Theories of child development can be classified into three broad categories. The first is psycho analytic theory propounded by Sigmund Freud and his associates. This theory gives much importance to unconscious motivation developed especially in the early period’s of life and it determines the personality of the individual in the later parts of life also. The second is behaviouristic theory of child development which lays stress on the tion between stimulus and response. The major advantage of this category of theories is that it can be experimented and verified in clinical setting and thus these theories are more scientific in nature. The last category is cognitive theory of child development. It is a molar approach of explanation of human development and it takes the total situation facing the mind into account. It lays stress on perception and its organization responsible for learning and development.

Some of these theories are being described below:

1. Psychoanalytic Theory (Freud) : According to this theory, every child passes through five stages of psycho-sexual development. These stages are given below.

(a) Oral stage: At this stage focus of pleasure is mouth. When child sucks milk from the breast of her mother, he not only quenches his hunger but also gets pleasure by the excitement of mouth.

(b) Anal stage : When child attains the age of two the focus of pleasure shifts from mouth to anus. The child obtains pleasure from the activities related to anus during this period. That is why defecating is enjoying for the child.

(c) Phallic stage : This period starts at the age of three and lasts at the age of six. Here the focus of pleasure shifts from anus to sexual organs like pennis or vagina. “That is why habit of masturbation is common in children. Two special complexes also develop during this period (1) Oedipus complex-here the male child wants his mother more but finds his father as a powerful rival. He wants to destroy this rival but he is unable to do so. (2) Elektra complex-Here female child comes closer to her father and hates her mother. 

(d) Latency stage : During this period all earlier forms of sexual activities are stopped. The child takes interest in learning skills and in the development of social and religious values. This stage helps the child to develop his super ego on the basis of his ego.

(e) Genital stage : The focus of pleasure shifts to the member of the opposite sex by using genital organs here. This stage starts after 13 years. 

2. Ericksons’ Theory of Psychosocial Stages : Erickson has proposed another theory of stages of child development. He divides stages of development into eight phases marked by specific developmental characteristics. 

(i) The infant develops a sense of trust in himself as well as in the environment. This trust is developed when he finds others at the beek and call of his physiological needs. Contrary to this, if his needs are not fulfilled by the people around him. he aches and cries. As a result, he loses his faith in the people around him.

(ii) When the child attains the age of 1.5 years, he develops the sense of autonomy in him. He does not want help from others. If parents give them reasonable freedom, it will develop confidence in them. Children who are not given such freedom to explore the environment, develop suspicion and doubt about their abilities. When they perform a task they become shy and hesitant. They are afraid of their mistakes which can bring about shame for them.

(iii) At the age of three, rapid growth of children in all dirnensions is seen. At this age, the child starts to take initiatives on various tasks. The social horizon of the child begins to spread from home to neighbourhood and then to school. At this age, children also begin to develop the sense of right or wrong. Feeling of guilt is developed when they do not follow moral principles and codes given by their parents and teachers.

(iv) Fourth stage of development in the life of ld starts at age of six and comes to an end just before adolescence. During this period child utilizes his energies for self improvement and for the conquest of the outer world. He shows his industry and hard labour in all directions with special emphasis to motor field. The child wants to understand different mechanisms of the world through his toys and other usable articles. If the above opportunities are not given to him and the child is still treated as a child of low mind, it develops inferiority complex in him.

(v) When the child attains the age of thirteen he begins to fight for his identity in his group. He wants to become a leader in various activities and through this he wants to gain popularity among girls. Contrary to this if he is completely disregarded in the group to which he belongs. his identity is diffused.

(vi) Adulthood period starts at the age of 17. In the early years of adulthood, the individual wants to increase his social circle as large as possible. If he is amiable by nature, he is liked by others and if he is selfish, self centred or intolerant or he is hated by others especially by the girls, he starts to live in isolation. Many tragic songs and dramas are written during this period.

(vii) In the middle years of adulthood, generativity is seen. The individual exposes himself through any outstanding efforts in any field. He wants to live for others. That is why he is very much interested to see a better and disciplined world around him. The condition of self absorption is seen when an individual does not receive any encouragement for his tasks from anywhere.

(viii) Last stage is known for the integrity of the person to his profession, group, organization and institution to which he belongs. When justice is not maintained or an individual is not paid and recognized according to his efforts, his integrity is turned into despair.

3. Robert Sears’ Development Theory: This theory represents the behavioural approach to the study of child development. According to Robert Sears learning experiences of the child are the result of stimulus-response associations that may result either classical or operant conditioning Procedures. Thus according to this theory, development is a process of observable social interaction. The more there is social interaction, the more there is learning which is enhanced by reinforcement also.

There are three broad phases of human development according to this theory which are given below 

(a) Phase (1) Rudimentary behaviour : Initial behavioural training starts during this period. The period of this stage is birth to sixteen months of age. During this period the infant is activated by his innate needs of hunge thirst, motor movement, defecation etc. These needs create tension in him and in order to reduce this tension, the infant is motivated for action. When action of the infantis reinforced by positive response, his needs are satisfied. The infant is very much selfish in his behaviour in the beginning and does not care for any social world. But when social world (parents and relativus) fulfills his needs and infant is reinforced for his action of say crying learning takes place which makes the learner more learned and goal directed.

Since, the infant here depends on someone else for the gratification of needs, the development becomes a process of social interaction. It is a type of operant behaviour here. The social environment in which the child is born greatly influences the development of the child. If child is not reinforced by anybody. i.e. his needs are not fulfilled, no development will be there. Socio-economic condition of the family. birth order of the child. his sex, the education or profession of his parents etc., affect the development of the child.

In other words, we can say that the first phase of the child’s development interlinks the biological endowments (innate abilities) of the child with his social environment. The more the social environment is conducive to the fulfillment of biological needs of the child, the more learning and development will be there.

(b) Phase II (Secondary behaviour) : When child is reinforced by his parents and other members of the family, and the child’s biological needs are gratified, he comes to develop secondary behaviorr system, i.e., he has to respond to others. If his response is fine he will be motivated. If response of the child is not upto the mark, it will be corrected by others and thus the process of development of correct secondary behaviour goes on.

The secondary behaviour of children starts by imitation. If model to be imitated is good, behaviour of the child will also be fine. The secondary behaviour of children should also be reinforced by parents and others and use of punishment as a technique should be avoided as much as possible because it can create behaviour problems in the child.

During this phase when the child begins to fulfil his needs himself by learning some new behaviour, his dependency on others decreases with age till the child is grown up fully and becomes an independent member of the society.

(c) Phase II (Behaviour motivated): After the age of 11-12 the social boundary of the child expands a lot. The child comes in contact with other parents and their sons and with many people in his school and thus his process of socialization is accelerated. His dependency on others is reduced further but some new dependency in the school increases also. If child is given approval by his parents and other persons of the society that his behaviour is fine, he motivated to repeat that behaviour again and thus the process of development expands. As the number of environmental reinforcers increases, the child comes to identify those persons well who satisfy his needs and he accepts those people as his model.

4. Bandura’s Theory of Development : He gives equal importance to reward and punishment in the development of behaviour. Thus Bandura is mainly concerned with the social development of the individual. He believed that responses which are reinforced are more likely to recur than those responses of children which are not reinforced. Behaviour is learned either through conditioning or observational learning In early childhood many behaviours of children are not approved by parents. Children are rather punished for the execution of such behaviour. Due to this fear, children are conditioned not to repeat that behaviour even in the later periods of life. Thus reward and punishment both are necessary for the moral and social development of the child.

Observation (imitation) is the second mechanism responsible for learning (or acquisition of behaviour. The child creates some models in his mind or he is impressed by the behaviour of some people and accepts them as his model. These models are imitated by the child. Imitation follows certain principles such as competency, social status, power and similarity of the model with the imitator.

5. Jean Piaget’s Theory of Development : He has explained his theory in the context of cognitive (mental) development of the child. Before coming to various stages of development according to this theory it is better to know various related concepts to understand the theory in detail. These concept are given below:

1. The schema : The concept of schema is applied to the sensory motor behaviour of the infant. The infant does various activities such as sucking milk from the mother’s breast, looking at the objects of the environment and pointing at it and in the process he tries to comprehend and conceptualize the objects, animals or space. This process of conceptualization depends on the sequence of behaviour employed by the infant to adapt to his environment. This is called schema which is not the same in all the individuals. Basic structure, is however the same. Although a particular scheme derives its name from the sequence of behaviour which the schema denotes yet some internal organizational disposition is there to enable the sequence to adapt itself to a number of conditions. As the development of the individual takes place, each schema is enlarged, modified and co-ordinated with other schemas. In this way, more complex schemas are formed.

The sensory motor scheme develops out of reflex behaviour of the infant. When this behaviour is repeated by the infant many times and is responded by others, it is internalized and is gradually converted into cognitive schema. For example, in northern India when a child says mum and is given water by the parents the child conceptualizes mum as water. Many such defects are corrected in the later stage of life. Piaget believes that schemed a (cognitive structure) exists in primitive form even at conception and develops progressively with age.

2. Assimilation and accommodation : The schemas which are acquired in infancy period are practiced and modified in the later stages of life. This process of practice and change is called assimilation and accommodation by the cognitive field theorists. These assimilation and accumulation processes go hand in hand. For example, during infancy when infant acquires grasping schema he pick up objects and grasps them. This grasping of objects is called assimilation, But if that particular object is too big or too small to  grasp it., the child changes his schema in order to manage the new situation. It is called accommodation. The cognitive structure (schema) changes from one stage to another by the process of equilibration. Through this process the child tries to adapt to his changing environment every time to maintain equilibrium between him and the environment.