Migration played important roles in promoting inter-group contact in Nigeria.
First, it led to the fusion of culture Nigerian people and as a result, people mingled with each other and shared similarities in language and otherwise.
Secondly, Slave raiding and warfare in many occasions forced people out from their original settlement to other places. Hence, after various wars, many people were captured and taken prisoners or sold into slavery. And as vassal states, they were forced, to be subjects in the foreign land.
Moreover, migration played important role in the aspect of religion. For instance, Muslim migrants exerted social, educational, spiritual and moral influences on the Yorubas and the people of southwest Nigeria.
Again, war and constant disputes led to the depopulation of regions (e.g. the middle belt area)
Furthermore, politics also played very important roles on inter-group relations in Nigeria. Thus, political instability in some areas led people to migrate to other areas where there was political stability; at least to have rest of mind there