(Korona Lacasse/Flickr)
We tend to devalue happiness when making everyday decisions.

Nearly two decades ago, a professor at the University of Chicago conducted a somewhat amusing but telling study.

Experimenters asked about 150 university students to imagine that they had won a lottery drawing and could choose one of two chocolates as their prize.

Chocolate A, they were told, was an 0.5 oz. piece of Austrian milk chocolate worth 50 cents, shaped like a heart. Chocolate B, on the other hand, was a 2 oz. piece of Austrian milk chocolate worth $2, shaped … like a disgusting cockroach.

Experimenters asked the students: Which chocolate would they choose? And which would they feel better about eating?

As it turns out, a whopping 68% of the students opted to eat the roach. But just 46% predicted they would feel better eating it.

Raj Raghunathan, a professor at the University of Texas McCombs School of Business, cites this study in his new book, "If You're So Smart, Why Aren't You Happy?", as an example of a phenomenon he calls "mind addiction." It's the tendency to ignore or underestimate the importance of gut instincts and feelings, and it can make you a lot less happy.

Back to that chocolate study, which was conducted by Christopher Hsee. In that case, many students downplayed the disgust they would feel eating something that looked exactly like a bug, and chose the "rational" option of getting more bang for their buck.

Mind addiction, and our need to rationalize everything we do, affects our behavior in a lot of real-world situations, too. Let's say you're deciding between two job offers and you're leaning toward one because your prospective coworkers seem a lot nicer.

There's a chance you'd choose the job with less friendly coworkers, because it meets more of your criteria, like high pay and compensation.

Or you might choose the job with warmer coworkers, and tell yourself it's because there could be more opportunities for advancement there. You'd either be unaware that the coworkers' friendliness influenced your decision, or unwilling to admit it.

In both the chocolate experiment and the hypothetical job scenario, mind addiction leads to devaluing happiness.

However, Raghunathan points out that sometimes it's better to rely on thoughtful deliberations, as opposed to feelings. The key to making happiness-inducing decisions is self-awareness: knowing what kind of decision you're making and how the result will affect you.

For example, if you don't have much experience in a particular field, it would be wise to spend a lot of time thinking about your decision, instead of going with your gut.