I suspect the biggest difference might be between one-to-one and in-a-group. In a group, other people will move the conversation in ways that distract from one person finding out the reasons why the other person holds the views he/she does.

Unrelatedly, in a group, the returns to signaling that you dislike the hated outsider are much higher, as are the costs that come with treating hated outsiders like neutral people. See also: Twitter dynamics.