What assumptions are made by colonials about the native peoples?

In Wole Soyinka's play "Death and the King's Horseman" the colonials, best represented by the character of Simon(and his wife Jane) Pilkings, does not understand the culture or the people of the African colony where he has been sent to govern.  He, and the other British citizens there, are convinced that their ways are civilized and that anyone should want to adopt those ways and customs. He does not understand their traditions or their religious beliefs or that they can believe as strongly in their own way of life as the British do in theirs. Moreover, he insults them by making a mockery of their traditional dress and cultural practices. Soyinka is demonstrating what actually happened to the peoples that the British conquered. It was always their assumption that the natives ought to be grateful and would be happy to give up their barbaric lives and traditional practices for the ways of the Empire.