Yes, that study was linked to the documentary I posted.
Per my other posts, you can never “stop” anything taking place entirely, but by outlawing it you significantly decrease its incidence. In the case of marriage we can stop cousins marrying entirely: we simply prohibit it and do proper checks when people apply for a marriage licence, as we do already to ensure they are not siblings. And we require the same evidence to prove that their marriage is valid under UK law and not a “cousin marriage” to recognise in the UK any marriages that took place in other countries, including when it comes to visa applications/ family reunification (an ironic term, in such cases, given how often this is the motive for such “marriages”, often in exchange for money).
And when we finally prioritise science over people’s medieval “cultural practices” and recategorise this as incest, with the prospect of a 7 year prison term for those convicted, this will obviously significantly reduce the number of people prepare to engage in this activity, which more often than not is not something the women involved would have chosen freely and have been coerced into doing, and obviously has completely unnecessarily appalling outcomes for a significant proportion of their children as well as them.
I.e. Making these legal changes will have a very beneficial impact on society, reduce human suffering (particularly of women and children) significantly over time, reduce the levels of completely unnecessary and avoidable severe disability and painful/ life-limiting medical conditions in our population, reduce abuse of women, increase average IQ, reduce the number of birth defects per capita, encourage more integration between communities perhaps (or at least within them, reducing the tribalism in some backwards isolationist communities in the UK), make it clear that science and evidence-based policy is the UK priority not pandering to medieval traditions which have been proved to be harmful, reduce abuse of our immigration system and using women as a tool to do this often by effectively “selling” them to extended family from which they then cannot possibly escape because who can they go to for help when their parents are the siblings of their abusive “husband”’s parents and ordered the marriage in the first place?
And the drawbacks to making cousin marriage illegal and adding sex with a cousin to the legal definition of incest would be….
very little at all, especially over the longer term.
It’s literally a no-brainer for anybody who has the faintest grasp either of the genetic/ statistical/ medical facts, or of the abhorrent motivations of those who continue to enforce this “tradition” on women (and men, but mostly women) the majority of whom would not choose this freely without family coercion. Why would anybody? Basics genetics are taught in compulsory education as part of the national curriculum to the necessary extent for it to be blatantly obvious that marrying your cousin is not just quite a repellent idea but also highly likely to cause immense genetic problems for your descendents.