Over at Reason, they highlight the work of a bioethicist who is arguing that modern potential parents should “screen out” potentially negative genes found in the DNA of their embryo. (It’s unclear as to whether “screen out” is a polite way of saying abortion, or whether what’s being suggested is some kind of embryonic gene replacement.)

The argument, as I understand it, goes something like this: as time passes, we will be more and more capable of identifying genes (e.g. chunks of DNA found in our chromosomes) associated with certain behaviors. If a pregnant couple look at the DNA of their embryo and see something like a gene for psychopathy, shouldn’t they address the situation in some way?

Here’s the bioethicist himself (from an article linked at the Reason page):

“Indeed, when it comes to screening out personality flaws, such as potential alcoholism, psychopathy and disposition to violence, you could argue that people have a moral obligation to select ethically better children.

“They are, after all, less likely to harm themselves and others.”

“If we have the power to intervene in the nature of our offspring — rather than consigning them to the natural lottery — then we should.”

The whole thing, of course, smacks of eugenics. Having said that, I don’t find myself particularly opposed to the notion. And I suspect that modification of genes and how these genes get expressed is going to become more and more feasible as time goes on, through processes that can be applied both pre-and post birth. For example, the whole idea behind gene therapy is that we can swap out genes in actual people (e.g. not embryos.) Right now the focus is on fixing genes that cause diseases, but why not use therapy to fix genes which might make someone more prone to alcoholism or anxiety? (Having said that, gene therapy is still in the early stages and to my knowledge hasn’t really proved itself.)

There are several caveats. For one, pretty much everyone agrees that a person’s personality and biological state are affected by more than just genes; environment is a big factor. Secondly, as the author of the Reason piece makes clear, genes can be a bit two-faced, and have both good and bad sides.

Savulescu’s vision strongly depends on the notion that genetic traits come in nice little packages that can be added or excised at will. However, behavioral “traits” are likely to have two (or more) sides to them, e.g., bravery could well be associated with aggressive tendencies, or prudence with selfishness, righteousness with implacability, etc. Can’t bioengineer away the bad without also affecting the good.