Human development is affected by several factors. Different studies were conducted to understand the factors influencing human development and two factors were found to play a major role. They are heredity and environment. Heredity explains our growth pattern and determines our how we grow older. We are similar to our parents, not only in terms of physical characters, but also in what we do. In the same way, environment also influences our learning, behaviour and personality. The similarities that we have with our parents depend upon the genetic makeup transmitted from the parents to the child. Heredity may influence many traits such as the colour of the eyes, height and susceptibility to specific diseases.
Similarly, development is also influenced by the environment. Environment, here, refers to the surrounding context, interaction with people, socio-cultural context, political and historical context of the person’s life and many other dimensions. The school has significant role to play in a child’s learning and development. Content, pedagogy, school environment, teachers and peer group contribute to the school environment of a child.
The debate of the importance of role of heredity Vs that of environment is very prominent. Though studies have proved that we all are part and parcel of a combination of both, it sometimes becomes difficult to say which influences more, heredity or environment.
Heredity is a science where we study the role and importance of heredity in different aspects of development. The study of genes, how they are transmitted from one generation to another and how they influence a person, is the subject matter of human genetics. Conception occurs when a man’s sperm cell contacts an ovum. At the time of conception, the 23 chromosomes of sperms combine with the 23 chromosomes of ovum. Genes that are present in these chromosomes carry hereditary traits. Here, it is also important to know that mutation is a process when genetic structures are changed.
Environment refers everything except heredity, which stimulates and influences a person. It includes the person’s family life, social life, economic life, peer group, education and so on. Studies have proved that the role of heredity and environment in development is significant.
This debate is also known as nature Vs nurture, where nature stands for heredity and nurture stands for environment. Nature and nurture have their own role in child development. Two children in the same family getting the same treatment will still have different rates of development. Not only this, their intelligence levels will also be different from one another. This shows that heredity has a great influence.
But, on the other hand, when twins are nurtured in different environments, they are seen to develop differently. Thus, environment also plays a significant role in child development.
The above discussion explains that development happens because of the interaction of environment and heredity where both have a significant role to play. While certain things are determined by heredity, others are developed by the environment.
Principle Of Heredity
The union of 23 chromosomes of the male with that of the female is the cause for conception. Of these, 22 pairs of chromosomes are the same in men and women. These are known as autosomes. The 23rd chromosome decides the sex of the child and is known as sex chromosome. In females this sex chromosome is similar, but in men it is dissimilar.
It is important to understand that there are two types of sex chromosomes, i.e., X and Y, of which X is a long and Y is a small chromosome. The female has only X chromosome while the male has both. When the X chromosome of the female combines with the X chromosome of the male, a female baby is conceived. When the X chromosome of the female combines with the Y chromosome of the male, it results in a male baby.
Chromosomes are made of genetic matter. Each gene determines a different characteristic and we inherit them from our forefathers.
Some people have more X and Y chromosomes than normal. As we know, the normal combination is XY and XX. But sometimes abnormalities set in to create chromosomal combinations such as XXY or XYY or XO. In XXY abnormality, a person will look like a man but will be sterile (Klinefelter’s syndrome). In XO abnormality, person will look like a female but will be sterile (Turner’s Syndrome). In XYY abnormality, the person develops tendencies of delinquency.
Johann Gregor Mendal (1866) contributed significantly in developing the laws of heredity.
He propounded two laws of heredity, namely, ‘Law of Segregation and Dominance’ and ‘Law of Independent Assortment.’ Though he conducted all his experiments on plants, his laws are universally accepted. We can understand his laws in brief as below.
Law Of Segregation And Dominance
If the traits of one gene are not manifest in one generation, it does not mean that they die. They still survive and may come to the fore or become dominant in future generations. For example, if a person has a specific kind of genetic problem, there is a possibility that his son may not express that problem explicitly, but, his grandson may have show it just as he does now.
Law Of Independent Assortment
This law explains that distribution of one genetic trait does not influence the distribution of other traits. For example, in a white family, all will be white but their height may vary.
The above discussions and expiations clearly prove that both heredity and environment have a specific role to play in development and also in education. A balanced development occurs because of the combined role of heredity and environment. A child may have good heredity background, but if the environment in which he or she is brought up is not good, he or she may not develop adequately. On the contrary even if the heredity is not good, favourable environmental factors can help in a child’s development.
Awareness of a child’s heredity and environment is important for a teacher. This awareness will help the teacher understand the reasons behind a child’s behaviour and facilitate his or her development. It also gives a complete perspective of the child’s tendencies, desires, problems and aspirations and helps the teacher to interact with the students accordingly.