Introduction
Human behavior varies from individual to individual. The tendencies to commit crimes, be more aggressive or to be more intelligent are all indicators of human behavior. Biologically, speaking, this behavioral outcomes are a direct result of hormones and genes. The relation between these two aspects shall be examined below.
A contrast of the role of heredity and hormones
While hormones have clearly defined roles throughout one’s lifetime, genes, which affect heredity, are responsive to the environment and their role clearly changes with respect to the environment. It should be noted that heredity is not some sort of master puppet holding the strings and controlling the environment. As a matter of fact, genes change or evolve based on the environment hence explaining the reason why things such as mutations and variations occur. Therefore, the way heredity influences human behavior at one point in time may not necessarily be the same way it does years to come. Conversely, hormones are very specific in nature, their presence or absence may change but their role remains invariably the same. For instance, the hormone insulin is always responsible for regulation of glucose in the body and this role cannot change irrespective of the environment (Dean and Copeland, 1999)
In relation to this argument, the environment affects the concentration or secretion of hormones. However, the availability of genes and hence heredity occurs irrespective of this. It should be noted that the environment in this case refers to all the internal and external surroundings of the body. This sensitivity to environmental changes forms the backbone of the ‘principle of the feedback mechanism’. When the body has been subjected to an unusual situation that stimulates fear within the subject, then the brain will be stimulated to produce the hormone adrenaline. This hormone increases glucose concentration in the muscle tissues and prepares the body for flight. When the subject decides to run away from the situation, he has been empowered through the actions of this hormone. On the other hand, when the subject has reached a safe destination, then the brain stops producing this hormone and waits for the next scenario. The process of waiting for deficiency of the hormone in order to stimulate its secretion is called the negative feedback mechanism. Genes are always present in certain concentrations regardless of the environment.(Van Holde and Mathews, 1990)
In relation to the above argument, one can change the way hormones affect their overall behavior because their concentration varies from time to time. This is not possible in heredity because genes are unchanged. For instance, one can take contraceptives in order to suppress the actions of reproductive hormones such as progesterone. This subsequently affects the overall behavior of the individual because they are either pregnant or not. Similarly, it has been shown that exercise, a balanced diet and healthy living largely contribute towards secretion of some life prolonging hormones. Such healthy individuals are more likely to depict positive behavioral traits such as less moodiness. Therefore, it is possible to control the effect that hormones have on the human body but this is not possible for genes.
Consequently, hormone concentrations are largely determined by their surroundings yet this does not occur in genetics and heredity. One is either born with the gene for albinism or not and this cannot be altered through drugs, exercise or any external factor. Also, if one is born with the extra chromosome responsible for down syndrome, then they are bound to remain that way all their lives regardless of the positive environment around them.
Comparison of heredity and hormones
When one talks about heredity they are fundamentally talking about genes or genetics because genes are the basic biological instruments responsible for transferring human characteristics from parents to their offspring. Consequently, all the major questions and controversies associated with genetics apply to heredity; one such example is the nature versus nurture controversy. Some individuals argue that nature is itself the most important determinant of an individuals’ characteristics. These researchers argue that our ability to learn, control our temper or be guided is largely determined by a genetic program that has nothing to with our surrounding. Therefore, heredity is the background behind the ‘natural’ part of this argument. On the other hand, others assert that our surroundings or the interactions we partake affects our behavior. This argument forms the backbone of the social learning theory. After an analysis of this argument, one can see that heredity is part of the bigger picture. It forms the framework for the nature versus nurture argument. However, the nature of the human being with regard to behavior is not just a part of heredity alone. Hormones provide the mechanism for actualizing some of these functions. Consequently, both hormones and heredity affect human behavior but heredity is the foundation and hormones form the structural components. (Faraone et al, 1999)
Heredity and hormones are also quite similar with regard to their influence on human behavior. Genes can affect other genes which affect one’s behavior. Similarly, hormones can be stimulated by other hormones and this have an overall effect on behavior. For instance, there are certain genes that are recessive (hidden) in the female body while they are dominant in the male body. This is because the presence of the Y chromosome in males activates these genes. These are what are called the sex-linked genes. For instance, the gene responsible for growing hairs in ears is only prevalent in males and inactive in females. Similarly, tropic hormones affect the production of endocrine hormones which affect behavior
Conclusion
The influences of hormones and heredity in human behavior are similar in that both form the backbone of the nature vs. nurture controversy and both are affected by each other. However, the two are different because heredity represents the unchanged while hormones fluctuate from time to time depending on the external environment.
Reference:
Van Holde, E. and Mathews, C. (1990): Integration and control of metabolic processes; Cummings publishing group – p.790-792
Dean H. and Copeland, P. (1999): Living With Our Genes, Prentice Hall, pp 368
Faraone, M. et al (1999): Genetics of Mental Disorders: A Guide for Students, Clinicians, and Researchers; pp 272, Guilford Press
