It is mostly accepted that several human species lived together at the same time, long in the past. Eventually all the others were killed/died off and we are left with only homo sapiens. But perhaps, in an alternate world, more than one human species survived to the modern world, living alongside us.
Would this world be more, or less united than today? If we had entire other species of humans that we couldn’t even breed with, would we be united as homo sapiens, regardless of race or religion, and have all our fear and hate focused on the other species? Or would we be even less fearful of ‘outsiders’ after living with them for so long?
It would certainly be harder to have the ‘humans are special and better than everything!’ attitude when there is an entire other species just as smart and capable as yours. And that could only be a good thing…