Very often lately I have come across the Genetically Identical Anecdote. You've heard it -- this is the argument that a human is 97% genetically identical to a chimpanzee, or an orangutan, or a dolphin, or whatever animal species happens to be of interest at the moment. Usually the statement is made by a naturalist or environmentalist who wants the stress the point that humans are closely related to animals, or that humans are no better than animals. The argument, while a little jarring, is nonetheless scientifically true: Over 97% of the genes found in the chimpanzee can also be found in our own genomes.
I consider myself an environmentalist, and do not object to people pointing out our kinship with them. But Genetically Identical Anecdote has been overused, and the observation now seems stretched. Most of all, I am bothered by its underlying assumption, that genetic similarity necessarily equates with identity. Genetics, by its very nature, implies a biological determinism. But while many of our characteristics certainly are genetically determined, it is important to note the biological research is now showing that our genetic codes are not necessarily the unalterable script of our lives. There may yet be room for free will after all.
Some genes are expressed only with the right environmental stimulation. For example, you may have genes that help your brain respond to and analyze music. However, if you never hear a musical instrument in your lifetime, these genes may never activate. On the other hand, if your parents drag you to every opera that comes to town, or if you choose to educate yourself in music as you grow up, this stimulation may trigger these genes to express themselves, and you could develop a musical talent that you otherwise would not have had. There is clear evidence that what you are in part is determined by what you expose yourself to. Thus humans, while 97% genetically the same as chimps, nonetheless are different not only because of the 3% genetic difference but also because as humans we expose our genomes to all kinds of stimulations that chimps can't.
There is another problem in the heart of the Genetically Identical Anecdote, and this problem lies with the scientific tendency to stress quantitative versus qualitative observations. It is axiomatic that scientists like to measure things. Scientists are very good at drawing conclusions about observations that can be easily measured, and not so good at evaluating observations that are subjective. It is well known, for instance, that the human body is about 60% water by volume. Yet it would be absurd to conclude from that that a 100 pound woman is 60% identical to a 100 pound bucket of water. Absurd but quantitatively accurate. What makes the woman different from the bucket of water is primarily qualitative, that is, subjective. You cannot put a number or a value on the distinction, but it is bluntly obvious.
In the same way, the Genetically Identical Anecdote stresses what can be measured, genetic material, and ignores what cannot, clear subjective differences between ourselves and other higher primates. While the Anecdote is clearly scientifically accurate, repeatedly stressing it tends to reinforce an argument that may not be true -- that our genes are the only things that make us what we are.