Genes Aren't Everything

One of today’s most hotly debated emerging technologies is that of germ-line genetic engineering. This is the process of manipulating an embryo’s genetic makeup in such a way that parents can choose the genotypic characteristics of their children. This includes such alterations as avoiding a familial disease or a genetic disposition to one, selecting an offspring’s gender, or even selecting or enhancing particular personality or physical traits. There are many advantages to this technology, as well as sundry reasons for opposition to it. Particularly, the ability to engineer an embryo’s genes would produce much healthier, fitter future genera. It would also produce offspring who, for the first time in the history of mankind, were not genetic recombinations of their parents. This is cause for alarm to many groups, such as several major world religions and intellectuals sects. The objections raised by organized religions are not ones that I particularly care to argue, as a sect’s doctrine cannot be debated. Yet, the objections raised by many intellectuals are, in several ways, faulty. They argue that genetic engineering would devoid future generations of meaning, rob them of their identities, and create a robotic humanity.

Why exactly does a genetic predisposition force this loss? Why does losing the randomization of our genetic makeup inherently also force the loss of mankind’s identity and our basic meaning in life? How do genes that have been preselected by one’s parents, rather than chosen at random by an invisible molecular force, strip humanity of their identity and purpose, assuming one exists? I feel that germ-line engineering will do little to change the basics of human nature or the concepts of our identity or the meaning of life.

Genes are not the only determinants and predictors of humanity. Our identities, personalities, and physical traits are not wholly determined by our genetic code. Environment acts upon and often manipulates genes. It is the question of “nature vs. nurture” that must be addressed when considering the question of whether or not germ-line engineering would steal our progeny’s identities. Which, our environment or our genes, has greater effect over our eventual development and identities? While I will not attempt to answer this question in this essay, I can safely state that, no matter which one believes to have a greater effect, it cannot be denied that both contribute. R. Grant Steen affirms this: “…the idea that the environment has a complex and subtle impact on the individual is really not at all speculative” (50). This topic, too, has been one of great debate for several centuries, but one that has come closer to a definitive answer through relatively recent psychological study and experimentation on identical twins.

The most reliable way that psychologists currently have to study the effect of genes on human behavior is through twin studies. As Marvin Zuckerman states: “The difference in correlation between identical twins raised together and those raised in different families is a direct measure of the influence of shared environment” (Zuckerman qtd. in Hettema and Deary 94). This is due to the fact that identical twins share exactly 100% of their genetic code. Not only are identical twins physically alike, but they are, genetically speaking, completely identical down to the last molecule. By examining identical twins separated at birth, as well as identical twins raised in the same environment, behaviorists and psychologists have very reliably determined the effect that genes have on an individual’s eventual traits. For example, in the case of intelligence, genetic differences have been determined to account for only half of the variance in individuals. While this may at first seem like a high fraction, and it is considering most traits are only affected 5-10% by genes, this also means that environment accounts for the other half of variance. This proves that an individual’s environment is massively important in determining his or her level of intelligence in later life. Thousands of unpredictable forces—from interactions with others to events in the physical world—act upon our development and genotypes now. Take, for example, the trait of shyness as observed in a twin study: “Although one twin with a predisposition to shyness may appear passive all of his life, the other may try to compensate for that passivity by forcing himself into a setting that requires bursts of energy…a genetically predisposed pattern may appear in many forms” (Neubaurer and Neubaurer 106). How do engineered genes differ from these twins’ naturally selected ones? If germ-line engineering were to be implemented in the future, the “nature” side of human development may become engineered and predictable, but the “nurture” side of humanity’s development will remain unchanged. While germ-line engineering may provide an individual with the potential to become a genius, if this individual is not raised in an enriching environment, no extraordinary level of intelligence will arise.

Germ-line engineering is not a “magic bullet.” It does have its limitations. Many opponents to the technology often overlook this and exaggerate the abilities of the technology, ignoring the influence of environment on oneself and distorting the effect it will have on humanity. It will never be able to produce a person who is completely robotic or predictable, as most who object to the technology fear. It may produce a child who has long, nimble fingers, proficient hearing, and a tendency towards musicianship or one who has an especially efficient blood-oxygen exchange system and a talent for athleticism. Yet, germ-line engineering will be unable to compel these offspring to embrace their musical talents or embrace their athletic ability any more than our current “natural” genes can force us to develop our talents. As human nature stands now, we are already predisposed by our genetic makeup to enjoying particular things based on genetics as well as on culture and life experience. The factors which contribute to our realized personalities will not change if germ-line engineering were to be employed in the future and, in fact, only one of these contributors would be predetermined though the technology.

Take, for instance, the scenario of the child who has been engineered to be an exceptional athlete. Germ-line engineering would be able to produce a child who can run at previously impossible speed, but it will not make said child enjoy running or motivate him or her to develop their skill. Even today, the best of runners are not necessarily those who were born with the best ability to run. The best runners are those who train day in and day out, who dedicate themselves to the sport they love, and who push themselves beyond what nature has given them. In other words, the best runners are those who take what is given to them by nature and nurture this ability to be something more. This idea has been discussed and supported by the study of sports psychology for many decades. In the book “Applying Sports Psychology”, authors Jim Taylor and Gregory Wilson discuss the concept of motivation as a determinant of an athlete’s success, as well as one over which the athlete has power: “Motivation is a critical variable in an athlete or a team’s performance, influencing the amount of effort expended, the ability to remain resilient after setbacks, how long someone will persist during long and difficult periods of training and actual competition results. Motivation may be the factor over which athletes have the most control” (18). In other words, motivation can be the factor that makes an athlete successful or unsuccessful and is a factor controlled entirely by the athlete and his or her environment. Motivation is, therefore, the characteristic which must be nurtured in a child for their natural abilities to shine. Regardless of if an embryo was engineered by scientists to develop into an adult with extraordinary athletic skills, the embryo would have little potential to become a world-class competitor without also developing motivation throughout its life.

This is not, however, the only environmental factor that Taylor and Wilson identify as contributing to an athlete’s success. A second characteristic which they define as aiding natural ability is confidence: “Confidence may be the single most influential psychological contributor to success in sports. Athletes may have all the ability in the world to perform well and achieve their goals, but if they don’t believe they have that ability, then they won’t fully use that ability…It is often not their physical or technical capabilities but rather their belief in their ability [that determines success]…”(22). This is a widely held tenet of sports psychology, one that coaches, broadcasters, psychologists, and athletes alike have discovered and believe in. In consideration of the contributions such “nurtured” factors have on the performance of even the most able athletes, there can be little doubt that more than simply one’s genotype produces one’s eventual characteristics. Germ-line engineering opponent Bill McKibben claims: “As we move into this new world of genetic engineering, we won’t simply lose races, we’ll lose racing: we’ll lose the possibility of the rest, the challenge, the celebration that athletics represents” (6). Arguably, however, this is not the case. In today’s world, it is not the runner who is naturally fastest or who has the most efficient blood-oxygen exchange system that wins the race; it is the runner who is most dedicated, motivated, or confident. Thus it will not be the child with the most advanced genes who is the best runner. It will be the child who, throughout his or her life, developed the skills and traits necessary to become a good runner and dedicated him or herself to the task most wholeheartedly.

Just as genetic code is added to by an individual’s environment, it is often also subtracted from due to environmental factors. This is illustrated when considering the genetic disease, Phenylketonuria (PKU), whose phenotypic expression is dependent entirely upon environmental effects. PKU is characterized by an inability to process a common element in man’s diet, the amino acid phenylalanine, due to a defect of one enzyme. If an infant with PKU eats a typical diet, levels of phenylalanine will rise in the bloodstream until they reach toxic levels, producing mental retardation or death. If, however, the child with PKU is screened at birth (as is common practice in most developed countries) and his or her diet is modified to contain only the lowest possible levels of the amino acid, he or she will develop no symptoms of the disease and lead a completely normal life, as if the defective gene was nonexistent in his or her genetic code. Steen states, “Although this condition is quite rare, it clearly demonstrates that human traits can result from complex and subtle interactions between genes and the environment” (16). So, while germ-line engineering would code for particular traits, there is no guarantee or inevitability that these traits would be expressed at all by an individual throughout his or her life. With this technology, we will not produce the stagnant, hopelessly preprogrammed children that many rivals to genetic engineering fear, but ones with particular genotypes that may or may not come to be expressed phenotypically during our progeny’s lives. We will, however, be able to ensure that they are not plagued by potential genetic diseases such as PKU. This will eliminate the need to follow special diets to avoid a serious or fatal outcome which genes may produce.

In the same way that an individual is not a static creature, genes are not either. They can be expressed in many ways, determined entirely by the presence or absence of particular chemicals, stimulants, or situations. Thus, in addition to the environment’s effects on a gene being expressed or unexpressed, it can also have an effect on when and how that gene is expressed, producing various outcomes in an individual. “The genes send out new signals, makes new proteins, enzymes, and hormones, modify previous structures and functions, and trigger possible ranges of action. The environment influences this process, passively or actively, less of more, every step of the way” (53). For example, the conditions of a mother’s womb can have immense impact on an embryo’s development. While an embryo may begin development entirely normally, if incubated within a woman who abuses alcohol, the embryo may develop into an infant with fetal-alcohol syndrome, a debilitating condition caused entirely by environment that is characterized by morphological abnormalities and severe mental retardation. No matter how well chosen an embryo’s genes may be through germ-line engineering, if its mother cannot abstain from drinking alcohol in excess during her pregnancy, no amount of genetically encoded intelligence or handsomeness will be able to counteract the effect of the fetus’s exposure to alcohol.

In addition to the objection that germ-line engineering will produce robotic offspring, many challengers to the technology also fear that humanity will be robbed of its purpose were its genes preselected. There are countless proposed “purposes” or “meanings” for human life and nearly every individual has his or her own personal definition of purpose. I will focus on two of the most commonly designated ones: the search for self and pushing one’s physical limits. Germ-line engineering will not destroy these purposes, but alter them, ever so slightly. The latter of the two can be dismissed with evidence provided earlier concerning sports psychology. Limits are not set by genotype alone, but contributed to by such things as motivation and confidence. This meaning will, therefore, not be lost with the implementation of germ-line engineering. The search for self, also, is not a meaning that will disappear when one’s genetic code is manipulated. Opponent Bill McKibben claims that if we were to preselect our children’s tendencies, they would have no opportunity for this self-searching experience, as their identities would be laid out before them. He asks: “What will you have done to your newborn when you have installed into the nucleus of every one of her billions of cells a purchased code that will pump out proteins designed to change her? You will have robbed her of the last possible chance of understanding her life” (47). It is true that this hypothetical daughter’s genes will partially decree her future traits. However, our genetic makeup is not the only place from which our identities emerge. This, again, comes down to the debate over nature versus nurture. Well-known eighteenth century philosopher John Locke was an emphatic proponent of the importance of environment on the development of human beings: “Locke judged the bulk of human variation to be the result of differences in experience: ‘I think I may say, that of all the men we meet with, nine parts of ten are what they are, good or evil, useful or not, by their education’” (Loehlin 1). In other words, man is taught throughout his life to be gregarious or withdrawn, ambitious or unmotivated, steadfast or flighty. So, regardless of if the “nature” portion of our development is predetermined, the “nurture” portion cannot be predetermined or predicted. Humans will continue to have the opportunity to search for their identities even with the implementation of germ-line engineering and may, perhaps, even find new meaning in exploring how their environment has impacted their preselected genes to produce unique and unpredictable human beings.

As the width of these arguments exemplify, it is likely that the debate over the merits and drawbacks of germ-line engineering will continue on into the future, as there are countless arguments that can be made for both sides. The claim that germ-line engineering will rob future generations of their identity or meaning in life, however, is not a valid one and not an argument that should continue. The overwhelming evidence, from centuries of observation and decades of experimentation, demonstrates that environment wields enormous power over an individual’s eventual characteristics, both physically and abstractly. Predetermining an individual’s genetic makeup will not, as many opponents to the technology argue, produce an utterly static individual with no ability to differentiate from what a scientist determined, living life with no ability to choose and lacking an identity or meaning. Steen sums the control of genetics on the individual brilliantly when he states: “While DNA may decree destiny, the destiny it decrees is apparently not a fixed and immutable one” (1). DNA, whether passed naturally from parents to child or composed unnaturally in a test tube, does not dictate the specifics of every single characteristic or trait or action an individual has or takes, but affects these things in conjunction with the environment of an individual in countless unpredictable and interesting ways.







REFERENCES

Hettema, Joop and Ian J. Deary, eds. Foundation of Personality. Boston: Kluwer Academic Publishers, 1993.

Loehlin, John C. Nature–Nurture Controversy. (2004). In The Concise Corsini Encyclopedia of Psychology and Behavioral Science. Hoboken, NJ: Wiley. Retrieved March 02, 2009, from http://www.credoreference.com/entry/4410575

McKibben, Bill. Enough: Staying Human in an Engineered Age. New York: Times Books, 2003.

Neubaurer, Peter B. and Alexander Neubeurer. Nature’s Thumbprint: The New Genetics of Personality. New York: Columbia University Press, 1996.

Steen, Grant R. DNA and Destiny: Nature and Nurture in Human Behavior. New York: Plenum Press, 1996.

Taylor, Jim and Gregory Wilson, eds. Applying Sport Psychology: Four Perspectives. Champaign, IL: Human Kinetics, 2005.