There are multiple problems in your argument:
> similar results in Germany
First, I can't find any stats online that claim marriage rates in Germany among Black communities are identical to marriage rates in the US. Maybe you do have a source, but you need to be more specific if you're going to make claims like this.
I also can't find any stats online that claim that wealth inequality in Germany is identical to wealth inequality in America. This would be a really good thing for you to cite, because your whole argument seems to be that there's something inherent in the Black community that means it will make less money no matter where it goes or what the context is. If Germany doesn't have comparable wage gaps to the US, then we don't even need to continue with the rest of your comment.
> and Germany does not share the US' history of slavery.
Second, can you think of any event that happened in Germany that might have had bad outcomes for Black people? Maybe one that happened during the 1940's? Do you know the date that Germany's current constitution was ratified? How can you possibly say with a straight face that Germany has no history of racism?
Germany's history with racism was different from the US, and we'd expect that to manifest in different ways. We don't expect racism in Germany to look identical to racism in the US. But WW2 was recent, my own grandfather fought in WW2. We're barely a full generation away from a Germany that was trying to exterminate different races.
> The socio-economic inequalities are just as well explained by cultural differences though
It's poor reasoning to assume that Black communities are a monolithic culture with the same beliefs and behaviors everywhere in the world. Are you really saying that German wage gaps were caused by the way Americans halfway across the world raised their kids in the 50s and 60s?
It's also kind of interesting that you assume Black culture would be the same across multiple continents, backgrounds, and national origins, but that you don't assume the same of the treatment of Black people or the attitudes of the cultures that surround them. There's a lot of inconsistency here, and you need to decide whether or not you really believe that all countries are homogeneous.
Unless you're claiming there's a genetic factor at play, but I'm sure you wouldn't claim that, right?
> that it doesn't affect all Black people, but filters by ethnicity
Are you trying to say that results that vary greatly depending on ethnicity can't possibly have racial factors at play? The way that people experience racism differs depending on both their origins and where they live.
> A generation later, they're hard to distinguish from the native population with regards to education, have low unemployment and are creating moderate wealth
I know people like to hold up Germany as an inclusive utopia, but Germany absolutely does have a problem with people being racist to immigrants, and not just Black immigrants. Germany's past with racism is different from America's and the outcomes aren't identical. But this completely rosy view of immigration in Germany that you're pushing just isn't true. If you read actual reports of immigrants to Germany, they do struggle with racism and cultural alienation.
> Poverty doesn't really work as an explanation for delinquency either.
Finally, you will be hard-pressed to find any serious study about divorce that doesn't mention money as a contributing factor. I don't understand how anyone could claim that poverty doesn't have an effect on family/childhood statistics.
You want to talk about conspiracies, then which scenario is more likely? That all of that research is wrong and all of the sociologists are being paid off? Or that there are some additional contributing factors in Germany that you don't understand?
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So the TLDR is I can't find any stats that confirm what you're saying, even if I could find stats that confirm what you're saying I don't think your logic about how culture works is internally consistent, there are also events in Germany's past that would partially explain wage gaps (assuming your claims about those gaps are true), and Vietnamese and Asian communities do experience racism, including in countries like Germany.