I think there can be different things going on under the hood.

Some people will be self aware, and not take arguments or positions too seriously - their own or others - they know they hold the points of view for group membership - they tend to not to like to debate them, aware of the futility.

More common though is ego-defense/group-defense reaction. This is the zealot. Both a person's ego (you're wrong) and their group (your group is wrong) is on the line. This is in addition to losing their membership of a group if they adopt a different position.