You’re trying to save more money, but can’t find the spare change, or maybe you’re trying to stop snacking at 4pm, but reach for the cookie like clockwork. The latter was exactly what was happening to Charles Duhigg, and he was so eager to break his own bad habits, he went on to become an expert in changing our behavior with his bestsellers, “The Power of Habit” and “Smarter Faster Better.” We explore the psychology behind habit formation and discuss solutions for long-term behavior modifications. In Mailbag, we go over how to choose a Roth IRA, a financial planner and how to start investing with your kids.