[Edit: I say the following with some caution cause I read most of this study, but not all of it]
Of course dialogue can be a great tool for conflict resolution between two people with very different worldviews.
This study seems to me me to have a twisted approach tho. For example the problems between Mexican immigrants and white Americans, are not a result of lack of dialogue between themselves.
Their problems are the result of policies that have been present for such a long time and are made by other people higher up in government positions, implemented by law, police, armies etc. For me, failing to take these dynamics into consideration in a study like this can only provide misleading conclusions that exempt authorities from their responsibilities in creating and/or maintaining these dynamics.