The
paper referred to here from Harvard (based on 20 years of reseach) is interesting.
"Recent events have intensified concerns about the integration of Muslim populations... For some observers, disaffected Muslims in France, the UK or the Netherlands are seeking to create a society entirely separate from the mainstream... The analysis [in this paper] demonstrates that the basic values of Muslims living in Western societies fall roughly half‐way between the dominant values prevailing within their countries of destination and origin.
This suggests that migrant populations living in Rotterdam, Bradford and Berlin are in the process of adapting to Western cultures...