The development and growth of identical twins is a good example proving that environmental influence on the psychological development of twins is very important, and should not to be neglected by parents.
Once in 80 cases, twins are born. Less often at the same time, triplets or more are conceived. Triplets are born once in 6.400 pregnancies, quadruplets once to 512.000, peters at 41 million pregnancies. Twins can be conceived in different ways. Sometimes it happens two eggs to ripen at the same time, and both of them to be in the same ovary, or one at a time in each ovary. If at that time there is a possibility of fertilization, it is very likely that both egg cells will be fertilized. Thus, twins are conceived. These are two different entities that can be of the same or different sex and develop independently of one another. It is also possible to divide one egg after a few days, usually in the germinal phase, into two, of which two distinctive entities develop, and which evolve separately.
These are so-called single-egged twins because they developed from a single egg cell. They are always of the same sex and outwardly are almost the same because they have identical hereditary traits. They are called identical twins. In fact, it is one being in two parts. During their stay in the uterus, the identical twins usually have joint parents and maternal sex substances and a common afterbirth. A common afterbirth indicates that it is a matter of single-egged twins, in contrast to the separate-egg twins that are both born in their own afterbirth.
The development and growth of identical twins is a good example proving the influence of inherited traits on the psychological development of man, but even more it proves the enormous significance of the environment and the acquired qualities in the formation of the character. Since identical twins have the same hereditary genetic mass, it is understandable that they’re very alike, almost identical in their physical as well as in their psychic peculiarities, such as intelligence, temper, preferences, etc. The similarity of characters of the identical twins, are usually more stressed than those of the bin-ovular twins. Their mutual similarity is even greater if the twins spend the whole stage of development in the same environment, and have the same treatment in it.
This means that the inherited traits of their parents influence the construction of their personality, but are not crucial. If we separate the identical twins and each of them develops in a different environment, they will retain certain psychic similarities, but they will be bigger than in non-twin sisters or brothers. However, their mutual similarity will be much lower than when identical twins live and are exposed to influences and factors of the same environment. The same thing will happen if identical twins stay in the same environment, but the environment treats them differently. In such a case, they can be formed as different individuals, regardless of the fact that they inherit the same hereditary traits. If there is no obvious physical difference, it would be hard for anyone to assume that it’s one person in two editions.
The observation of the psychological development and the formation of a person in the identical twins convincingly suggests that the environment has a much greater influence in their formation as a character than the inherited characteristics of the parents themselves. This knowledge gives the right and the duty of the parent to treat the twins with greater responsibly in their social development than to rely solely on the genetic predispositions. Therefore, there should be a conscious and planned influence in the development in the case when the twins were born, in the positive sense of the word.
In the family, two girls were born as identical twins. Until they turned four, they developed in an identical way. Not only is it difficult to distinguish them, but their behavior is also almost identical. In the fifth year, one of them – Anne, is suffering from poliomyelitis – child paralysis. Until that moment, parents treated the sisters equally. But because of Anne’s illness, understandably, they change the attitude. For a while they are worried about her life, and later the fear arises that Anna will remain motionless forever, because the disease paralyzed both her legs. It is understandable that Anne is treated with great care and tenderness, striving to show all their love to her.
But the disease itself, misled the parents to raise her wrongfully. They begin to spoil her, to fulfill all her wishes, to grant her everything, to do for her what she herself could have done. Under the influence of such exaggerated concern, Anna begins to change. She becomes spoiled, capricious with unreasonable demands and constantly engages her closest surroundings to satisfy her demands, which are often irrational. From day to day, she increasingly strengthens her self-esteem, selfishness and insubordination.
At the same time her sister Emma begins to change. Because of the fear for Anna’s future, the parents simply forgot their other daughter. They pay less attention to her than before, considering her to be independent and grown enough, so they leave her alone to play, entertain and develop herself. Such a change in a parent’s attitude is not due to a lack of love, love has never been omitted. The reason is ignorance- ignorance about the psychic needs of the child and their preoccupation with the illness of the other daughter.
But Emma is too small to be able to understand and accept the change in her parents’ behavior towards her in favor of her sister. To the unintentional neglect she began to react with envy and jealousy. She feels that she has been deprived of parental love and she has a feeling of endangered status in the family. She considers herself unnecessary and unimportant in the home. With the emergence of such emotions in her social life, Emma begins to change her behavior. She holds back to herself, becomes lazy, irritable and impulsive, spiteful towards her parents, constantly arguing with her friends. She is increasingly picking on her sick sister, and with minor mischiefs she is reacting to her sister, as a result of her “privileged” position in the family.
Emma’s deviant behavior is a consequence of a sense of insecurity, deprivation, dissatisfaction and jealousy, due to the unreasonable changes in the behavior of the parents. The same changes occur in Anna’s behavior, and her expectations that she should have a privileged status in the family and that it is the environment’s duty to put her in the spotlight, because the parents themselves unconsciously suggested such expectations.
The example with these twins suggests that they began to differ in their behavior and developed into completely different individuals at the moment when the environment began to deal with them differently. The conclusion is that the environmental influence is much stronger than the inherited properties that are similar for the identical twins.