This is a guest post from Robert Brokamp of The Motley Fool. Robert is a Certified Financial Planner and the adviser for The Motley Fool’s Rule Your Retirement service. He also has a blog, Twittering thing, and a piece of carpet that was once in Elvis’ jungle room (no joke!). Robert contributes one new article to Get Rich Slowly every two weeks.

When I’m not reading about personal finances or World War II, I’m often reading some sort of psychology-related book or article in an attempt to answer the age-old question, “Why do we do sub-optimal things when we know better?”

Of course, that question can be applied to personal finances and world wars. For years, people have asked themselves such questions as “Why did I spend my money on something that provides no lasting value?” Or “Why did I watch ‘American Idol’ rather than open an IRA?” Or “Why did I take orders from a guy with a bad mustache and gas problems?”

My latest attempt to solve this conundrum (the one about making less-good decisions, not the one about following smelly people into moral depravity) began with reading an article by Sebastian Marshall on Lifehacker, which listed seven cognitive costs of doing things. Among them is “ego/willpower depletion.” It’s a concept I’ve heard of before, but hadn’t delved into.

Ego Depletion
The term “ego depletion” was coined by Florida State psychology professor Roy Baumeister, and is used to describe the theory that (in the words of Wikipedia) “self-control or willpower is an exhaustible resource that can be used up. When that energy is low, mental activity that requires self-control is impaired. In other words, using one’s self-control impairs the ability to control one’s self later on.”

Not only is willpower impaired, but so is the ability to solve problems or stick with a project. This can be illustrated in a series of experiments [PDF] performed by Baumeister along with colleagues Ellen Bratslavsky, Mark Mruaven, and Dianne M. Tice.

Cookies or radishes?
In one experiment, subjects were led into a room that had both cookies (baked in the room for full aromatic effect) and radishes. One group was allowed to eat the cookies, another was told they could only eat the radishes, though they were left alone in the room and could have sneaked a cookie if they wanted (but they didn’t). Then, the subjects were given a geometry puzzle that (unbeknownst to them) was unsolvable.

The results: Subjects who were allowed to eat cookies spent twice as much time on the puzzle before giving up as did the subjects who were relegated to the radishes. Resisting the urge to stick cookies in their mouths had depleted their stick-to-itiveness.

Free Macro Chewy Cocolate Chip Cookies Creative Commons   back in season ....
Cookies or radishes: Would you have the willpower to resist?

Funny or sad?
In another experiment, subjects were shown “emotionally evocative” videos. (For the kids in the audience, “videos” were black plastic rectangles that contained magnetic tape on which movies were recorded; the ones found hidden deep in your father’s closet were definitely “evocative,” though not the kind used in these experiments.)

Two groups were shown funny or sad videos. One group of participants was encouraged to “let their emotions flow while watching the movie” (even, presumably, if they wanted to laugh during the sad scenes), and one group was “instructed to try not to show and not to feel any emotions during the movie”; they were told they would be videotaped, “so it was essential to try to conceal and suppress any emotional reaction.” (The other group was also videotaped.)

After watching the video, the participants were asked to create as many anagrams as possible with 13 sets of letters within six minutes. The result: “Participants in the suppress-emotion condition performed significantly worse than participants in the no-regulation condition in terms of number of anagrams correctly solved.”

“Thank You, Sir, May I Not Have Another?”
While reading about ego depletion, the first real-world application that came to mind is my attempt to eat better and lose weight (which I wrote about last June, and it’s one of my favorite contributions to GRS, so, like, go read it if you haven’t already). I’m happy to report that I’ve lost 20 pounds over the past 11 months, and shorts that were a bit tight are now a bit baggy. But it hasn’t been easy, and I’ve noticed that it gets more difficult as the day goes on. I find it much easier to resist the donuts at work in the morning than I do the ice cream at home in the late-night hours.

I’ve also noticed that my cravings for all kinds of things spike near the monthly deadline for my newsletter. Of course, a smart person would spread the month’s work over the entire month. But, well, I can’t seem to do that, which leads to a “that time of the month” condition my wife calls PNS: Pre-newsletter syndrome. I work late hours, forgoing anything that doesn’t have to do with my newsletter — and I have much less success at resisting junky food and sporadic spending.

Is this a tradeoff I have to make? For most of the month, do I deplete my willpower resources resisting one set of suboptimal behaviors — such as eating junk, spending wildly, leaving the house partially clothed — which leaves little left to resist the temptations that prevent me from writing my newsletter until the last minute? Then, come the end of the month, all my willpower resources are consumed by getting my work done, and I spend all my time at my desk writing, spending too much on junky food, half-naked.

Or maybe that’s being just smart, since the studies referenced earlier found that performance suffered when restraint was exercised. Maybe my newsletter is better by my giving in. We can call this the “Debauch Yourself to Awesomeness” theory, as proposed by Dr. Frank-N-Furter with his/her exhortation to “give yourself over to absolute pleasure.” (Rocky Horror, anyone?) I might be willing to give it a try — just for scientific purposes, of course.

Lead Yourself Not Unto Temptation
I haven’t read enough about willpower/ego depletion to yet know the solution to the problem, but I’m willing to guess that it starts with limiting temptations and thus the need to exercise your restraint muscles. If diet is a problem, stay out of the kitchen and steer clear of those bowls of snacks in the office. If spending is a problem, stay away from stores and unsubscribe from retailers’ email lists, including Groupon, Living Social, and their ilk.

For me, time management is the biggest struggle; in fact, while writing this post, I found myself watching a YouTube video of a lacrosse game. How did that happen? It started with me looking for a video from The Rocky Horror Picture Show to include, deciding it was too weird, but then I was off to Distractionland, where every ride seems more fun than the one you’re waiting in line for.

Email’s a killer for me; I found I was compulsively checking it several times an hour, to no good end. The solution I’ve tried with some success: Close it and don’t reopen it for at least an hour (I even have a timer at my desk).

But I’m sure you have some tricks yourself. How do you resist temptation? How do you make sure you get the important things — financial or otherwise — done? Add your tips to the “comments” section below. I’ll be sure to read them, because — after making myself close email, leave YouTube, and finish this post — I have no more willpower to resist them.

Awesome cookie photo that is breaking down my willpower by Pink Sherbet Photography. Completely un-tempting radishes by the hills are alive.

This article is about Psychology