Basically, human development is a very complicated process, which is not fully researched till the present moment.
To put it more precisely, there exists a variety of theories on human development, but, still it is hardly possible to find a theory that all specialists could recognized as a universal and absolutely correct. In stark contrast, on researching the problem of human development, specialists develop their own theories, though often they rely on works of their predecessors. In this respect, it should be said that works of such psychologists as Jean Piaget and Lev Vygotsky, produced a profound impact on further researches and theories concerning human development, including works of Lawrence Kohlberg, who basically developed Piaget’s ideas and created his own theory. At the same time, what is really important to underline and what really unites theories developed by Piaget, Vygotsky and Kohlberg is the idea that human development occurs in accordance with certain stages in their physiological and psychological development. In such a way, each stage can affect the development of thought, language, cognitive development, social role of an individual, etc.
First of all, it should be said that Jean Piaget may be viewed as one of the major contributor to the contemporary views on human development. In fact, his theory of cognitive development became the basis for the scientific works of Lev Vygotsky as well as of Lawrence Kohlberg. At the same time, it should be pointed out that Lev Vygotsky attempted to create quite original and unique theory which distinguished his ideas from those of Piaget. To put it more precisely, in his theoretical developments he heavily relies on socio-cultural context in which the development of an individual occurs.
In such a way, it should be pointed out that both Piaget and Vygotsky worked on the similar problems and what is more Vygotsky works are to a significant extent based on Piaget’s works, or to put it more precisely, on reevaluation of Piaget ideas and the criticism of his methods. This is why it is primarily necessary to underline that Vygotsky believed that “Piaget had developed a clinical method that revolutionized the study of children’s language and thought”¯ (1962:155).
In fact, Vygotsky could hardly disagree with achievements of Piaget and his contribution to the study of children’s thought and language. Not surprisingly that Vygotsky in his work “Thinking and Speaking”¯ underlines that Piaget’s forte is “the unearthing of new facts, their painstaking analysis, their classification ”“ the ability”¦ to listen to their message”¯ (1962:175). Piaget’s studies gave detailed picture of children’s thinking. He asserted that development occurs in distinct, measurable, and observable stages. In this respect, speaking about the language and thought, it is worthy to note that Vygotsky agrees with Piaget and remarks that there is pre-intellectual stage in the development of language and pre-language stage in the development of thinking.
Furthermore, it should be pointed out that Piaget, unlike many his colleagues of his epoch, focused on what children have, and not what they lack. And one of his most significant findings is the idea that the difference between adults’ and children’s thinking is qualitative not quantitative and again Vygotsky did not really argue with Piaget and even supported his ideas.
Nevertheless, there were some serious debates and criticism of Piaget from the part of Vygotsky. In this respect, it is worthy to remind that one of the central concepts of Piaget was the effects of egocentrism on thought and language and on development of children at large. To put it more precisely, he states that “from the genetic point of view, one must start from the child’s activity in order to understand his thought; and his activity is unquestionably egocentric and egoistic. The social instinct in well-defined form develops late”¯ (1992:276). According to Vygotsky interpretation of Piaget’s views on egocentrism and children’s development, egocentric speech reflects that the child is in the preoperational developmental stage. Then gradually as the child develops his egocentric and than social speech and then the logic appears late in the developmental cycle.
Furthermore, Piaget believed that egocentric thought is the genetic connection between the inner speech and the logic stage. Piaget stated that egocentrism decreases at school age because it does not fulfill a function and egocentric speech has no future. As a result, it diminishes with the disappearance of egocentrism.
At first glance, Piaget’s views seem to be quite logical and convincing but Vygotsky did not fully agree with Piaget and criticized some of his theoretical and methodological assumptions. In fact, Vygotsky believed that Piaget combined psychology and philosophy even though he attempted to avoid theorizing. Not surprisingly that in his book “Language and Thought in the Child”¯ Piaget emphasizes that his work is “first and foremost a collection of facts and documents. The bonds uniting the various chapters are those that a single method can give to diverse findings ”“ by no means of those systematic exposition”¯ (1995:1).
Also, Vygotsky overlooked the role of the child’s activity with relation to the thought process and he arrived to the conclusion that observing merely the individual was not thorough enough to understand children’s development. In fact, Piaget’s theory assumes that development is unidirectional with all children reaching each stage at approximately the same age. At the same time, by examining the world and society much more data are gathered.
Not surprisingly, according to Vygotsky, Piaget did not succeed in keeping his works within the bounds of factual science.
In actuality, Vygotsky estimated that many of Piaget’s theories lacked the necessary scientific facts. Moreover, there was even more significant flaw in Piaget’s works, since according to Vygotsky, Piaget’s analysis of facts was influenced by his theory. As a result, this caused Piaget to related egocentrism to all other traits, without objectively analyzing facts that naturally undermined scientific reliability of his works. To put it more precisely, Vygotsky disagreed with Piaget’s inference that egocentric thought is impervious to experience. He also disagreed with Piaget assumption that the development of children could not be impeded or accelerated through instructions, which Vygotsky, in his turn, found very helpful.
Furthermore, Vygotsky was also very skeptical about Piaget’s theoretical assumption that developmental growth was independent of experience and based on a universal characteristic. In stark contrast, Vygotsky estimated that development is complex and is affected by social and cultural contexts. Also he stated that biological and cultural development were interrelated and did not develop in isolation. This is why socio-cultural environment was very important for the development of language and thought and, due to their close interrelation, bilingual education could contribute dramatically to significant personal, intellectual and socio-cultural progress of children. This is particularly important since Vygotsky believed that intellectual development was continually evolving without an end point.
Another conflict between Vygotsky and Piaget was the latter’s explanation of development as the notion that concepts should not be taught until children are in the appropriate developmental stage. This conflicts with Vygotsky’s zone of proximal development and developmental theories. Also Vygotsky noted that instruction that is oriented toward development is ineffective concerning the child’s overall development.
Thus, it should be said that Jean Piaget basically distinguished four stages in the development of humans. The first stage is sensorimotor period, during which the initials schemas are formed through the differentiation of the congenital reflexes. At this stage, the development of special abilities and understanding of the world occurs. The second stage is the preoperational stag, during which an individual learns to use and represent objects by images and words, i.e. learn to use symbolic thinking. This stage is characterized by sparse and logically inadequate operations.
The third stage is the concrete operational stage, during which an individual learns to use logic appropriately and basically a person gets rid of egocentrism, develops logical thinking and is able to concrete operations, while abstract thinking remains underdeveloped at this stage. Finally, the fourth stage is the formal operational stage, during which an individual learns to think abstractly, reason logically, and draw conclusions from the information available. At this stage, an individual is able to understand abstract concepts, such as love, friendship, etc. (Piaget, 1992)
In this respect, the stages of moral development of Lawrence Kohlberg basically rely on Piaget’s ideas of cognitive development, but Kohlberg lays emphasis on the moral development of an individual. Basically, he distinguishes three stages of human development. The first stage is the pre-conventional stage. This stage is characterized by the obedience and punishment orientation and self-interest orientation. In other words, an individual tends to be obedient, often because of the fear of punishment and his/her personal interest dominates, making his behavior and perception of the world highly egocentric. The second stage is conventional stage. This stage is characterized by interpersonal accord and conformity that means that individuals tend to live in accordance with the existing social and moral norms imposed on them by adults and social environment. Therefore, the orientation on the authority and social order maintenance dominate in the behavior of an individual at this stage. Finally, there is the post-conventional stage when the formation of an individual and his/her personality is accomplished. To put it more precisely, an individual perceives him/herself as an independent personality oriented on the social contract, who tends to live in accordance with universal ethical principles (Kohlberg et al., 1983).
Thus, taking into account all above mentioned, it is possible to conclude that the progress of human development theories was, to a significant extent affected by works of Jean Piaget, who became one of the pioneers in the exploration of the domain of human development. His cognitive theory became the foundation for cultural-historical psychology of Lev Vygotsky and the moral development theory of Lawrence Kohlberg. At the same time, it should be said that each researcher brought in some new ideas, which differentiated his theory from all others that allowed to better understand the process of human development.