The Measure of a Man
Elizabeth Mumford
With advances in genetics and the decryption of the human genome, many people are taking the time to sit back and ponder the questions of what humanity is and where it comes from.1 Will techniques such as gene therapy eventually create people who aren't quite human? If humanity is a flexible and ever-changing concept, then how do people know if they are human? Does some standard measure of humanity seem likely in our future, and is it even ethically proper to impose such a standard?
Philosophy offers the most satisfying definition of humanity: a human person is a conscious individual who interacts with an outside world. The details of the various philosophical debates on the exact nature of personhood would be enough to fill a library, but the main ideas can be summarized as follows: a person is self-aware, having the ability to think about thinking. Nothing in this definition of humanity involves matters of genetics or quantitative analyses of specific traits, which makes this definition applicable to people who may not be human in the way science tries to define the term.
Defining humanity in a scientific sense, however, is a nettled endeavor. Many "strictly human" traits can be found in animals. Wolves have a complex social structure. Bonobos, a subspecies of chimpanzee, can learn an abstract symbol-language and show the ability to understand grammar and syntax.2 In other experiments dolphins-who are genetically more distant from humans than bonobos-learned a type of sign language showing that they, too, are able to grasp complex rules of language.3 One only has to yell at the family dog to see that animals can express emotion and empathy. What, then, is left to humans?
Many point to our advanced technology as proof of our uniqueness, but it is well known that chimpanzees use tools on a regular basis. The only difference in this instance is that chimpanzees don't need to have very many advanced tools-they are more suited to their environment than the researchers who must carry around thirty pounds of gear to study them.
Despite evidence to the contrary, many people still cling to the belief that humans are somehow superior to all other organisms-this innate superiority being the essence of humanity. Humans are, after all, the most successful large animals on the planet, having spread to every continent and taken control of the ecosystems there. However, it could be argued that certain kinds of bacteria are more highly evolved than people-their genomes do not contain long stretches of "junk DNA" and their genes are organized into related groups more efficiently than the genes of most eukaryotes, like humans.4
The fallacy in the idea of human superiority is that most people assume that evolution is some sort of race: organisms compete with each other to be the most successful species of all, an "ultimate organism." "Evolution has no pinnacle and there is no such thing as evolutionary process."5 The truth of the matter is that there is no over-arching competition being held; creatures simply change to be better suited to their environment. Humans are not necessarily on the top of the heap-humanity just happens to have the advantage over other large animals. One only needs to look at the cockroach to see the same evolutionary success.
Intelligence is cited by many as the main defining characteristic of humans: humanity is somehow rooted in the ability to solve problems and manipulate concepts in the mind. Unfortunately, intelligence is also extremely hard to define and quantify reliably. Many early IQ tests were biased so that people with western, middle-class values scored highest.6 The more recently revised IQ tests do not accurately measure a person's full intelligence, since intelligence can be described on a variety of scales and some people do better in some areas than others-leading many psychologists to accept a theory of multiple intelligences.7 If a concept as clear-cut as intelligence cannot be measured by science, a philosophically nebulous concept such as humanity is equally unmeasureable.
Many theologians would argue that the defining characteristic of humans is their possession of a soul. In 1996, the Catholic Church was able to reconcile evolutionary theory with church doctrine by arguing that at some point, called the "ontological discontinuity," God injected a soul into the ape lineage and thus created man.8 Is the soul some sort of physical process or hidden gene? There is no real evidence to support this. The only major genetic difference between humans and primates is the fusion of two smaller ape chromosomes into our chromosome two.9
Chimpanzees share at least 98 percent of our genes (estimates vary). Could a soul lie in that measly two percent? Again, philosophy and theology, not science, are the forerunners in defining humanity. Psychologists regularly use animal models to test mental processes that occur in humans. Neurologically speaking, our thought processes are nothing special, and human consciousness has yet to be satisfactorily explained by science. If human thought is basically the same as animal thought, then how can a 2 percent change in the genetic code between humans and their closest animal cousins account for culture, the arts, and science?
What, then, can be measured as a determining factor of humanity? Scientifically speaking, there are no real hallmarks to humanity-nothing that can be definitively quantified. The closest definition of humanity is religious or philosophical, not genetic. People must figure out for themselves if they are human or not, and perhaps this is a good thing. Self-awareness is currently the only hallmark of humanity, something that all people are demonstrated to have. Should humanity ever become a known quantity, what would happen to the inevitable exceptions to the rule? Many such thought-experiments are carried out in science fiction, but there are plenty of dilemmas in current real life to illustrate this problem.
As genetic engineering advances, there will inevitably be changes in the human genome. For good or ill, gene therapy could eliminate certain unfavorable traits from the genome forever. Could the recipients of gene therapy be considered less human because of the artificial changes in their genes? What about people who have a genetic disorder yet cannot afford genetic alterations? The number of chromosomes a species possesses is one of the few hard-and-fast genetic measures of identity, but people with Down's syndrome have one more chromosome than most people. Does that make them some other species and therefore not human?
Scientifically, the only real distinguishing characteristic of humanity is that we all belong to the species Homo sapiens. However, even the idea of species is nebulous. The most popular definition of a species is called the biological species concept, which states that a species is "a population or group of populations whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring, but who cannot produce viable, fertile offspring with members of other species."10 At first this seems like an acceptable definition-you can't breed housecats with tigers, let alone get offspring, but you can breed housecats with other housecats.
On second thought, though, there are problems with this definition of a species. A Chihuahua and a Great Dane are both members of the species Canis familiaris, the domestic dog, but it is impossible for the two breeds to reproduce with one another without intervention, by taking the operation out of nature and using techniques like artificial insemination. When left alone, a dog as small as a Chihuahua simply cannot mate with a dog as big as a Great Dane. Does this make Chihuahuas and Great Danes members of separate species? What about infertile couples, who cannot have children of their own, or cultures who do not intermarry outside of their own group? Does this make them a separate species? The answer is no, but if science cannot clearly define taxonomy, how can it seriously address more complex issue of humanity?
Ethically, anyone confirming substantially to the current nebulous ideal of humanity is considered human with all the rights and privileges thereof. If there were a score or a standard, the result of any scientific measure of humanity, then would people who would otherwise be defined as human become sub-human or super-human? Humanity itself could become stratified into classes just as economic status is, with all the resulting prejudices. Ethically speaking, a scientific measure of humanity could easily cause more harm than good-a situation such as the Holocaust, in which millions of people were killed because they didn't measure up, could happen all over again.
This theme is treated often in science fiction. In the movie Gattaca genetic engineering had advanced to the point that parents could select all the qualities their children would have. Anyone born with a genetic defect was then relegated to the fringe of society to serve the more perfect members of their race. Historically, this sort of stratification took place all over the Western world, as Europeans and Americans subjugated peoples from cultures considered less human. The flip side of the issue is presented in the comic book series The Uncanny X-Men (in its various incarnations). In the series, an average human society persecutes the genetically superior human mutants because it fears their power (though with just cause; certain groups of mutants occasionally try to subjugate the relatively defenseless masses). In both of these fictional case studies, rampant prejudice forced people who did not live up to a certain quantified definition of humanity to live in perpetual servitude or fight for their lives.
In conclusion, a genetic definition of humanity will probably never be found since humanity itself is a nebulous concept that is subject to change according to culture and time period. This, of course, will not stop science from searching. However, in the ethical larger picture, searching for the scientific root of humanity may not be as good an idea as originally thought. As Ian Malcom put it in the movie Jurassic Park, "They were so preoccupied with whether or not they could, they didn't stop to think if they should."
Notes
- This paper was originally written for Professor Rosemary Ford's CNW course, "Human Genetics, Society, and Ethics," held at Washington College, Chestertown, Maryland.
- Robert A. Baron, Psychology 5th ed. (Boston: Allyn and Bacon, 2000).
- Baron.
- N. A. Campbell, J. B. Reece, and L. G. Mitchell, Biology 5th ed., (New York: Addison Wesley Longman, 1999).
- Matt Ridley, Genome: The Autobiography of a Species in 23 Chapters (New York: HarperCollins Publishers, 1999) 24.
- Ibid.
- Baron.
- Ridley, 24.
- Ibid.
- Campbell et al., 446.
Bibliography
Baron, Robert. A. Psychology. 5th ed. Boston: Allyn and Bacon, 2000.
Campbell, N. A., J. B. Reece, and L. G. Mitchell. Biology. 5th ed. New York: Addison Wesley Longman, 1999.
Ridley, Matt. Genome: The Autobiography of a Species in 23 Chapters. New York: HarperCollins Publishers, 1999.