Jean Piaget: Biography and Contributions to Psychology

Jean Piaget, a prominent figure in developmental psychology, was known for his theories that helped create an understanding of early development. In the field of psychology, developmental psychology has played a crucial role in understanding the development of the human mind. Combining evolutionary findings with present-day research developmental psychology aims at studying the change in human beings at the various stages of life. Developmental psychology aims at catering to the changing emotional and social needs of individuals.

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The following article looks at a brief introduction of Piaget’s life, followed by understanding his two most prominent theories, Theory of Cognitive Development and Theory of Moral Development. The article also looks at influences of his theory on other works and criticisms of these theories. 

Jean Piaget: Biography and Developmental Theories 

Jean Piaget was a Swiss Psychologist who was born in the French-speaking part of Switzerland. Piaget was passionate about biology and philosophy right from an early age. He, later on, went to combine his two interests and was described as an epistemologist. Epistemology studies philosophical concepts such as knowledge, ethics, morality and logic. Piaget is acclaimed for his work in developmental psychology, where his theory of cognitive development and theory of moral development are two of the most prominent theories in the field. Apart from these two, Piaget is also known for his influence on education, as well as philosophers. Piaget’s work on understanding cognitive development was influenced by his observations amongst younger children, who were consistent in the mistakes they made, unlike others. His work on understanding morality in children was influenced by making observations, amongst children once again, which led to the development of Piaget’s theory on morality which was also influenced by Sigmund Freud’s theory of psychoanalysis. Freud’s theory of psychoanalysis looks at personality development. Freud’s theory looked at the three structures of personality, the Id, Ego and Superego, which influenced Piaget’s theory of moral development. 

Read: 10 Famous Psychologists and Contributions

Piaget: Theory of Cognitive Development  

The theory of cognitive development looked at the development of children from birth until the age of eleven. Piaget’s theory was based on observations of his daughter and nephew. Piaget found his theory on the Schema Theory developed by Frederich Bartlett (1932). Schemas are mental frameworks that help organise new information into pre-existing units created from previous knowledge. Piaget stated that children are born with some schemas which are modified as a result of experience and further information. Piaget termed the modification of schemas as adaptation. Piaget divided adaptation into two types. 

  1. Assimilation – when new information can be categorised into existing schemas 
  2. Accommodation – when new schemas need to be made or modification of existing schemas need to happen to accommodate the further information

Piaget stated that the development of a child is divided into four stages. Each stage was distinguished by an age range and specific developmental milestones associated with it.

Stage 1 – Sensorimotor (birth to 2 years) 

Infants in this stage lack dominant schemas except for schemas of senses (such as sucking). Due to a lack of formal schemas, children in this stage are limited to their knowledge about their world. As a result, infants cannot distinguish themselves from the environment as they lack knowledge of the environment. This is known as profound egocentrism. Children in the early parts of the stage, (up to 8 months) lack object permanence. This means that if an infant can not see the object, the object ceases to exist. This also means that a child will only look in the place where the child last saw it. Object permanence completely develops at the age of 18 to 24 months, as children begin developing schemas about the world around them. 

Stage 2 – Preoperational ( 2 to 7 years)

Once object permanence is established, children begin to think and use language and visual representations (such as drawings) to express their thoughts, however, cannot distinguish between animate and inanimate objects. Children also develop egocentrism, where they can not comprehend another person’s perspective when looking at objects. Children begin thinking but still lack concepts such as reversibility ( for example a multiplied by b is equal to b multiplied by a) conservation (for example 2 glasses of the same size with water are poured into two glasses wherein one is taller than the other, the child will believe the taller glass has more water) and classification (for example a Labrador is a dog as well as a mammal). 

Stage 3 – Concrete Operational (7 to 11 years)

The development of concrete schemas characterises this stage, hence the name. This stage, children develop logical thinking and understand conservation. They develop reasoning and logic. However, they still can not grasp abstract concepts and are bound by reality in their thinking. Egocentrism begins to diminish, and children start to learn to look at other people’s perspectives and can comprehend the notion of differing thoughts and perceptions of other people. 

Stage 4 – Formal Operational (11 years onwards)

Children are considered to have fully developed mental structures at this stage. Children at this age can understand abstract concepts such as morals and love. They are also able to imagine themselves in other people’s positions and roles without actual enactment of the incident. They even can comprehend abstract and hypothetical situations which they have never been exposed to. Self-consciousness and self-focusing emerge in this phase. A distorted version of egocentrism returns where the individual is faced with the inability to distinguish self from others which creates a distorted sense of self and others.

Influences and Critiques of Theory of Cognitive Development  

Piaget’s theory of cognitive development allows other psychologists to understand development in other forms such as Lev Vygotsky’s theory of language development. Piaget’s theory is generalizable across several cultures which have been proven. However, there have been criticisms as Piaget ignored the importance of language. He also ignores the impact of the environment and upbringing’s influence. (nature and nurture) His theory, although generalisable does not hold in cases of feral children as they don’t have exposure to nurture, which poses as a critique of his theory.

Piaget: Theory of Moral Development

The theory of moral development is seen to have a significant impact on the understanding of morality in children. The theory looks at morality, the ability to distinguish right from wrong, and it’s development. Morality is dictated by the need to live in a society, the survival of the human race hence creating norms for right and wrong. Sigmund Freud was once again a significant influence in laying the foundation for morality. He stated that morality develops by the age of 6. Children below the age were seen as belonging to the pre-moral stage where the difficulty to comprehend rules as stated in his previous theory (in the preoperational stage) as children in this age group also cannot see from the perspective of others. Piaget worked on understanding morality in children through a game. He theorised two forms of morality. 

  1. Heteronomous Morality (5 to 10 years)

In this stage, children do not have autonomy as they are considered too young, and hence morality is imposed by others (such as parents and teachers). Children at this stage believe that the morality imposed (in the form of rules0 must be followed as breaking will result in punishment. Here, children do not question the rules and believe that the rules are unchangeable and know that they result in consequences. Hence the amount of damage influences the extent to which the action is wrong even if it was accidental as it is considered “bad behaviour”.

2. Autonomous morality (10 years onwards)

This stage is also known as moral relativism as here, the children and people above the age of 10 see themselves as being old enough to make their own rules. The egocentrism which is slowly diminishing as the children are almost reaching the stage of formal operational where they can comprehend morals and values independently. Here, children understand that the rules are imposed by authority. They understand that the rules in this stage are seen as flexible but some are also fixed. Children over the age of ten also take on moral responsibility where they understand the consequences and despite that, choose to own up to their mistakes. They follow social norms and understand the purpose of punishment. 

Critiques of Theory of Moral Development

Although the study helps understand morality in children as a whole his theory has proven to be very age restrictive which has been disproved as further research by later psychologists noticed morality in young children in the form of telling the difference between the lie and the truth. In his theory, unlike cognitive development, morality is highly influenced by reinforcement from cultural values which was not taken into account. The variations in cultures lead to questioning the generalisability of the theory. However, the theory laid a formation for understanding morality, and it’s development. 


Piaget’s works have been used as a basis for further research by several other psychologists such as Vygotsky. Piaget’s theories are still considered to be of profound importance despite counter-evidence as the two theories covered in the article, the theory of cognitive development and the theory of moral development, help create an understanding for behaviours observed in the various stages of development in a person’s life. Piaget’s findings in the cognitive development theory had been proven to be adaptable cross-culturally, making it a crucial need in understanding developmental psychology. Piaget’s second theory follows the development of morality in children in two phases. One thing to be noted is that Piaget’s theories are not always applicable as the role of the environment; genetics can influence a variation in his fixed age groups. His theories have also been criticised for ignoring the differences amongst children in processing information which makes his theories reliability amongst the general population low as his samples were small and the method of testing for creation of the theories were not standardised. 


Bapat, D. (2019).Moral Development. Lecture, FLAME University.

Bapat, D. (2019).Piaget Lecture, FLAME University.

Cherry, K. (2020). What Are Piaget’s Four Stages of Development?. Retrieved 17 July 2020, from

Holt, R. (1980). Freud’s Impact on Modern Morality. The Hastings Center Report, 10(2), 38. doi: 10.2307/3561279

Jay, M. (2020). Sigmund Freud | Biography, Theories, Works, & Facts. Retrieved 17 July 2020, from

Law, A., Halkiopoulos, C., & Bryan-Zaykov, C. (2010). Psychology. Oxford, U.K.: Pearson Education.

Mcleod, S. (2015). Piaget’s Theory of Moral Development | Simply Psychology. Retrieved 17 July 2020, from

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Shubha Arvind is currently pursuing a degree in Psychology with an Open Minor at FLAME University. Her passion for culture studies, sociology and film and she aims to focus her minor around them. She actively participates in discussions and hopes to make a change. Her hobbies include playing the violin, swimming and art.