Piaget and Vygotsky


Why Developmental Theories?

  • Provide a framework for understanding important phenomena - ties things togrther, provides structure and coherence.
  • Raise crucial questions about human nature - predictions.
  • Motivate new research studies that lead to a better understanding of children.
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Why don't we just have One Theory ?

Because child development is a complex and varied process, no single theory accounts for all of it

  • Theories of cognitive and social development, for example, focus on different capabilities.

Multiple theories allow a broader appreciation of cognitive development than any one theory does by itself.

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Piaget (a rationalist) - from within

Locke (an empiricist) - from without

Piaget (a constructionist) - from the interaction between the child and the environment

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Jean Piaget (1896 - 1980)

  • Most widely known and influential theorist of child development.
  • His theory is often labelled constructivist because it depicts children as constructing knowledge for themselves.
  • Piagetian children are seen as "little scientists":
    - learning many important lessons on their own
    - intrinsically motivated to learn
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Piaget's Theory

Four characteristics:

  • Constructionist
  • Stage theory
  • Invariant sequence
  • Universal

Development involves continuities and discontinuities.

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Sources of Continuity

Three proceses work together from birth to propel development forward:

  • Assimilation - The process by which people translate incoming information into a form they can understand. Infant learns about how objects behave and generalises to other objects, e.g. the rattle.
  • Accommodation - The process by which people adapt current knowledge structures in response to new experiences. Infants' theories about the world can be contradicted (e.g. "things come closer when I pull them") so infants must adjust their theory to incorporate this new information ("Inanimate objects come closer when I pull them")
  • Equilibration - The process by which people balance assimilation and accommodation to create stable understanding.
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  • In addition to continuous aspects of development, most famous part of Piaget's theory concerns discontinuities.
  • Hierarchial stages
  • Central properties:
    - qualitative change (e.g. morality - behaviour vs. intent)
    - broad applicability
    - brief transitions
    - invariant sequence
  • Piaget's theory is considered a discontinuous view of development because of his distinct, hierarchical stages.
  • Hypothesised that children progress through four stages of cognitive development, each building on the previous one.
    - Sensorimotor
    - Pre-operational
    - Concrete operational
    - Formal operational
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Stage 1 - Sensorimotor Stage (birth - 2 years)

Infants get to know the world through their senses and through their actions.

Critical cognitive achievements and errors include:

  • Object permanence - the knowledge that objects continue to exist even when they are out of view, typically emerges by about 8 months.
  • After attaining object permanence, children make the A-Not-B-error (the tendency to reach to where objects were found before, rather than where they were last hidden) until about 12 months.
  • Children start to form enduring mental representations by stage end - the first sign is deferred imitation (the repetition of other people's behaviour a substantial time after it occurred).
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Piaget's A-Not-B Task

  • The infant has already found the toy under the left cloth (A) on a number of trials.
  • When the toy is hidden under the cloth on the left (B) in front of their eyes, the infant returns to location (A).
  • Suggests that the child mentally represents the object after it has disappeared from view, but this representation is fragile.
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Stage 2 - Pre-Operational Stage (2-7 years)

Toddlers and young children start to rely on internal representations of the world based on language and mental imagery.

A mix of impressive cognitive acquisitions and equally impressive limitations:

  • A notable acquisition is symbolic representation, the use of one object to stand for another, which makes a variety of new behaviours possible. (e.g. using a banana as a phone)
  • A major limitation is egocentrism, the tendency to perceive the world solely from one's own point of view. (Piaget & Inhelder's three-mountains task - children could only describe it from their own point of view)
  • Pre-Operational children also make conservation errors, where they incorrectly believe that merely changing the appearance of objects can change their quantity (e.g. pouring one of two glasses of water with the same amount into a taller glass).
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Why do Children make Conservation Errors?

"Centration" - focus on one perceptually salient aspect of the stimulus and ignore the other stimulus dimensions

  • e.g. height of the liquid, but not the width of the glass
  • e.g. the balance scale.
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Stage 3 - Concrete Operational Stage (7 - 12 years

Children begin to reason logically about the world.

They can solve conservation problems, but their successful reasoning is largely limited to concrete situations.

Thinking systematically remains difficult.

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Inhelder and Piaget's Pendulum Problem

  • The task is to compare the motions of longer and shorter strings, with lighter and heavier weights attached, in order to determine the influence of weight, string length, and dropping point on the time it takes for the pendulum to swing back and forth.
  • Children below age 12 usually perform unsystematic experiments and draw incorrect conclusions.
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Stage 4 - Formal Operational Stage (12+ years)

  • Cognitive development culminates in the ability to think abstractly and to reason hypothetically.
  • Individuals can imagine alternative worlds and reason systematically about all possible outcomes of a situation.
  • Piaget believed that the attainment of the formal operational stage, in contrast to the other stages, is not universal. Instead it depends on the environment and quality of education, and attainment os more common in industrialised societies.
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Critique of Piaget's Theory

Although Piaget's theory remains highly influential, some weaknesses are now apparent.

  • The stage model depicts children's thinking as being more consistent than it is (but e.g. conservation of number vs. solid - quantity).
  • Infants and young children are more cognitively competent than Piaget recognised.
  • Piaget's theory understates the contribution of the social world to cognitive development (what about the role of other people in the child's development?)
  • Piaget's theory is vague about the cognitive processes that give rise to children's thinking and about the mechanisms that produce cognitive growth (what are the processes that lead children to think in a particular way? Piaget didn't really elaborate).
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Interpreting Adult Intentions

Light, Buckingham and Robbins replicated the water conservation study but provided a reason for why the cups had to be changed (a crack in the cup). By providing a clear reason for making the change of glass, more children pass this version of the task.

McGarrigle and Donaldson tested 80 4-6 year olds on a task in counting the number of counters when spread apart. 72% correct responses in teddy condition where transformations occured 'accidentally' (a naughty teddy spoils the game) compared to 34% in control conditions where transformations occurred in the usual way via an adult.

Why do these manipulations work? Because the child assumes if an adult does something it must mean something has changed.

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Lee Vygotsky (1896-1934)

  • Parent of sociocultural approach to child development.
  • His theory presents children as social beings, intertwined with other people who are eager to help them gain skills and understanding.
  • His work didn't reach the attention of Western psychologists until the 1960s.
  • Subsequent psychologists (such as Jerome Bruner) extended and developed Vygotsky's work by adding interpretations.
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Sociocultural Approaches

  • Focus on the contribution of other people and the surrounding culture to children's development.
  • Emphasise guided participation, a process in which more knowledgeable individuals organise activities in ways that allow less knowledgeable people to engage in them at a higher level than they could manage on their own.
  • Present interactions as occuring in a broader sociocultural context that includes cultural tools, the innumerable products of human ingenuity that enhance thinking.
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Vygotsky's Theory

  • Piaget considered children to be "little scientists" trying to understand the world on their own.
  • Vygotsky portrayed them as social beings, intertwined with other people who are eager to help them gain skills and understanding that they need to interact successfully with the world.
  • Children are viewed as social beings, shaped by and shaping their cultural contexts. Children develop and learn by interacting with other members of their society.
  • It sees development as continuous, with change as quantitative rather than qualitative.
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Mental Functions

Vygotsky distinguished between two levels of mental functioning:

  • Lower mental functions are regarded as elementary mental abilities closely tied to biological processes that are innate and involuntary, and involve simple perception, memory and responding directly to the environment.
  • Higher mental functions are regarded as consciously controlled transformations of lower functions that are developed through cultural mediation, and involve voluntary attention, conceptual thought and logical planning.
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  • Higher mental functions develop through cultural mediationthe transmission of knowledge through social interactions with other people.
  • Interactions allow a child to learn the cultural tools (also known as cultural artefacts) of their society
    - These include language, values, skills and other symbolic systems that represent the shared knowledge of a culture.
  • Eventually a child understands a cultural tool and can use it independently (i.e. without the help of social interaction); this process is known as internalisation.
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Children's Private Speech

Piaget called this "egocentric speech".

Vygotsky viewed it as foundation for all higher cognitive processes. Indeed that language and thought are integrally related:

  • Helps guide behaviour.
  • Used more when tasks are difficult, after errors, or when confused.
  • Gradually becomes more silent.
  • Children with learning and behavioural problems use it for longer.
  • External-to-internal develops with age, but also experience.
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Behaviour Regulation

  • 1) Children's behaviour is controlled by other people's statements - parent/guardian instruction.
  • 2) Children's behaviour is controlled by their own private speech - most prevalent between 4-6 years, though also common in older children and adults during complex tasks.
  • 3) Children's behaviour is controlled by internalised private speech - speech "goes underground" and becomes thought. The transition into silent thought often involves whispers and lip movements.
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Teachers and Learners

  • Adults teach the young facts, skills, values and traditions - this happens in every human society and makes culture possible.
  • The inclination to teach and learn are uniquely human (Tomasello).
    - It emerges very early; even a 2-year-old will spontaneously point to something interesting to attract other people's attention.
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Products of Culture

  • The content that children learn varies greatly from culture to culture and these differences shape children's thinking accordingly.
  • For example, American and Chinese students were given two problems to solve (Chen et al.)
    - Problem 1 could be solved by making an analogy to the Hansel and Gretel fairytale: American students far outperformed Chinese students.
    - Problem 2 could be solved by making an analogy to a Chinese fairytale: Chinese students far outperformed American students.
  • The English and Chinese counting systems both use the decade followed by a digit but English numbers 11-19 do not follow this pattern - this affects brick counting methods. (Miura et al.)
  • Sociocultural theorists believe that change occurs through social interaction.
  • Although cultural content varies, the processes that produce development are the same in all societies
    - Intersubjectivity
    - Zone of Proximal Development
    - Social Scaffolding
    - Guided participation
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  • The mutual understanding that people share during communication - serves as the foundation of human cognitive development.
  • Joint attention: A process in which social partners intentionally focus on a common referent in the external environment.
  • Social referencing: The tendency to look to social partners for guidance about how to respond to unfamiliar or threatening events.
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Joint Attention

  • Joint attention lies at the heart of intersubjectivity and is important for children's abilities to learn from others.
  • Infants between 9 - 15 months can increasingly follow the gaze of their social partners and adjust where they look if their partner's gaze turns towards a new object (Adamson et al.)
  • The younger the age at which infants begin to show joint attention, the faster their subsequent language development (Carpenter et al.)
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Zone of Proximal Development

  • Refers to the range of performance betwee what children can do unsupported and what they can do with optimal support.
  • Vygotsky: "What a child can do with assistance today she will be able to do by herself tomorrow"
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Social Scaffolding

  • A process in which more competent people provide a temporary framework that supports children's thinking at a higher level than children could manage on their own (into the ZPD).
  • The quality of scaffolding that people provide tends to increase as people become older and gain experience.
    - Adults and older children provide higher quality social scaffolding through guided participation than peers do through play.
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Guided Participation

More knowledgeable individuals can organise activities in ways that allow children to engage in them in a kind of cultural apprenticeship (Rogoff)

  • For example, Mayan girls are taught to weave by their mothers with increasingly responsibility and complexity as they get older.
  • Very young girls mainly observe their mothers and other adult women weaving on a loom.
  • By age 5, they plait long leaves on a play loom.
  • By age 7, they weave with help on real looms.
  • By age 9, they weave simple items alone.
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Play with peers is one way that children can stretch their performance into the ZPD.

Playing games involves rules and roles, allowing the child to learn how to:

  • Separate ideas from objects (conceptual development)
  • Self-regulate behaviour (social development)
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Vygotsky vs. Piaget

  • Vygotsky and Piaget were aware of each other's work (though not at the same timeL it was many years after Vygotsky's death that Piaget learned of his work).
  • Although subsequent psychologists have developed different variants of both theories, there is a traditional distinction between Vygotskian and Piagetian views.
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Comparing Vygotsky and Piaget


  • Piaget: Language develops together with other skills, mirroring other skills.
  • Vygotsky: Language does not just reflect the child's skills, it can work as a tool for the child.

Early Speech

  • Piaget: early speech is egocentric, but with development it can function for social communication (inner to outer).
  • Vygotsky: early speech is adaptive to social interaction, and once it is mastered it is then internalised (outer to inner).


  • Piaget: The content and level of teaching has to be adjusted to where the child is in their development.
  • Vygotsky: Teaching should aim to challenge the child by giving tasks just above their actual competence into the Zone of Proximal Development.
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