Effects of Heredity and Environment on our Personality!
Every individual on this earth is different from the other. No one person is fully like other person.
Every person differs from the other, either physically or psychologically. Even the twins are no exception to this. They differ in some aspects or other. Particularly when we look at people from psychological point of view these differences are quite obvious. In many instances even the children differ from their parents.
They will have some similarities with some forefathers or grandparents instead of their parents. What makes these differences to exist? What are the causes? The answer to these queries can be traced from two factors, viz., heredity and environment.
The basic sources of personality development are heredity and environment.
Heredity refers to the genetic inheritance received by every individual at the time of conception. The origin of every human life can be traced to a single cell called zygote. It is formed by the union of sperm and ovum.
The sperm and ovum will contain 23 pairs of chromosomes out of which one will be sex determining chromosome. Female will have 23 pairs of XX chromosomes. Male will have 22 pairs of XX and 2 single, represented as XY. X chromosome from mother and Y chromosome from father will lead to male offspring, XX from both parents give rise to female. In each chromosome there are innumerable genes.
These genes are the real determiners of hereditary characteristics—which pass on from one generation to the other. At the time of conception, the genes from chromosomes of both the father and the mother fuse together and determine the traits of the offspring to be born.
The physical characteristics such as height, weight, colour of eye and skin, social and intellectual behaviour are determined by heredity. Differences in these characteristics are due to the change in the genes transmitted. Fraternal twins also differ from each other, because they are born out of different genes. However, we find more resemblances in identical twins because they are born out of monozygotic.
In simple terms environment means the society, the fields of society and even the whole world. But here, the word environment is restricted to mean the environment within mother’s womb and just born, as well as the environment around the individual.
Like heredity, environment also has been found to play a very important role in determining the behaviour and personality development of an individual. The environmental influences are those which act upon the organism at the earlier stages of development, i.e., before and also after birth.
Environment includes all the extrinsic forces, influences and conditions which affect the life, nature, behaviour, the growth, development and maturation of living organism (Douglass and Holland).
Hence, we can say that environment means all that is found around the individual. The zygote is surrounded by a jelly like substance known as ‘cytoplasm’. The cytoplasm is an intracellular environment which influences the development. Though the life begins with single cell, in the process of cell division several new cells are formed and a new internal environment comes into existence.
As the fetus develops the endocrine glands are formed. The hormonal secretion by these glands gives rise to another intracellular environment. Hormones are necessary for normal development, but defects in hormone secretion like over or under secretion may lead to congenital deformities.
The growing embryo is surrounded by amniotic fluid in the uterus which creates another environment. This fluid will provide the necessary warmth and protection against the dangers due to organisms and other chemical effects on fetus.
The fetus is also connected to the mother by the umbilical cord, through which the nourishment is supplied. Sufficient nourishment is necessary from the mother. Otherwise the child will suffer from malnutrition. The defects in mother like drug or alcohol addiction, smoking, malnutrition, diabetes, endocrinal disturbances, small uterus and such other problems cause many problems in child.
The psychological state of mother like over excitement, depression also may cause damaging effect on the child.
After nine months, the child is born and enters a new environment which is entirely different. A new life begins in a new environment. This new environment will have a different culture, ideology, values, etc.
The home atmosphere, parental love and affection, association with sibling, neighbours, peers, teachers, etc. will create an entirely different and new atmosphere. This is called social environment. All the social factors stated above shape the personality of the child.
There is a long standing controversy regarding the importance of heredity and environment. Supporters of heredity say that the environment cannot change a dog into a goat. On the other hand, the environmentalists are of the opinion that for the development of a plant only seed is not important but also environment like sunlight, manure, water, etc.
Innumerable studies have been conducted on both sides. However, the results indicate that heredity and environment are interdependent forces. Whatever the heredity supplies, the favourable environment brings it out. Personality characteristics attained by heredity are shaped by environment.
Nature vs nurture is a popular cultural catch phrase used to describe an ongoing argument that dates back to the 13th century. This debate deals with the roles that heredity and environment play in human development. The basic argument has one side contending the people act as they do because of genetic predisposition or animal instinct. The other side, however, says some so called predispositions are in fact learned behavior or environmentally influenced.
Present day studies into the human genome makes it clear the both sides are somewhat correct. Nature, heredity or genetics, in other words, does endow humans with a variety of inborn traits, abilities and skills. But it is nurture, or the environment that takes the innate tendencies and molds them as we grow to adulthood and on. This does not end the nature vs nurture argument because scientists are currently embroiled in on going disputes about how much is nurture and how much is nature.
It’s well known that genes, one taken from each parent, determines traits like eye color or hair color or which hand is the dominant hand, left or right. These traits are encoded in every human cell in the body. Scientists who espouse the nature theory also say that abstract traits such as intelligence, aggression and sexual orientation fall under their purview, too. These traits, along with intelligence, for instance are naturally encoded in a person’s DNA. Scientists are on the hunt for the specific genes that may cause a person to commit crimes or lead to addiction. Perhaps the biggest modern day hunt is to find the gene that causes homosexuality. It is called the “gay gene.” Most scientists believe this “gay gene” exists because nearly all homosexuals maintain knowing their difference from birth.
Studies have been done, particularly on twins to test the hypothesis. For example, if genetics play no part in sexual orientation then fraternal twins, raised under the same conditions, we be alike, regardless of their genetic makeup. However the studies show the twin similarities manifest even when raised under different environments, tending to validate the nature theory.
However, scientists on the other side claim that only the environment matters when determining human traits and skills. Upbringing is the overriding factor, meaning that if your child is gay, you probably raised him that way. Many of these scientist maintain they can train or teach anyone to be anything they choose for them to be, totally discounting natural variations. More studies on twins, these identical show they are never exactly alike regardless of how they are raised, no matter what.
So, are people born the way they are? Or do they develop the way they are over time, shaped by their environmental experience? Experts on all sides do agree that nature vs nurture is not the same as cause and effect. To put it another way, just because a gene may increase the likelihood of a given behavior, it is never a case of the gene made me do it. So the bottom line remains that just because we may be genetically disposed to be one way, we still have the ability to choose how we are as we grow.
Filed Under: Science & Technology