Joseph Epstein has a wonderful piece in the Wall St. Journal today. Although he was writing specifically about politics, his point applies very well to religious discussions.
The subtitle of his article is "Our self-image is no so bound up in ideology that any disagreement feels like a personal attack."
Think of a missionary sharing the gospel. Many investigators will take the mere existence of a missionary from another church as a criticism of his/her own beliefs. Because our self-image is "bound up in ideology," the investigator may feel offended (or personally attacked) whenever the missionary offers a "better" religion, such as the "fullness of the gospel" which implies the investigator doesn't have the fullness. The missionary may feel personally attacked when others oppose what he/she is teaching.
Even within the Church, people conflate their ideological beliefs with their self-image. People who have strong views on issues of Church History or Book of Mormon geography often consider these views as part of their self-image and therefore become defensive when others disagree with their views.
Recognizing this would go a long way to resolving the problem.
Here are excerpts from Epstein's piece:
There’s Too Much Virtue in Politics
Our self-image is now so bound up in ideology that any disagreement feels like a personal attack.
We all disagree with others about various issues. Usually people can't even agree on the relevant facts because we all engage in confirmation bias. We filter out information that doesn't confirm our biases. We actually perceive the world differently because our of these psychological filters.
When it comes to matters of Church history and the Book of Mormon, everyone is on the same "team" in the sense of being a faithful member of the Church who wants to do good, live the Gospel, and share our faith in Christ.
But that doesn't make us immune from conflating our self image with our ideas.
In my view, one of the most important roles of a prophet is to break through confirmation bias. That's why, for me, it is foolish to repudiate what the prophets have taught, including what they've taught about the hill Cumorah in New York.
The sooner we reach consensus that the prophets teach the truth, the sooner we'll reach consensus about the New York Cumorah. And from there, the rest is easy.