Good reminder! We generally behave in ways which are in accord with our attitudes and beliefs, but often the best way to break through the barrier is not verbal, but putting a person into a situation where another kind of behaviour is not only possible, but eminently reasonable.
The well known experiment of 30-odd years ago in relation to race prejudices in the United States is instructive. A well dressed, well spoken Afro-American presented at hotels to take up a phoned room booking. In most cases, hotel owners accepted the guest -- he was outside their mental picture of an Afro-American, on which their race prejudice was based.
It breached the citadel of their prejudice.