Imagine a world in which genetic interventions (for hair/eye colour, health, strength, happiness, morality…) were tested, safe, effective and accepted. In this genetic supermarket, who should be allowed to buy – to decide how children should be modified? Parents seem the obvious choice – but on reflection, there seem few reasons to allow this.

Why is it good for people to make their own choices? Firstly, out of liberty: everyone should have the right to do what they want with themselves. Secondly, because people know their own preferences much better than anyone else (one of the reasons that the communist command economies failed). And thirdly because people can experience the consequences of their choices, and become more skilled consumers, driving poor products out of business.

None of these applies to parents choosing their children’s genes. Here they are making the choice for other people, whose preferences they don’t know (because they don’t even exist yet!). And unless parents plan to have ten or twenty children, they have no relevant personal experience to draw on for comparing genetic interventions. And the main effects of these interventions are very long term, making the parents even less suited to making the choice in an informed way.

But don’t parents presumably love their children, and want what’s best for them? Well yes, they do (or should). But for most interventions, a faceless bureaucrat following simple procedures would be just as good the parents! This is because average parents have no skills at determining the effect of genetic interventions. So they have to follow expert verdicts on effects. And bureaucrats can follow expert advice just as well as parents can.

If there are no tradeoffs, then the result is clear: if intervention A would result in child that was more intelligent and happier that intervention B, then the bureaucrat can choose A as well as a parent can – and there is no reason to allow parents to choose B!

If there is a tradeoff – intervention A makes happier children, intervention B makes then smarter – then parents are back to making difficult choices for other people. The fact that parents love their children is immaterial: is it the parents who choose A who love their children, or is it the ones who chose B? Presumably, both: so how is parental love relevant to the choice?

Maybe parents feel that certain interventions are more compatible with how they plan to bring up their children. But since most interventions are long term and most parents have very few children, there is no reason to suspect parents are correct in their feelings. Maybe there is an implicit quid pro quo: parents will only accept to have children, if they can shape them in certain ways. This is possible, but it’s ultimately a selfish argument.

Two arguments for parental rights do seem somewhat stronger. Maybe the parents are members of a particular cultural or ethnic group (such as the deaf community), and plan to bring up their children within it. And then there’s the whole issue of “if not them, then who”? If parents don’t get to decide, the most likely alternative is a governmental entity. It might be worth taking a stance against governmental power here, to deny them the power to shape the next generation (though most governments aren’t long term focused enough to worry about something four election cycles away).

In practice, though, we’ll likely end up in the usual equilibrium: with the government setting the general parameters (minimal health and happiness), and parents making choices among the government-allowed options.