The crime of incest currently includes not just siblings but parents, grandparents, aunts and uncles. It would not be remotely difficult to extend this to cousins as well. It would make it much easier for women to get help when subjected to these unwanted “relationships” or “marriages” by coercion because coercion/ rape are hard to prove but proving someone is your cousin is very easy.
The laws prohibiting incest function perfectly well so simply extending them, based on the scientific evidence, to cover cousins as well is a simple amendment of a few words to the existing law. Then, when this behaviour is likely to carry a prison sentence of up to 7 years far few people will engage in it in the first place, and in those cases where people do it will be far easier for women (because it is mainly women who are coerced into it) to go to the authorities, get moved to a refuge away from their abusive families if necessary, and have the perpetrators prosecuted.
It isn’t “a minefield to detect” any more than the current categories of incest set out in the law, and the more pertinent fact is that it provides women with proof that they are being treated in a criminal way rather than them having to prove coercion/ abuse/ rape/ forced marriage, which is much harder if their family all support each other and lie about it.
Of course it’s disgusting for people to be incestuous. The natural aversion to this, just like the other instinctive human disgust mechanisms (e.g. our aversion to rotting organic matter, the smell of food that has gone off, mould, etc) have developed precisely to protect us from illness and disease. This is no different. However, since there are clearly cases where the natural aversion isn’t enough to deter people (as with other crimes like murder, GBH, child abuse etc) we have laws to ensure that those who have the propensity to overcome the natural aversion to such damaging behaviour are prevented from carrying it out to the greatest extent possible, to protect their potential victims and wider society.
Genetic counselling and education has not reduced this abhorrent behaviour significantly enough to be acceptable despite this approach being used for decades now. The rate of occurrence will be decreased far, far faster by taking the simple steps of refusing marriage licences to first cousins and adding sex with a cousin to the definition of incest in law. We also know, for the reasons explained in detail earlier in the thread, that even detailed genetic testing (let alone “genetic counselling”) cannot sufficiently reduce the unnecessary risk posed by cousin marriage because many of the conditions causing the birth defects are not testable, so that is not a solution. There is a very simply solution that involves no significant restriction on anybody’s civil liberties and would instantly reduce immense deliberate harm needlessly being caused to innocent children, as well as reduce abuse of women as a side-effect, and cut the immense cost of this appalling behaviour to the state.
Why would we not make it illegal when the evidence of the benefits of doing so are so clear and there is no drawback whatsoever from doing so?