The ethics of sleeping at night

My last post was about one small point in the relationship of evolution to ethics. I pointed out that evolution and ethics don't even apply at the same level, so it is invalid to extrapolate from one to the other. There are many other problems with the application of evolution to ethics, and I would like to use a sinple example to show some of them here.

The public understanding of the relationship of genes to behavior and ethics is often confused, and this affects many discussions of behavior genetics, ethics, and sociobiology. I deal with college students, and probably about half of them do not initially understand what it would mean to have a genetic component to behavior. I think the example of our diurnal circadian rhythm is a familiar example that nicely clarifies these misunderstandings.

One common misperception is the belief that genes are destiny. If there is a genetic component to a behavior then you somehow lack free will. Criminals could be excused because their genes made them do it. Also, people often perceive genetic control as being specific, affecting particular behaviors rather than overall tendencies. Since most people see their behavior as being under their control and do not think of themselves as robots, they cannot see how genes could affect us.

Diurnal behavior is something everyone is familiar with. We all know that we sleep at night and are active in the day. Almost everyone recognizes that this is part of our biology. We do not choose it. We could not just as easily become a nocturnal society. Clearly, genes do affect this particular behavior (we even know a few specific genes involved in this, such as the per gene). At the same time, it is not destiny. We can stay up all night. Those that work night shifts can even become reasonably well acclimated to different hours. We still have free will.

This also shows genes do not affect specific behaviors but instead just affect tendencies. There are examples in other species of genes producing a specific stereotypical effect, such as the courtship dances of fruit flies. But genes do not seem to work this way in humans (there are a few syndromes and pathologies that produce stereotypical behaviors in humans, such as obsessive compulsive disorder and others, so it is not inconceivable in humans, but it is not the rule.).

The other misunderstanding is how genes relate to ethics. Just because we have genes to be diurnal does not mean that we should behave that way. Most people do not think it is immoral to stay up late or work the night shift. The fact that we have genes for being diurnal says nothing about the ethics of that behavior. That is obvious for being diurnal but people often are unable to extend that to other behaviors. If genes influence our sexuality or a tendency to alcoholism, the fact that it is genetic is still ethically neutral.

If the presence of the gene does not dictate how we must behave, then how the genes arose through evolution and the selective pressure for the genes says even less. Evolution can only account for genetic characteristics. All of the things that are caused by the environment or choice are not affected by evolution. And if a gene does influence a particular behavior, I do not see how it matters at all whether that gene arose by evolution or was instantly created 6000 years ago.