Piaget's sensorimotor stage (intellectual development)

Piaget principles AO1

• Believed children to be ‘lone scientists’

• Believed children are born with a set of basic, primitive reflexes/schemas which become more sophisticated through interacting with the environment & self-discovery

• Developed 4 stages of intellectual development

Sensorimotor stage features AO1

• 0-2 years

• Knowledge consists of simple motor reflexes which are unintentional (eg rooting reflex)

• Focus on physical sensations & develop basic use of language

• Around 8 months children begin to learn by trial & error & develop object permeance

Object permanence AO1

• The understanding that an object still exists, even when its hidden

• Develops at 8 months as children are able to form a mental representation of the object in their mind

Ball & blanket study aim AO1

To investigate at what age children acquire object permeance

Ball & blanket study method AO1

• Piaget placed a ball under the blanket whilst the child was watching & assessed whether the child attempted to retrieve the hidden object

Ball & blanket study findings AO1

• Infants under around 8 months typically made no attempt to search for the ball, suggesting they believed the object no longer existed once hidden.

• From 8 months children began to actively search for the ball, indicating the development of object permanence

Strengths AO3

• P - practical applications, particularly in early childhood education and childcare.

• Piaget’s theory highlights the importance of active exploration, sensory stimulation, and physical interaction with the environment during the first two years of life, leading to the Primary school review in 1966. As a result, early years settings often provide infants with hands-on resources, such as textured toys, stacking blocks, and cause-and-effect play equipment, to promote schema development. For example, activities like hiding toys under cloths directly support the development of object permanence, a key cognitive milestone of the sensorimotor stage.

• T - This application increases the ecological validity of Piaget’s theory, as it translates theoretical concepts into real-world practices that support healthy cognitive development. Therefore, the sensorimotor stage is not only theoretically influential but also practically useful, strengthening its value within developmental psychology.

Limitations AO3

• P - Piaget may have underestimated the cognitive ability of babies

• E - in his study of object permeance, Bower made an object ‘disappear’ by turning out the lights & then observed 5-month old infants attempts to retrieve the item in the dark using an infared camera. He found that infants continued to reach for the object in the dark for up to 90 seconds, therefore suggesting they had object permeance.

• T - t his indicates that object permanence may develop earlier than Piaget proposed (8 months), weakening the validity of his stage-based timeline. Consequently, Piaget’s findings may reflect limitations in his research methods rather than genuine cognitive inability, suggesting infant cognition is more advanced and gradual than his theory implies

• P - tasks may have further underestimated infants’ cognitive abilities because they relied heavily on motor responses.

• E - For example, in object permanence tasks such as the ball-and-blanket study, infants were required to physically search for a hidden object. However, younger infants may have understood that the object continued to exist but lacked the physical coordination and strength necessary to retrieve it as motor skills are still developing at 0-2 years. This creates a performance vs competence issue, where the infant’s failure reflects limitations in their motor skills rather than their cognitive understanding. Also, his study may be affected by low concentration levels rather than a genuine lack of cognitive ability. Infants have naturally short attention spans and are easily distracted, meaning they may not search for a hidden object simply because they have lost interest or forgotten the task

• T - Consequently, Piaget’s conclusions may lack validity because his methods measured physical ability and attention/memory rather than true cognitive development, implying that infant cognition is more advanced and development more gradual than the rigid stage theory suggests.

• P - limited sample which questions the generalisability

• E - Much of Piaget’s work was based on detailed observations of his own three children, resulting in an extremely small sample that is unlikely to reflect the developmental patterns of the wider population. His children were raised in a highly stimulating, intellectually enriched environment, which may have accelerated aspects of their cognitive development compared to children from different educational, cultural, or socioeconomic backgrounds. This introduces researcher bias, as Piaget acted as both parent and observer, increasing the risk of subjective interpretation of behaviour to fit his theoretical expectations. Furthermore, the lack of participant diversity means the theory may suffer from ethnocentrism, as it assumes universal stages of development without sufficient cross-cultural evidence.

• T - Consequently, the reliability and scientific credibility of Piaget’s conclusions are weakened, suggesting that his stage theory may oversimplify cognitive development by presenting it as more universal than it actually is.