this time, infants explore the world through their senses and motor activities, such as tasting and manipulating objects. Between 5 and 8 months of age, babies typically start to understand that objects continue to exist even when out of sight. However, earlier studies by Piaget showed that infants younger than this developmental milestone would not search for a concealed toy, indicating a lack of object permanence understanding.
Despite Piaget's findings, subsequent research has challenged his conclusions about young infants' cognitive capabilities. Research by Baillargeon and others suggests that younger infants, as little as 3 months old, might have a rudimentary understanding of the physical properties of objects. Through experimental setups where infants observed unexpected behaviors of objects, such as a truck seemingly passing through a solid box, researchers noted that infants spent more time looking at these improbable events. This suggests that infants have some understanding of object properties earlier than previously thought, although full concept of object permanence is typically developed later.
Cognitive milestones are important markers of a child's development. Just as they achieve physical milestones, they also reach cognitive ones, such as responding to verbal requests and recognizing human faces and voices. Yet, the development of object permanence is a process that unfolds over the first year of life, sometimes not fully realized until after infants become toddlers, at which point they engage in activities that showcase their grasp of object permanence, such as playing hide and seen.