The desire to remain consistent with one's previously established positions is one of the great psychological motivators:

https://www.amazon.com/Influence-Psychology-Persuasion-Busin...

People will often act against their own best interests to do so.

If you want to go more of the Psychology route:

Predictably Irrational (Dan Ariely, he has some TED talks as well) http://www.amazon.com/Predictably-Irrational-Revised-Expande...

Influence, the Science of Persuasion (Robert Cialdini) http://www.amazon.com/Influence-ebook/dp/B002BD2UUC