A tendency to reinforce our devotion when asked to defend or explain our position. If we are asked to explain our feelings on an issue, as soon as the words leave our mouths we have already started to cement a position on the issue. Even if we have little or no background knowledge on it. We have the ability to convert hearsay, our own sense of logic or abstract thoughts into "facts" that we can draw upon to justify or explain our position. When challenged on the same idea in the future we are likely to take the original stance rather than revise it. Especially if we believe we hold the popular viewpoint.
"Jeremy Irons once said in an interview that if gay marriage were made legal, it would open up the ability for men to marry their sons. He was slammed by the media. In a media statement to follow he clarified his position by explaining that incest laws were there to prevent inbreeding and logically it does not prevent man and son from marrying."
Clearly his statement was narrow minded, but rather than say "hey I was suffering from verbal diarrhea that day" he became decidedly more resolute in his argument. He conbogulated his argument.