I have no data on this and am subsequently writing this completely off a hunch so excuse me if I am wrong here. This post is a thesis on how re-plotting people from different countries and families together can cause a lot of friction for community cohesion and people in terms of romantic relationships.
The idea is that if one takes someone from country X and moves them into country Y, say at a young age then the person moved will be more adapted to the new countries people and their pheromones than the other way around. Now how that could play out is that the immigrated child will be romantically interested in a local but that will not be the other way around as the local child’s pheromones are less tuned to the immigrated child’s ones.
This friction can be reduced by having only international schools with a lot of diversity and interaction between the student body however our biology clearly changes at a slower pace than our culture. Cultural assimilation can happen within a generation if not within years.
Maybe as written before, slow progress is better than no progress or too quick… now measuring and determining the optimal rate may be something for someone else or something (AI) else to figure out.