So by "homogeneous" you don't really mean homogeneous, you mean upstanding people who don't commit a lot of crime or problems?
Eastern Europe is much more homogeneous than western Europe, there is also more crime and problems there, so I don't see a strong link between the two at all.
I think it's both. If you have two communities that believe they are acting in an upstanding manner, but both have different values, then neither trusts the other.
I do also think though that some cultures, religions etc have "better" moral standards.
Eastern Europe is much more homogeneous than western Europe, there is also more crime and problems there, so I don't see a strong link between the two at all.