There are two forces that shape development of a child; their genes and their environment otherwise referred to as nature vs. nurture. Even at the very beginning when the egg combines with the sperm the organism is more then merely the genetic information contained in those parts, the egg contains important nutrients that will interact with the genetic material as it develops (Goldstein).
Almost every cell in the body is made up of long chains of genetic material known as chromosomes. Each chain of material contains DNA that makes up a double helix structure which includes the bases thymine, adenine, cytosine and guanine. How those pairs are combined comprises the genetic code of the individual (Goldstein). A gene is a very short length of DNA, it is made up of only a few hundred bases and it is the very basic unit of heredity. Each gene is coded to do something different; one might be for specific proteins that the body needs to develop while others might be used as instruction manuals for other genes. Genes do not code continuously for proteins they function off and on and some might remain dormant for years(Goldstein).
Genes cannot directly affect behavior because they are individually restricted to specific functions, however, genes can affect behavior indirectly. An example of this would be somebody who had a gene that was very efficient at breaking down alcohol and that person goes on to drink two alcohol beverages for several years. That person would probably never get drunk off of those two drinks, while an individual who was unable to process that much alcohol on a regular basis could feel intoxicated for several hours every night. This person because of their genes be more predisposed to becoming an alcoholic then the other should the environmental factors such as stress and social interactions then the other individual(Goldstein). The role of genes is very complex because they interact with each other as they affect many different biological functions.
There are many misconceptions about the role that genes play in an individual’s behavior. One of those myths is that since genes can predetermine a particular behavior rather then predispose that behavior. Because of this an individual with an alcoholic parent might believe that will also be an alcoholic rather then treat it as something that could be a possibility since they could be more vulnerable (Goldstein). Another myth is that if something is genetic then it must be universal, this is not correct because if a particular characteristic is in the genetic make up it will be expressed differently in different people. Those characteristics will not be expressed in the same way for different individuals most of the time (Goldstein).
While in most cases genetic characteristics will not be expressed in the same manner investigators who study twins especially those who have been raised apart such as in the case of Jim Springer and Jim Lewis many character traits were the same. These two men are identical twins who were adopted into separate families when they were one month old. They had no contact with each other until they were almost forty years old, however, the similarities in their lives were almost uncanny. Both men were both named Jim, married women named Linda and then divorced and remarried women named Betty. Both men smoke and drink about the same, have the same blood pressure, pulse, sleep patterns, and headache problems. While this is only one case of the similarities of twins raised apart. While the role that genes play in development goes beyond hair or eye color environmental factors cannot be discounted.
As more research is done on genetics and heredity in relation with human behavior more concrete answers will be discovered. But the evidence that is currently available points to the fact that while an individuals might be more predisposed toward certain disorders, scores on intelligence tests and other behaviors might have links to genetics, environmental factors must be taken into account because the environment and genetics work together in the process of development (Goldstein).
The effects the environment has on development starts at conception because it involves more then the type of house the child grows up in and how the family interacted with each other. It includes everything outside of DNA including the womb, family school and culture.
The prenatal environment is rich with hormones which effect how the fetus develops. In case the child is male then male hormones will be released that cause the fetus to develop the male sexual organs. Those hormones also affect how the brain develops and some scientists believe that the sexual behavior and orientation is partly dependent upon the presence of specific hormones released during that period (Goldstein). Another important factor in the suitability of the prenatally environment is any drugs both prescription and illegal that the mother is taking while pregnant. As development is so rapid during the prenatal period that the fetus is very vulnerable to changes in its environment (Goldstein).
Food is a basic requirement of development and without it the child will die. Even if infants get enough calories the type of food eaten can have an effect on their development. Insufficient protein in the early stages of life can cause fewer brain cells to divide resulting in some mental impairment. While a lack of protein can cause problems consuming too many empty calories have been linked with increased aggression, fatigue and stomach pains (Goldstein).
The question of how important genetic factors (nature) and environmental (nurture) in shaping the characteristics of a developing individual has been debated for years. Throughout the twentieth century the science of Psychology underwent a drastic change. There was a disagreement between psychologist about the importance of introspection and the existence of mental elements (Schultz). The change in psychology started with the movement toward functionalism and away from structuralism until 1913 when John B. Watson set out the theory of behaviorism. The basic tenets of behaviorism were straight forward calling for a scientific psychology that could objectively in terms of stimulus and response (Schultz). The early Behaviorists closely aligned themselves with the nurture side with the emphasis of their research on the environment and how it shaped development. Scientists who were studying evolution and biological training emphasized the effect of genes on behavior or nature. While some behaviors such as aggression or alcoholism seem to be more influenced by genetic factors understanding how much of behavior is influenced by genetics is harder to determine.
One of the problems with the nature argument is how is it possible to explain the existence of actions for which there was no obvious pressure of natural selection. If our behavior is regulated by genetics then how could individuals sacrifice their lives to save another? That sacrifice removes that genetic material from the gene pool which would be less then productive from an evolutionally point of view (Csongradi).
While the nature-nurture debate continues it has broad implications about the way a society chooses to intervene in social problems (Goldstein). If an individual believes that alcoholism is caused by a genetic predisposition then that individual would be more likely to support programs that would focus on preventing alcoholism in children of known alcoholics. On the other hand if an individual believed that environmental factors were more important in development that individual would be more likely to remove alcoholics from stressful environmental factors to inhibit the need to drink.
The Human Genome Project was an ambitious project started several years ago in order to map the entire genetic code of human beings. While many reports have been published focusing on so called discoveries of genes that had the ability to kill hiding in our genetic code or complex traits. However now that the genome has been fully mapped researcher have come to a new understanding about the nature vs. nurture debate. The amount of genetic material is not sufficient for biological determination to be possible (Davies).
I feel that focusing solely on genetics as the cause of all behavior is a cop-out. By using the argument of being genetically programmed to be a bad person individuals do not have to take responsibility for their own actions. Being abusive to family members, robbing a bank, or failing at a job and being able to blame something else especially something that cannot be changed such as DNA allows the worst human behaviors to be excused. The environment plays a larger role in development then genetics and has the ability to be overcome should the environment have been less then perfect.
Works Cited
Csongradi, Carolyn. “What Is the Relationship Between “Nature” And “Nurture” In the Aquisiton of Knowledge”. 2008.
Davies, Kevin. “Nature Vs Nurture Revisited”. Web.
Goldstein, Patricia M. Wallace; Jeffrey H. An Introduction to Psychology. Ed. Edgar J. Laube. Boston, Massachusetts: McGraw Hill, 1997.
Schultz, Suane P. Schultz; Sydney Ellen. A History of Modern Psychology. 8th ed. Belmont, CA: Thomson Wadsworth, 2004.