Piaget's Model of Cognitive Development


Jean Piaget's model of intellectual development continues to have a profound impact on how children, their thinking and development are viewed. Piagetian theory and concepts (via a mass of publcations and empirical data) transformed the developmental psychology field of the early twentieth century Behaviourist leanings. It is considered that Piaget played a role of the same ilk in that realm as Darwin played in the evolutionary arena (Thomas, 1996).


Piaget's cognitive theory has its genesis in his background and the chronological timeframe of his academic world. He was born in Switzerland in 1896, and from an early age showed much promise with an abundance of precocity as a scholar with interests in biology. He had achieved a Ph.D. by the age of 22 years and experienced a period of directionless wandering around Europe,on the fringes of the embryonic psychological movement. It was at Binet's laboratory, administering standardized tests to young children, that Piaget ignited his lifelong interest in the thought processes of children. Piaget died in 1980 but is survived by a 'monumental' theoretical legacy in developmental psychology. (Flavell, 1996)

The 'Methode Clinique'

Piaget was the first theorist to recognise that children and adults had different cognitive processes. Miller (1993) contends (in Flavell, 1996:200) that Piaget altered the course of psychology with his unique observation and questioning techniques so that once "psychologists looked at development through Piaget's eyes, they never saw children in quite the same way." It is from this uniquely Piagetian mode of observing subjects in a 'father/experimenter' role in a semistructured interviewing approach that Piaget pioneered the 'methode clinique'. This significant contribution is still in use today, with most clinicians in this field utilizing variations in their research. For Piaget, it was important to probe the underlying understandings and knowledge bases in children's cognition, with repeated questionings and a focus on the reasonings behind their answers. Such novel insight was in contradiction to all previous understandings of this field. Flavell 1996:202 states that Piaget believed he could learn far more about child cognition "by noting and querying their incorrect answers than just by tallying their correct ones." It is from such 'clinical' intensity that provided the vast wealth of research data upon which Piaget based his cognition theory, much of which largely endures to the present day in some form. Piaget had the 'greenest thumb', in his rich empirical discoveries to reveal his model on the development of cognition. He "systematically ploughed his way through most of the principal modes of human experience and knowledge--- space, time, number, and the rest" (Flavell (1963) in Flavell, 1996:202).

Theoretical Orientation

Piaget's cognitive development approach became the springboard for all other intellectual theories. He was most concerned with the structures and growth of knowledge or 'genetic epistemology' and recognized that an excellent place to study such processes would be with young children. Piaget believed that cognitive development happens through the rich interplay of biological processes of maturation, neural development (Central Nervous System and memory) as well as language formation via the interaction of social learning experiences.A child's physical maturation in combination with sensory- motor development enables the active experiencing and discovery of the physical environment. Piaget believed that all thought begins with physical activity in the early stages of a child's development evolving in maturity with complex abilities to manipulate mental functions that are abstract/hyperthetical. Piaget's most famous metaphor to describe this endogenous or internally motivated process, is viewing the child as a 'little scientist' who experiments and explores his world. Social interaction as a source of learning was not emphasized by Piaget. When compared to the Russian cognitve theorist, Lev Vygotsky, Piaget's views are starkly contrasting. Vygotsky used he metaphor of the learning child as a 'little apprentice' with his teachers placed in the central role providing and supporting all possible learning situations. Such cognition is exogenous or externally motivated.

Basic Concepts of Piagetian Theory

Piaget was the first theorist to recognise the qualitative differences between child and adult intellectual abilities. He also believed that the child was very much the active learner in an age-stage process whereby the child progresses qualitatively through the stages of cognitive development in a two-pronged adaptive/interactive process which allows for new information to be fitted (assimilation)into already existing cognitive structures (accommodation).
Accommodation is defined by Lefrancois (1995) as the "modification of an activity or ability in the face of environmental demands." He defines its twin, assimilation, as the "act of incorporating objects or aspects of objects into learned activities" (pp.329-330).
The end product of this is called Equilibration which results in more effective ways of processing information from the environment. Lefrancois describes this process of equilibration as how "people maintain a balance between assimilation (using old learning) and accommodation (changing behavior; learning new things)" (p.335). This state of balance is pivotal in cognitive growth.It is necessary, according to Piagetian theory for children to progress through each stage in turn accommodating/assimilating towards the balances of equilibration and meeting the challenges of 'disequilibration' (cognitive conflict) through the child's life span to adulthood cognitive sophistication.
In this model,the phase termed 'Organization' stands alongside the Adaption level to describe the structures of human cognition. From this Piaget utilizes the concept 'Operation' to describe it as the "thought process... an action that has been internalised in the sense that it can be "thought" and is reversible in the sense that it can be "unthought" (Lefrancois,1995:342). Here Piaget proposes that the child develops through hierarchial quantitatively different stages, each building on the preceding one, towards an ever increasingly complex array of 'schemas'or knowledges of what is known about at a particular time. Lefrancois' explanation for a schema is simple; "a unit of cognitive activity together with whatever biology or neurology might underlie that activity... an idea or a concept" (p.345). An example of a schema's evolution is the innate ability of an infant to suck for sustenance at the breast eventually expanding the sucking schema to include similar behaviour with tiny fingers and hands, a bottle etc.

Piaget's Stages of Intelligence

Piaget contended that children developed their intelligence through a series of qualitatively differentiated stages and that their intelligence was radically different to that of adults. Such a notion was revolutionary for the times, where the prevailing belief was that children's cognition was the same as adults but less efficient in quantitative terms. Piaget maintained in his theory that children progressed through each of the stages in an 'invariance sequence'; that strictly in the same order(Sutherland,1992).
Many readings of Piaget's stage theory will notice that most academics acknowledge that he wrote about a four stage theory (Lefrancois, 1996). However, recently it has been mooted (by Flavell?) that there are really only three stages. This work will use the three stage framework.

The General Periods of Development

1. The sensorimotor stage; with six sub-stages, (birth to two years).
2. The stage of concrete operations, with two sub-stages- pre-operational thought (two to seven years) and concrete operations (seven to eleven years).
3. The stage of formal operations (eleven years through to adulthood).

Sensorimotor Intelligence (birth to two years)

This developmental period consists of six stages in which the infants organize reflex actions/schemas - like sucking, in order for them to exist in their environment. Sutherland (1992:9) states that the infant's "mental world is geared towards doing (rather than symbolic activity, such as language)." It is characterized by reflex activity, hand-mouth co-ordination, co-ordination of two schemes, object permanence and the beginnings of representation.

Sub-stage (i) Reflexive Actions: (O-1 month)
This stage is characterized by "mere mechanical responses to outside stimuli" according to Piaget (Sutherland,1992:9).

(ii) Primary Circular Reactions: (1-4 months)
The infant is capable of primitive intelligent responses to his environment termed 'circular' by Piaget, due to their repetitive nature. Circular reactions are actions (unlike reflexes) that are repeated by the baby himself because of their pleasantness; i.e.sucking a thumb. A pool of such actions is integral in accommodation processes as new activities become integrated by the domoinant mechanism of this stage - assimilation, an example of circular reactions. It is at this time that one canmark the origins of intent, and the capacity to repeat acts. Here begins "the dawning of memory" (Sutherland, 992:9).

(iii) Secondary Circular Reactions: (4-8 months)
The infant becomes increasingly more interested in his environment. Actions are now deliberately repeated; grabbing toys and putting them in his mouth. Actions are intended now to achieve goals in a secondary circular reaction allowing the baby to extend it's range of possible action thus building schemas. The baby is able to recognise objects - a rattle - as ones that he can shake. Piaget calls this Recognitory assimilation.

(iv) Co-ordination of Secondary Circular Reactions: (8-12 months)
At this stage the infant's behaviour assumes a more purposeful and deliberate, co-ordinated flavour as this time coincides with the onset of crawling and his whole world enlarges. He is not, however, capable of understanding and searching out hidden objects. Object permanence is embyronic, in that he is able to anticipate in play; i.e. the peckaboo game. Schemas are becoming more and more elaborate.

(v) Tertiary Circulary Reactions: (12-18 months)
Sutherland writes of Piaget's most famous experiment used to illustrate the enormous leap forward that the achievement of 'object permanence' brings to the child's cognitive development. In Piagetian terms, this liberates the understanding that a person or object will exist even when it is not able to be seen. Mental representations are a key concept in this theory and linked to'object constancy'. The baby explores its rich environment and actively interact with novel situations, objects and events using trial and error to solve problems.

(vi) Inventive Abilities via Mental Combinations: (18-24 months)
The baby is now able to mentally represent himself. He is able to invent his own play activity and play becomes the most important learning realm. With his toys, he uses symbolic representation to transform objects; i.e. animism or the tendancy to attribute life to inanimate objects. Cognition at this stage moves beyond mere sensorimotor towards preconceptual thought and the genesis of early language, transforming cognitive activity in what Piaget referred to as Post-sensorimotor representational intelligence. Here, the youngster is constructing and recording experiences from a language framework, rather than an action base (Sutherland, 1992).

Operational Intelligence.

It is characterized by pre-conceptual thinking, centration, language acquisition, animism and irreversibility at the pre-operational level. Concrete operations is characterized by reversibility, decentration, classification, ability to order, number seration - large to small and conservation abilities. The term 'operation' is a key concept for Piaget, and is defined as an internalized activity subjected to rules of logic (Lefrancois,1995).

(i) Pre-operational thought:(2-7 years)
The preoperational child is much more capable of understanding his world but markedly different to adults in terms of efficency. This stage is divided into two sub-phases;
Preconceptual thinking: 2-4 years.
This stage is characterized by a lack of ability to classify and regards similar objects as though they are identical in a type of muddled categorization; i.e. all men must be 'Daddy', all animals are 'doggies', all toys are his, one pile of green beads has more than another pile of non-green beads. The preconcepts child cannot hierarchially discriminate between oranges and apples for instance but has a hunger to constantly ask 'what is that?'.
Intuitive thinking: 4-7 years.
Thinking has become more logical and perception plays a striking role now. Piaget's experiments for Conservation indicate the child is able to be easily tricked by dominant and immediate perceptions. 'Egocentrism' or self-centred understanding dominates the thinking in the intuitive child who is unable to understand the point of view of others. Dominant question is 'why?'
(ii) Concrete Operations:(7-11/12 years)
This is the stage of operational thinking characterized by the child's ability to hold ideas in his head simultaneously as problem-solving is going on. Here, Lefrancois (1995:214) says the child begins the transition from "prelogical, egocentric, perception dominated kind of thinking to a more rule-regulated thinking." He learns the acquires the logic of conservation. This is illustrated by the tall and wide beaker experiment so famous in Piagetian theory (also the two pieces of different shaped plasticene).
Piaget terms the notion of Decalage to refer to the 'lag' within different tasks, at different ages of achieving full operations (horizontal). Vertical decalage refers to mastery at different stages of cognitive progress; i.e. sensorimotor etc.

Formal Operations:(11/12- Adulthood)

This stage is characterized by abstract and logical thinking, complex verbal and problem-solving abilities as well as hypothesis formation.
The formal operatioal thinker is a most effective abstract and symbolic thinker. This has implications in education with a wide range of subjects and difficult concepts able to be applied at this stage. Piaget called this hypothetico-deductive whereby the adolescent is able to conceive an idea and use deductive powers to draw conclusions. Sutherland (1992) states that thinking "is no longer limited to reality or personal experience" (p.19). The adolescent is now able to sift through a knowledge field in a process of combinational analysis (Lefrancois,1995).

Piaget's 'Methode Researche' and Theory Criticisms.

Much criticism has been aimed at the methodology and sampling on which Piaget based his empirical data and theoretical stances. He used his own children and those of his Genevian colleagues to develop his huge array of concepts about all childrens' cognition. This very small sample - of academic, high socio-economic status and cultural variables, make for the possiblity that his results/data may be unreliable and, at the very least, unrepresentative. Piaget generalized from a tiny sample base, ignored individual differences and prior learning. His experiments were difficult to replicate and artificial, considered too informal and unscientific.
As well, many have criticized Piaget's pessimistic questioning techniques and feel he tried to catch children out in his experiments; i.e. Donaldson in Sutherland, 1992. The use of more optimal language and help is required compared to the traditional teaching styles of Piaget's era. The same source states that he underestimated children's abilities whilst overestimating adult cognition. He is criticized by Hamlyn (1978) in Sutherland for ignoring the value of social learning - in the mother's arms or with teachers, but not as Piaget suggested, in a social vacuum.
Many critics have found fault with his notion of a lockstep progression through the various stages, commenting that more recent studies have discovered discrepancies in the cognitive abilities within any particular child,and between children. They would dispute Piaget's notion of cognitive 'homogeneity' (Sutherland, 1992).


The monumental work of Jean Piaget has influenced an array of academic fields - education, philosophy and, of course, psychology to this day. He left a mass of data and empirical material which continues to be the springboard for much of the scientific theorizing of contempoary psychologists. The 'clinical method' he pioneered continues to be utilized in some form by many. Others have evolved his theory beyond Formal operations, in adult intelligence theories.


Flavell, J.H. (1996). Piaget's legacy. Psychological Science, 7, 200-203.

Lefrancois, G. (1995). Theories of Human Learning (3rd Ed.). U.S.A.:Brookes /Cole.

Sutherland, P. (1992). Cognitive development today: Piaget and his critics. London: Paul Chapman.

Thomas, R.M. (1996). Comparing theories of child development (4th Ed.). Pacific Grove, CA: Brookes/Cole.


The Jean Piaget Society at
Archives Jean Piaget at

Written by Lesley Olley, of New Plymouth.
You can contact me by emailing me at
Student ID: 07457154.