Title look familiar? Thought it might. Back in June, Amy Sutherland wrote an essay for The New York Times called "What Shamu Taught Me About a Happy Marriage" (registration required) that became so popular and buzzed about that the online magazine Slate wrote a snarky article aboutthe article.

File under: heavy meta
If you haven't seen it yet, the gist of it is that if you want a happy, healthy relationship, follow the example of animal trainers. Offer positive reinforcement for your partner's good behavior (though preferably not in the form of raw, live fish) and react to his or her, um, less desirable traits not with hostility but with indifference, on the theory that even a negative reaction can reinforce the bad behavior.

When Sutherland used these techniques on her husband, they worked wonders. The results were so impressive, she writes, that "I felt as if I should throw him a mackerel."

Which got me thinking about investing
No, really. Do Shamu and his trainers have something to teach us when it comes to putting our money to work? I think the answer is yes, at least in part.

As the Fool's resident fund geek, one of the main things I look for is a money manager who sticks to his strategy even during lean times. If, for example, a manager who has established a superior long-term track record by focusing on value-priced large-caps such as Pfizer (NYSE:PFE), Citigroup (NYSE:C), and Valero Energy (NYSE:VLO) hits a rough patch, my inclination is to see it as good news: Unlike Shamu, the market is a fickle beast, and when a manager's battle-tested strategy falls from favor, that gives him a chance to snap up shares of the kinds of companies he likes at an even steeper discount.

It also gives savvy investors an opportunity to provide positive reinforcement by continuing to invest in the fund, perhaps even dialing up their stake. Doing so, after all, can help them reap the rewards of putting the old "buy low, sell high" saw into action.

If, however, that same manager suddenly throws his strategy to the wind and starts chasing smaller-cap stocks such as SiRF Technology (NASDAQ:SIRF) and CNET Networks (NASDAQ:CNET) or racy big boys like Yahoo! (NASDAQ:YHOO) and Broadcom (NASDAQ:BRCM) simply because he thinks they look "hot," well, that's a strong indication that it's time to reel in your line, so to speak, and start fishing in other waters.

The Foolish bottom line
Which is where I part ways with the animal trainers. When it comes to money managers or the honchos behind the individual companies you own, that kind of finger-in-the-wind behavior shouldn't be met with indifference.

Heading for the exits is more like it and, as it happens, in the next issue of our new personal finance newsletter, GreenLight, we'll serve up a primer on when to sell. For lots of investors, that side of the transaction is far trickier than buying, so we'll key in on three criteria that can help you simplify your approach to selling and get the job done with a minimum of muss and fuss.

If that kind of basic financial training sounds like it might be useful, click here to snag a free 30-day guest pass and give GreenLight a go. In addition to the newsletter, your pass provides access to our members-only website and discussion boards, too. There's no obligation to stick around if you find the service isn't right for you, so go ahead and (bad pun alert!) dive on in.

Shannon Zimmerman runs point on the Fool's Champion Funds newsletter service and co-advises GreenLight with his pal Dayana Yochim. At the time of publication, Shannon didn't own any of the securities mentioned above. Yahoo! is a Stock Advisor recommendation; Pfizer is an Inside Value pick; and CNET is a Rule Breakers selection. You can check out the Fool's strict disclosure policy by clicking here.