Questions: Piaget's Sensorimotor Stage

Question 1

A 10-month-old watches you hide a toy at location A three times and successfully retrieves it each time. Then, while the infant watches, you hide the toy at location B instead. The infant searches at location A anyway. This behavior best illustrates:

• A. The infant has not yet developed any form of object permanence
• B. Object permanence at this stage is tied to action history rather than an abstract representation of the object's location
• C. The infant cannot visually track the toy being moved to location B
• D. The infant has fully developed object permanence but simply prefers location A

Answer: (B)

This is Piaget's A-not-B error. The infant clearly has some object permanence — they search for hidden objects. But the search is guided by their own prior action (repeatedly reaching to A) rather than a true abstract representation of where the object currently is. Full object permanence requires understanding the object's location independently of one's own action history, which develops later in the first year.

Question 2

Baillargeon's violation-of-expectation studies found that 3–4 month old infants look longer at physically impossible events. Why is this finding significant for understanding the sensorimotor stage?

• A. It proved that Piaget's entire theory of cognitive development was incorrect
• B. It showed that motor skills, not cognition, are the true limit on early infant behavior
• C. It suggested that infants have implicit knowledge of object permanence earlier than their search behavior indicates
• D. It demonstrated that object permanence requires language development to manifest in behavior

Answer: (C)

Baillargeon's work revealed that Piaget conflated two different things: the age at which knowledge guides active search behavior, and the age at which some implicit understanding exists. Infants looking longer at impossible events (a form of surprise) show they have expectations about how objects behave — even before they can reach for and search for them. This means the cognitive competence exists earlier than Piaget thought, but it isn't yet linked to purposeful action.

Question 3

At the very beginning of the sensorimotor stage, infant behavior is primarily driven by innate reflexes such as sucking and grasping, with no learning or modification yet occurring.

• T. True
• F. False

Answer: True

This accurately describes Piaget's first substage (0–1 month), characterized by purely reflexive behavior. The infant has no schemas beyond innate response patterns. Learning begins in the second substage, when infants start to repeat actions that produce interesting results (primary circular reactions). The progression from reflex to intentional action to symbolic thought is the core narrative of the sensorimotor stage.

Question 4

Object permanence is fully achieved by 8 months of age, when infants first begin to search for hidden objects.

• T. True
• F. False

Answer: False

The ability to search for a hidden object at 8–12 months is only partial object permanence. Infants at this age still commit the A-not-B error — searching where they previously found an object rather than where they watched it being hidden. Full object permanence, including correct search after invisible displacements, is not achieved until late in the first year or into the second year. Object permanence is a gradual construction, not an all-or-nothing milestone.

Question 5

What is the A-not-B error, and what does it reveal about the nature of object permanence in early infancy?

Model answer: The A-not-B error occurs when an infant who has repeatedly found an object at location A will still search at A even after watching the object being hidden at location B. It reveals that early object permanence is not yet a fully abstract representation of an object's location — instead, the infant's search is guided by their own action history (where they previously reached successfully). True object permanence requires understanding the object's location independently of one's own actions, which develops later.

The error matters theoretically because it shows that object permanence is not a simple on/off capacity. Even when infants 'have' object permanence in the sense of searching for hidden things, their representation is still partially action-tied. This is consistent with Piaget's core claim that knowledge in the sensorimotor stage is built from and embedded in sensorimotor activity, not yet truly abstract.