1. mixed race children are less genetically similar to their grandparents than their grandparents are genetically similar to random strangers belonging to the same race as their grandparents
https://en.wikipedia.org/wiki/Fixation_index#FST_in_humans
https://link.springer.com/article/10.1023/A:1020815420693
I don't want want to give my parents grandkids that they have no more genetic similarity to than a random stranger.
2. what if they're like elliot roger?
3. mixed race people are more likely to be liberal
https://mixedracefaces.com/home and so more likely to be low fertility
https://ifstudies.org/blog/the-conservative-fertility-advantage so your genes are more likely to dwindle to nothing rather than grow in number each generation
4. mixed race people more likely to have an incoherent sense of identity and not feel like they belong anywhere, more likely to have mental health problems
https://www.sciencedirect.com/science/article/abs/pii/S0165032723014088