That would not be enough control if IQ has influence on whether someone marries their cousin.
Are you arguing for the sake of arguing a methodological point, or do you seriously think that this point has a >50% chance of making the theoretically predicted and empirically confirmed phenomenon of inbreeding depression just go away?
A thought occurred to me today as I skimmed an article in a rationality forum where the subject of gay marriage cropped up; seeing as the issue has been hotly contested in various public fora and especially the courts, what about poly? After all, many if not all the arguments for gay marriage apply to poly marriage as well.
Questions for LWers who are currently in a such a relationship, or have an opinion to share:
Do polies want to marry each other or do such relationships not lend themselves to permanence above a threshold of partners? Should polies campaign for the right for a civil union anyway? what are the up and down sides of this? etc