Hich process involves unifying various social groups into one society?

This process is called social integration.

Social integration is a process during which newcomers and minorities are incorporated into the social structures of their host society.

Social integration means accepting local costumes and daily practices of the new host. The host can be a new country, a new workplace or a new school.

Social integration starts with accepting the fact that some changes and adjustments are necessary, it also means an effort to combine and prevent one own's identity with the identity of the new host.

This process can not be forced as the groups being integrated have to want it in the first place. Failing to integrate into a society can cause social exclusion and polarizations

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