Jean Piaget (1896-1980) was the first person to study cognitive development. He believed that we possess some innate knowledge but the majority of knowledge is development by experiences which reorganise our schemas. The adaptation of schemas is the process by which an infant changes its mental model of the world to match more closely to how the world actually is. Adaptation occurs in 4 stages:
- Assimilation – the use of existing schemas to understand a new experience
- Disequilibrium – as the new information does not fit with existing schemas, an imbalance occurs so reorganisation or extension of schemas must occur
- Accommodation – new knowledge is used to produce a new or refine an existing schema
- Equilibrium – the evolved unit of knowledge used to understand and respond to a situation. The infant’s knowledge now fits into a schema so their understanding and mental models are balanced
The stages of development (which involve adaptation):
- Sensorimotor stage – 0-2 years – Children gain knowledge through their sensory experiences and by manipulating objects. They understand that they are separate from objects around them.
- Preoperational stage – 2-7 years – Children use pretend play, language and general symbolic function but still struggle with logic and egocentrism.
- Concrete operational stage – 7-11 years – Children think logically but rigidly, without abstract or understanding of hypothetical concepts.
- Formal operation stage – 12+ years – Children have increased logic and the ability to deduct reasoning and abstract.
Evidential support for Piagetian views: Within the sensorimotor stage is a concept called object permanence: the process by which we know that objects remain in our environment, even when they cannot be detected by the senses. Whether or not an infant has object permanence can be tested in search tasks. Piaget’s ‘blanket and ball’ technique involves a child being shown a ball which is placed under a blanket so it is no longer visible to them. It is then retrieved by the experimenter and placed in a different location. During which one of three things occur:
- No search: the infant does not have object permanence as they think the ball has disappeared.
- Simple search: the infant searches for the object successfully in the last place that it was placed when it is places in only one location.
- a-not-b search – the infant searches in the most recent place that the ball was retrieved 9when it is placed in tow locations), not put, despite seeing that it was placed elsewhere, showing that have not fully developed object permanence. These infants can complete the simple search. It is when they complete the a-not-b search that they have fully gained object permanence.
Piaget (1963) found that before 8 months infants made no search. Between the ages of 8 and 12 months, they can perform the simple search but if the a-not-b search is set up they will complete this unsuccessfully. Between 12 and 18 months, Piaget found that both tasks are completed correctly. Evaluation: he used family members and family friends’ infants, producucing a limited and unrepresentative sample. His results were qualitative and therefore more subjective, or more detailed and therefore better. The same children were used in his longitudinal study, reducing the extraneous variables arsing from participant variables. The pull of a blanket which measures object permanence is an accurate measurement which indicated for certain. However, Bower and Wishart (1972) gave infants aged between 1 and 4 months an object and then placed it away so they had to reach for it. As they reached for it the lights were turned out so the object was no longer visible. They were filmed using an infra red camera and it was found that infants continued to reach for the object for up to 90 seconds after they could no longer see the object. This suggests that infants much younger than Piaget suggested have object permanence as their continued reaching suggests that they still believe the objet exists in their environment, despite not being able to see it. Other studies support Bower’s and Wishart’s findings such as Baillargeon et al (1985) and Ahmed and Ruffman (2000). Evaluation: The measurement of time is quantitative and gives a certain indication of results. The sample was larger than Piaget’s and thus more representative of the wider infant population. However, the variables were not operationalised well – the extension of an arm to measure object permanence could be explained by many other things such as slow reactions and limited motor ability. Bower and Wishart and other psychologists therefore explain infant development by nature. The nativist approach states that we’re already equipped with advanced ways of thinking. The role of experience is still considered; our cognitions are believed to be elaborated due to experience. Our capabilities are built into our NS due to genetic instructions and persisted in the genome due to evolutionary fitness. This theory extends greater than just object permanence (as does Piaget’s). Evidence suggests infants at just weeks old possess: number sense and basic arithmetic (Wynn 1992) , cross modal sensory integration (Meltzoff and Barton 1979) and the ability and motivation to imitate others (Meltzoff and Moore 1977).
Sources: Pennington and McLoughlin (2009) AQA(B) Psychology for A2, Hodder Education: London