The inter marriage, linguistic and cultural borrowing were brought about by human migration.
Hence, inter marriage fusion existed among people as a result of the movement of people from one place to another i.e. one geographical zone to another, one state to another; one community to another, ethnic group to another etc.
For instance, the Jukun people intermingled with the Chamba and the Bata, thus, resulting in cultural diffusion.
Again, the Itsekiri kingdom developed out of Benin, Ijaw, Urhobo and Yoruba and that gave rise to a society with a language similar to Yoruba.
Hence, the linguistic similarities were on the high side then among the people. Another instance was that due to the fact that the Benin people historically related with the lfe people, both Bini and Yoruba languages were spoken by the Binis. Even today, some Igala people in Anambra State (Idoma, Nzarn, Igbedo) share both Igbo and Igala languages.
Moreover, the Ijaw fishing people of the Delta, people from the Cross Rivers and the Itsekiri people intermarried and the result was cultural fusion that later gave birth to distinct societies.
On the other hand, there existed cultural relativism among people before the 1800 Nigeria’s history.
This was exemplified in the Ekwe masquerade of Igala which traditionally belonged it the people of Jukun. Again, there were resemblances in ‘the Jukun masquerade with those found in Igbira, Idoma, Igala and Oworo of the Niger-Benue confluence area.
In furtherance, the wooden figures (Ikenga) in Igbo and that of Igala people bore the same structure.