Piaget's theory of cognitive development Piaget's theory of cognitive development is
a comprehensive theory about the nature and development of human intelligence, first developed
by Swiss developmental psychologist Jean Piaget . It is primarily known as a developmental
stage theory but, in fact, it deals with the nature of knowledge itself and how humans
come gradually to acquire, construct, and use it. To Piaget, cognitive development was
a progressive reorganization of mental processes as a result of biological maturation and environmental
experience. Accordingly, children construct an understanding of the world around them,
then experience discrepancies between what they already know and what they discover in
their environment. Moreover, Piaget claimed the idea that cognitive development is at
the center of human organism, and language is contingent on cognitive development. Below
is a short description of Piaget's views about the nature of intelligence, followed by a
description of the stages through which it develops until maturity.
Nature of intelligence: operative and figurative Piaget noted reality in the sense of as a
dynamic system of continuous change and, as such, is defined in reference to the two conditions
that define dynamic systems. Specifically, he argued that reality involves transformations
and states. Transformations refer to all manners of changes that a thing or person can undergo.
States refer to the conditions or the appearances in which things or persons can be found between
transformations. For example, there might be changes in shape or form (for instance,
liquids are reshaped as they are transferred from one vessel to another, humans change
in their characteristics as they grow older), in size (for example, a series of coins on
a table might be placed close to each other or far apart), or in placement or location
in space and time (e.g., various objects or persons might be found at one place at one
time and at a different place at another time). Thus, Piaget argued, if human intelligence
is to be adaptive, it must have functions to represent both the transformational and
the static aspects of reality. He proposed that operative intelligence is responsible
for the representation and manipulation of the dynamic or transformational aspects of
reality, and that figurative intelligence is responsible for the representation of the
static aspects of reality. Operative intelligence is the active aspect
of intelligence. It involves all actions, overt or covert, undertaken in order to follow,
recover, or anticipate the transformations of the objects or persons of interest. Figurative
intelligence is the more or less static aspect of intelligence, involving all means of representation
used to retain in mind the states (i.e., successive forms, shapes, or locations) that intervene
between transformations. That is, it involves perception, imitation, mental imagery, drawing,
and language. Therefore, the figurative aspects of intelligence derive their meaning from
the operative aspects of intelligence, because states cannot exist independently of the transformations
that interconnect them. Piaget stated that the figurative or the representational aspects
of intelligence are subservient to its operative and dynamic aspects, and therefore, that understanding
essentially derives from the operative aspect of intelligence.
At any time, operative intelligence frames how the world is understood and it changes
if understanding is not successful. Piaget stated that this process of understanding
and change involves two basic functions: assimilation and accommodation.
Assimilation and accommodation Through his study of the field of education,
Piaget focused on two processes, which he named assimilation and accommodation. Assimilation
describes how humans perceive and adapt to new information. It is the process of fitting
new information into pre-existing cognitive schemas. Assimilation occurs when humans are
faced with new or unfamiliar information and refer to previously learned information in
order to make sense of it. Unlike it, accommodation is the process of taking new information in
one's environment and altering pre-existing schemas in order to fit in the new information.
Through a series of stages, Piaget explains the ways in which characteristics are constructed
that lead to specific types of thinking. This chart is called cognitive development. To
Piaget, assimilation is integrating external elements into structures of lives or environments,
or those we could have through experience. It is through assimilation that accommodation
is derived. Accommodation is imperative because it is how people will continue to interpret
new concepts, schemas, frameworks, and more. Assimilation is different from accommodation
by how it relates to the inner organism due to the environment. Piaget believes that the
human brain has been programmed through evolution to bring equilibrium, which is what Piaget
believes ultimately influences structures by the internal and external processes through
assimilation and accommodation. Piaget's understanding is that these two functions
cannot exist without the other. To assimilate an object into an existing mental schema,
one first needs to take into account or accommodate to the particularities of this object to a
certain extent. For instance, to recognize (assimilate) an apple as an apple, one must
first focus (accommodate) on the contour of this object. To do this, one needs to roughly
recognize the size of the object. Development increases the balance, or equilibration, between
these two functions. When in balance with each other, assimilation and accommodation
generate mental schemas of the operative intelligence. When one function dominates over the other,
they generate representations which belong to figurative intelligence.
Sensorimotor stage The sensorimotor stage is the first of the
four stages in cognitive development which "extends from birth to the acquisition of
language". In this stage, infants progressively construct knowledge and understanding of the
world by coordinating experiences (such as vision and hearing) with physical interactions
with objects (such as grasping, sucking, and stepping). Infants gain knowledge of the world
from these physical actions they perform within it. They progress from reflexive, instinctual
action at birth to the beginning of symbolic thought toward the end of the stage.
The child learns that he/she is separate from the environment and that aspects of the environment
continue to exist, even though they may be outside the reach of the child's senses. In
this stage, according to Piaget, the development of object permanence is one of the most important
accomplishments. Object permanence is a child’s understanding that objects continue to exist
even though they cannot be seen or heard. Piaget divided the sensorimotor stage into
six sub-stages". By the end of the sensorimotor period, the
child sees objects as both separate from the self, and permanent.
Pre-operational stage Piaget's second stage, the pre-operational
stage, starts when the child begins to learn to speak at age two and lasts up until the
age of seven. During the Pre-operational Stage of cognitive development, Piaget noted that
children do not yet understand concrete logic and cannot mentally manipulate information.
Children’s increase in playing and pretending takes place in this stage. However, the child
still has trouble seeing things from different points of view. The children's play is mainly
categorized by symbolic play and manipulating symbols. Such play is demonstrated by the
idea of checkers being snacks, pieces of paper being plates, and a box being a table. Their
observations of symbols exemplifies the idea of play with the absence of the actual objects
involved. By observing sequences of play, Piaget was able to demonstrate that, towards
the end of the second year, a qualitatively new kind of psychological functioning occurs,
known as the Pre-operational Stage. The pre-operational stage is sparse and logically
inadequate in regard to mental operations. The child is able to form stable concepts
as well as magical beliefs. The child, however, is still not able to perform operations, which
are tasks that the child can do mentally, rather than physically. Thinking in this stage
is still egocentric, meaning the child has difficulty seeing the viewpoint of others.
The Pre-operational Stage is split into two substages: the symbolic function substage,
and the intuitive thought substage. The symbolic function substage is when children are able
to understand, represent, remember, and picture objects in their mind without having the object
in front of them. The intuitive thought substage is when children tend to propose the questions
of "why?" and "how come?" This stage is when children want the knowledge of knowing everything.
Symbolic function substage At about two to four years of age, children
cannot yet manipulate and transform information in a logical way. However, they now can think
in images and symbols. Other examples of mental abilities are language and pretend play. Symbolic
play is when children develop imaginary friends or role-play with friends. Children’s play
becomes more social and they assign roles to each other. Some examples of symbolic play
include playing house, or having a tea party. Interestingly, the type of symbolic play in
which children engage is connected with their level of creativity and ability to connect
with others. Additionally, the quality of their symbolic play can have consequences
on their later development. For example, young children whose symbolic play is of a violent
nature tend to exhibit less prosocial behavior and are more likely to display antisocial
tendencies in later years. In this stage, there are still limitations,
such as egocentrism and precausal thinking. Egocentrism occurs when a child is unable
to distinguish between their own perspective and that of another person. Children tend
to stick to their own viewpoint, rather than consider the view of others. Indeed, they
are not even aware that such a concept as "different viewpoints" exists. Egocentrism
can be seen in an experiment performed by Piaget and Swiss developmental psychologist
Bärbel Inhelder, known as the three-mountain problem. In this experiment, three views of
a mountain are shown to the child, who is asked what a traveling doll would see at the
various angles. The child will consistently describe what they can see from the position
from which they are seated, regardless of from what angle they are asked to take the
doll's perspective. Egocentrism would also cause a child to believe, "I like Sesame Street,
so Daddy must like Sesame Street, too". Similar to preoperational children's egocentric
thinking is their structuring of a cause and effect relationships. Piaget coined the term
"precausal thinking" to describe the way in which preoperational children use their own
existing ideas or views, like in egocentrism, to explain cause-and-effect relationships.
Three main concepts of causality as displayed by children in the preoperational stage include:
animism, artificialism and transductive reasoning. Animism is the belief that inanimate objects
are capable of actions and have lifelike qualities. An example could be a child believing that
the sidewalk was mad and made them fall down, or that the stars twinkle in the sky because
they are happy. Artificialism refers to the belief that environmental characteristics
can be attributed to human actions or interventions. For example, a child might say that it is
windy outside because someone is blowing very hard, or the clouds are white because someone
painted them that color. Finally, precausal thinking is categorized by transductive reasoning.
Transductive reasoning is when a child fails to understand the true relationships between
cause and effect. Unlike deductive or inductive reasoning (general to specific, or specific
to general), transductive reasoning refers to when a child reasons from specific to specific,
drawing a relationship between two separate events that are otherwise unrelated. For example,
if a child hears the dog bark and then a balloon popped, the child would conclude that because
the dog barked, the balloon popped. Intuitive thought substage
At between about the ages of 4 and 7, children tend to become very curious and ask many questions,
beginning the use of primitive reasoning. There is an emergence in the interest of reasoning
and wanting to know why things are the way they are. Piaget called it the "intuitive
substage" because children realize they have a vast amount of knowledge, but they are unaware
of how they acquired it. Centration, conservation, irreversibility, class inclusion, and transitive
inference are all characteristics of preoperative thought.
Centration is the act of focusing all attention on one characteristic or dimension of a situation,
whilst disregarding all others. Conservation is the awareness that altering a substance's
appearance does not change its basic properties. Children at this stage are unaware of conservation
and exhibit centration. Both centration and conservation can be more easily understood
once familiarized with Piaget's most famous experimental task.
In this task, a child is presented with two identical beakers containing the same amount
of liquid. The child usually notes that the beakers do contain the same amount of liquid.
When one of the beakers is poured into a taller and thinner container, children who are younger
than seven or eight years old typically say that the two beakers no longer contain the
same amount of liquid, and that the taller container holds the larger quantity (centration),
without taking into consideration the fact that both beakers were previously noted to
contain the same amount of liquid. Due to superficial changes, the child was unable
to comprehend that the properties of the substances continued to remain the same (conservation).
Irreversibility is a concept developed in this stage which is closely related to the
ideas of centration and conservation. Irreversibility refers to when children are unable to mentally
reverse a sequence of events. In the same beaker situation, the child does not realize
that, if the sequence of events was reversed and the water from the tall beaker was poured
back into its original beaker, then the same amount of water would exist. Another example
of children's reliance on visual representations is their misunderstanding of "less than" or
"more than". When two rows containing equal amounts of blocks are placed in front of a
child, one row spread farther apart than the other, the child will think that the row spread
farther contains more blocks. Class inclusion refers to a kind of conceptual
thinking that children in the preoperational stage cannot yet grasp. Children’s inability
to focus on two aspects of a situation at once inhibits them from understanding the
principle that one category or class can contain several different subcategories or classes.
For example, a four-year-old girl may be shown a picture of eight dogs and three cats. The
girl knows what cats and dogs are, and she is aware that they are both animals. However,
when asked, “Are there more dogs or animals?” she is likely to answer “more dogs”. This
is due to her difficulty focusing on the two subclasses and the larger class all at the
same time. She may have been able to view the dogs as dogs or animals, but struggled
when trying to classify them as both, simultaneously. Similar to this is concept relating to intuitive
thought, known as "transitive inference". Transitive inference is using previous knowledge
to determine the missing piece, using basic logic. Children in the preoperational stage
lack this logic. An example of transitive inference would be when a child is presented
with the information "A" is greater than "B" and "B" is greater than "C". This child may
have difficulty here understanding that "A" is also greater than "C".
Concrete operational stage The concrete operational stage is the third
of four stages from Piaget's theory of cognitive development. This stage, which follows the
preoperational stage, occurs between the ages of seven and 11 years, and is characterized
by the appropriate use of logic. During this stage, a child's thought processes become
more mature and "adult like". They start solving problems in a more logical fashion. Abstract,
hypothetical thinking has not yet developed, and children can only solve problems that
apply to concrete events or objects. Piaget determined that children are able to incorporate
inductive reasoning. Inductive reasoning involves drawing inferences from observations in order
to make a generalization. In contrast, children struggle with deductive reasoning, which involves
using a generalized principle in order to try to predict the outcome of an event. Children
in this stage commonly experience difficulties with figuring out logic in their heads. For
example, a child will understand that "A is more than B" and "B is more than C". However,
when asked "is A more than C?", the child might not be able to logically figure the
question out in their heads. Milestones of the concrete operational stage
The primary milestones of a child's concrete operational stage are:
Ability to distinguish between their own thoughts and the thoughts of others: children recognize
that their thoughts and perceptions may be different from those around them.
Increased classification skills: children are able to classify objects by their number,
mass, and weight. Ability to think logically about objects and
events. Ability to fluently perform mathematical problems
in both addition and subtraction. Important processes
Important processes during the concrete operational stage include:
Classification: the ability to name and identify sets of objects according to appearance, size
or other characteristic, including the idea that one set of objects can include another.
Hierarchical classification refers to the ability to sort objects into classes and subclasses
based on similarities and differences among groups.
Conservation: the understanding that, although an object’s appearance changes, it still
stays the same in quantity. Redistributing an object does not affect its mass, number,
or volume. For example, a child understands that when you pour a liquid into a different-shaped
glass, the amount of liquid stays the same. Decentering: the child now takes into account
multiple aspects of a problem to solve it. For example, the child will no longer perceive
an exceptionally wide but short cup to contain less than a normally wide, taller cup.
Reversibility: the child now understands that numbers or objects can be changed and then
returned to their original state. For example, a child understands that his or her favorite
ball that deflates is not gone and can be filled with air and put back into play again.
Another example would be when the child realizes that a ball of clay, once flattened, can be
made into a ball of clay again. Seriation: the ability to sort objects in
an order according to size, shape, or any other characteristic. For example, different-shaded
objects may make a color gradient. Transitivity: transitivity, which refers to
the ability to mentally sort objects and recognize relationships among various things in a serial
order. For example, when told to put away his books according to height, the child recognizes
that he starts with placing the tallest one on one end of the bookshelf and the shortest
at the other end. Two other important processes in the concrete
operational stage are the elimination of egocentrism and logic.
Egocentrism is the inability to consider or understand a perspective other than one's
own. During this stage, the child acquires the ability to view things from another individual's
perspective, even if they think that perspective is incorrect. For instance, show a child a
comic in which Jane puts a doll under a box, leaves the room, and then Melissa moves the
doll to a drawer, and Jane comes back. A child in the concrete operations stage will say
that Jane will still think it's under the box even though the child knows it is in the
drawer. (See also False-belief task.) Children in this stage can, however, only
solve problems that apply to actual (concrete) objects or events, and not abstract concepts
or hypothetical tasks. Understanding and knowing how to use full common sense has not yet been
completely adapted. Piaget determined that children in the concrete
operational stage were able to incorporate inductive logic. On the other hand, children
at this age have difficulty using deductive logic, which involves using a general principle
to predict the outcome of a specific event. This includes mental reversibility. An example
of this is being able to reverse the order of relationships between mental categories.
For example, a child might be able to recognize that his or her dog is a Labrador, that a
Labrador is a dog, and that a dog is an animal, and draw conclusions from the information
available, as well as apply all these processes to hypothetical situations.
The abstract quality of the adolescent's thought at the formal operational level is evident
in the adolescent's verbal problem solving ability. The logical quality of the adolescent's
thought is when children are more likely to solve problems in a trial-and-error fashion.
Adolescents begin to think more as a scientist thinks, devising plans to solve problems and
systematically test opinions. They use hypothetical-deductive reasoning, which means that they develop hypotheses
or best guesses, and systematically deduce, or conclude, which is the best path to follow
in solving the problem. During this stage the adolescent is able to understand such
things as love, "shades of gray," logical proofs and values. During this stage the young
person begins to entertain possibilities for the future and is fascinated with what they
can be. Adolescents also are changing cognitively
by the way that they think about social matters. Adolescent egocentrism governs the way that
adolescents think about social matters, and is the heightened self-consciousness in them
as they are, which is reflected in their sense of personal uniqueness and invincibility.
Adolescent egocentrism can be dissected into two types of social thinking, imaginary audience
that involves attention-getting behavior, and personal fable, which involves an adolescent's
sense of personal uniqueness and invincibility. These two types of social thinking begin to
affect a child's egocentrism in the concrete stage. However, it carries over to the formal
operational stage when they are then faced with abstract thought and fully logical thinking.
Testing for concrete operations Piagetian tests are well known and practised
to test for concrete operations. The most prevalent tests are those for conservation.
There are some important aspects that the experimenter must take into account when performing
experiments with these children. One example of an experiment for testing conservation
is an experimenter will have two glasses that are the same size, fill them to the same level
with liquid, which the child will acknowledge is the same. Then, the experimenter will pour
the liquid from one of the small glasses into a tall, thin glass. The experimenter will
then ask the child if the taller glass has more liquid, less liquid, or the same amount
of liquid. The child will then give his answer. The experimenter will ask the child why he
gave his answer, or why he thinks that is. Justification: After the child has answered
the question being posed, the experimenter must ask why the child gave that answer. This
is important because the answers they give can help the experimenter to assess the child's
developmental age. Number of times asking: Some argue that if
a child is asked if the amount of liquid in the first set of glasses is equal then, after
pouring the water into the taller glass, the experimenter asks again about the amount of
liquid, the children will start to doubt their original answer. They may start to think that
the original levels were not equal, which will influence their second answer.
Word Choice: The phrasing that the experimenter uses may affect how the child answers. If,
in the liquid and glass example, the experimenter asks, "Which of these glasses has more liquid?",
the child may think that his thoughts of them being the same is wrong because the adult
is saying that one must have more. Alternatively, if the experimenter asks, "Are these equal?",
then the child is more likely to say that they are, because the experimenter is implying
that they are. Formal operational stage
The final stage is known as the formal operational stage (adolescence and into adulthood, roughly
ages 11 to approximately 15-20): Intelligence is demonstrated through the logical use of
symbols related to abstract concepts. At this point, the person is capable of hypothetical
and deductive reasoning. During this time, people develop the ability to think about
abstract concepts. Piaget stated that "hypothetico-deductive
reasoning" becomes important during the formal operational stage. This type of thinking involves
hypothetical situations and is often required in science and mathematics.
Abstract thought emerges during the formal operational stage. Children tend to think
very concretely and specifically in earlier stages, and begin to consider possible outcomes
and consequences of actions. Metacognition, the capacity for "thinking
about thinking" that allows adolescents and adults to reason about their thought processes
and monitor them. Problem-solving is demonstrated when children
use trial-and-error to solve problems. The ability to systematically solve a problem
in a logical and methodical way emerges. "However, research has shown that not all
persons in all cultures reach formal operations, and most people do not use formal operations
in all aspects of their lives". The stages and causation
Piaget sees children’s conception of causation as a march from "primitive" conceptions of
cause to those of a more scientific, rigorous, and mechanical nature. These primitive concepts
are characterized as supernatural, with a decidedly nonnatural or nonmechanical tone.
Piaget has as his most basic assumption that babies are phenomenists. That is, their knowledge
"consists of assimilating things to schemas" from their own action such that they appear,
from the child’s point of view, "to have qualities which, in fact, stem from the organism".
Consequently, these "subjective conceptions," so prevalent during Piaget’s first stage
of development, are dashed upon discovering deeper empirical truths.
Piaget gives the example of a child believing that the moon and stars follow him on a night
walk. Upon learning that such is the case for his friends, he must separate his self
from the object, resulting in a theory that the moon is immobile, or moves independently
of other agents. The second stage, from around three to eight
years of age, is characterized by a mix of this type of magical, animistic, or “nonnatural”
conceptions of causation and mechanical or "naturalistic" causation. This conjunction
of natural and nonnatural causal explanations supposedly stems from experience itself, though
Piaget does not make much of an attempt to describe the nature of the differences in
conception. In his interviews with children, he asked questions specifically about natural
phenomena, such as: "What makes clouds move?", "What makes the stars move?", "Why do rivers
flow?" The nature of all the answers given, Piaget says, are such that these objects must
perform their actions to "fulfill their obligations towards men". He calls this "moral explanation".
Practical applications Parents can use Piaget's theory when deciding
how to determine what to buy in order to support their child's growth. Teachers can also use
Piaget's theory, for instance, when discussing whether the syllabus subjects are suitable
for the level of students or not. For example, recent studies have shown that children in
the same grade and of the same age perform differentially on tasks measuring basic addition
and subtraction fluency. While children in the preoperational and concrete operational
levels of cognitive development perform combined arithmetic operations (such as addition and
subtraction) with similar accuracy, children in the concrete operational level of cognitive
development have been able to perform both addition problems and subtraction problems
with overall greater fluency. The ability to perform mathematical operations
fluently indicates a level of skill mastery and a readiness to learn more advanced mathematical
problems. Teachers who work with children in both the preoperational and the concrete
operational levels of cognitive development should adopt suitable academic expectations
with regard to children's cognitive developmental abilities. The need for educators to individualize
and adopt appropriate academic expectations appears to be most relevant for children at
the first-grade level. Postulated physical mechanisms underlying
"schemes" and stages In 1967, Piaget considered the possibility
of RNA molecules as likely embodiments of his still-abstract "schemes" (which he promoted
as units of action)—though he did not come to any firm conclusion. At that time, due
to work such as that of Swedish biochemist Holger Hydén, RNA concentrations had, indeed,
been shown to correlate with learning, so the idea was quite plausible.
However, by the time of Piaget's death in 1980, this notion had lost favour. One main
problem was over the protein which, it was assumed, such RNA would necessarily produce,
and that did not fit in with observation. It was determined that only about 3% of RNA
does code for protein (Mattick, 2001, 2003, 2004). Hence, most of the remaining 97% (the
"ncRNA") could theoretically be available to serve as Piagetian schemes (or other regulatory
roles now under investigation). The issue has not yet been resolved experimentally,
but its theoretical aspects were reviewed in 2008 — then developed further from the
viewpoints of biophysics and epistemology. Meanwhile, this RNA-based approach also unexpectedly
offered explanations for various other bio-mysteries, thus providing some measure of corroboration.
Relation to psychometric theories of intelligence Piaget designed a number of tasks to verify
hypotheses arising from his theory. The tasks were not intended to measure individual differences,
and they have no equivalent in psychometric intelligence tests. Notwithstanding the different
research traditions in which psychometric tests and Piagetian tasks were developed,
the correlations between the two types of measures have been found to be consistently
positive and generally moderate in magnitude. A common general factor underlies them. It
has been shown that it is possible to construct a battery consisting of Piagetian tasks that
is as good a measure of general intelligence as standard IQ tests.
Challenges to Piagetian stage theory Piagetians' accounts of development have been
challenged on several grounds. First, as Piaget himself noted, development does not always
progress in the smooth manner his theory seems to predict. "Decalage," or unpredicted gaps
in the developmental progression, suggest that the stage model is, at best, a useful
approximation. Furthermore, studies have found that children may be able to learn concepts
supposedly represented in more advanced stages with relative ease. More broadly, Piaget's
theory is "domain general," predicting that cognitive maturation occurs concurrently across
different domains of knowledge (such as mathematics, logic, and understanding of physics or language).
During the 1980s and 1990s, cognitive developmentalists were influenced by "neo-nativist" and evolutionary
psychology ideas. These ideas de-emphasized domain general theories and emphasized domain
specificity or modularity of mind. Modularity implies that different cognitive faculties
may be largely independent of one another, and thus develop according to quite different
timetables. In this vein, some cognitive developmentalists argued that, rather than being domain general
learners, children come equipped with domain specific theories, sometimes referred to as
"core knowledge," which allows them to break into learning within that domain. For example,
even young infants appear to be sensitive to some predictable regularities in the movement
and interactions of objects (for example, that one object cannot pass through another),
or in human behavior (for example, that a hand repeatedly reaching for an object has
that object, not just a particular path of motion), as it becomes the building block
of which more elaborate knowledge is constructed. More recent work has strongly challenged some
of the basic presumptions of the "core knowledge" school, and revised ideas of domain generality—but
from a newer dynamic systems approach, not from a revised Piagetian perspective. Dynamic
systems approaches harken to modern neuroscientific research that was not available to Piaget
when he was constructing his theory. One important finding is that domain-specific knowledge
is constructed as children develop and integrate knowledge. This suggests more of a "smooth
integration" of learning and development than either Piaget, or his neo-nativist critics,
had envisioned. Additionally, some psychologists, such as Lev Vygotsky and Jerome Bruner, thought
differently from Piaget, suggesting that language was more important than Piaget implied.
Post-Piagetian and Neo-Piagetian stages In recent years, several scholars attempted
to address concerns with Piaget's theory by developing new theories and models that can
accommodate evidence which violates Piagetian predictions and postulates.
The neo-Piagetian theories of cognitive development, advanced by Case, Demetriou, Halford, Fischer,
Michael Commons, and Pascual-Leone, attempted to integrate Piaget's theory with cognitive
and differential theories of cognitive organization and development. Their aim was to better account
for the cognitive factors of development and for intra-individual and inter-individual
differences in cognitive development. They suggested that development along Piaget's
stages is due to increasing working memory capacity and processing efficiency. Moreover,
Demetriou´s theory ascribes an important role to hypercognitive processes of self-recording,
self-monitoring, and self-regulation, and it recognizes the operation of several relatively
autonomous domains of thought (Demetriou, 1998; Demetriou, Mouyi, Spanoudis, 2010).
Piaget's theory stops at the formal operational stage, but other researchers have observed
the thinking of adults is more nuanced than formal operational thought. This stage has
been named postformal thought. Postformal stages have been proposed. Kurt Fischer suggested
two, and Michael Commons presented evidence for four postformal stages: systematic, metasystematic,
paradigmatic, and cross-paradigmatic. (Commons & Richards, 2003; Oliver, 2004) There are
many scholars, however, who have critizized "postformal thinking," because the concept
lacks both theoretical and empirical verification. The term "integrative thinking" has been suggested
for use instead. A "sentential" stage, said to occur before
the early preoperational stage, has been proposed by Fischer, Biggs and Biggs, Commons, and
Richards. Searching for a micro-physiological basis
for human mental capacity, Traill (1978, Section C5.4; - 1999, Section 8.4 ) proposed that
there may be "pre-sensorimotor" stages ("M−1L", "M−2L", … … ), which are developed in
the womb and/or transmitted genetically. Jerome Bruner has expressed views on cognitive
development. Michael Lamport Commons proposed the model
of hierarchical complexity. Kieran Egan has proposed stages of understanding.
Lawrence Kohlberg developed stages of moral development.
Andreas Demetriou has expressed Neo-Piagetian theories of cognitive development.
Loevinger's stages of ego development Ken Wilber has incorporated Piaget's theory
in his multidisciplinary field of Integral Theory.
The process of initiation is a modification of Piaget's theory integrating Abraham Maslow's
concept of self-actualization.