In "Understanding the ‘Want’ vs. ‘Should’ Decision," Todd Rogers and Katy Milkman make this interesting comment about how should and want related to our long-term and short-term interests:

People often behave as if they possess multiple selves with different, competing interests. We call 2 of these metaphorical selves the "want-self" and the "should-self."

The want-self is myopic and desires instant gratification. If left to its own devices, the want-self would always act on immediate, visceral desires (e.g., spending instead of saving money, eating junk food instead of health food). The should-self, on the other hand, prefers to behave in a way that will maximize long-run benefits. If left to its own devices, the should-self would always act on behalf of an individual’s long-term best interests (e.g., saving money or donating it to a good cause instead of spending frivolously, eating health food instead of junk food).

The "multiple selves" metaphor resonates with many people because most of us regularly struggle with choices between 2 options, one of which we know we should choose because it would be virtuous to do so and one of which we want to choose to satisfy our visceral desires. An obvious example of this type of dilemma is the choice of what to eat for lunch: a slice of pizza or a salad? What do you think you should eat? Now, what do you feel, viscerally, that you want to eat? For most people, this is an easy one: They want to eat the delicious, greasy pizza but know they should eat the healthy salad. This is a classic example of want-should conflict.

Past decision-making research has shown that when a decision will take effect in the future, people weigh the interests of the want-self less relative to the interests of the should-self. For instance, you are more likely to agree to put additional money in your savings account if that money will be withdrawn from a future paycheck rather than the paycheck in your pocket (Benartzi and Thaler, 2003). Similarly, you are more likely to donate money to a good cause if the donation will come out of a future paycheck (Breman, 2007).

Although Rogers and Milkman are writing for a business environment, their comments have a spiritual application as well. Christians must learn to restrain our "wants" by practicing the virtue of patience, so that we spend our time, talent, and treasure on our "shoulds." Even better, we should strive to develop holy "wants" that are more closely aligned with godly "shoulds," so that our short-term and long-term behaviors match. Indeed, this is my only critique of Rogers and Milkman: they don’t envision the possibility of developing positive, virtuous "wants." But as a pastor, I believe this is both possible and desirable.