5 mental hang-ups that keep people from building wealth

• "Dollars and Sense," by behavioral economist Dan Ariely and Jeff Kreisler explains that people tend to approach money irrationally.
• But to build wealth, we have to out-think our emotions.
• To do it, we have to be aware of psychological pitfalls like "opportunity costs" and the "endowment effect."

Saving money is notoriously harder than it seems. Things pop up - car repairs, wedding gifts, invitations to concerts - and suddenly our good intentions go straight out the window.

So if you're trying to save more and spend less, you'd do well to stop telling yourself how important it is for your future well-being. Instead, you've got to trick yourself.

"Dollars and Sense: How We Misthink Money and How to Spend Smarter" is a new book by Duke University behavioral economist Dan Ariely and lawyer-turned-comedian Jeff Kreisler. The authors outline several ways in which people tend to approach their finances irrationally, and offer a series of creative strategies for becoming better money managers.

Below, Business Insider has rounded up five of the simplest and most compelling insights from the book.