"Nothing in life is quite as important as you think it is while you are thinking about it."
-- Daniel Kahneman and David Schkade

Would you be happier if you lived in California?

Chances are that if you don't currently live in California, your answer would be "yes." Or, at least, that's what a 1998 study of roughly 2,000 students by researchers Kahneman and Schkade showed.

In the study, students who lived in the Midwest believed that similar students in California were happier than they were, while the Californians also assumed that they were happier than their Midwest counterparts. Based on the data, the researchers concluded that both groups focused specifically on the climate differences -- certainly people dealing with bitter Midwestern winters couldn't be as happy as Californians soaking up the warm sunrays on the beach. Could they?

But here's the rub: There was no difference between the actual self-reported happiness of both groups. To be sure, the Midwesterners weren't thrilled about the weather in their region, but it didn't hold them back from being just as happy overall as the Californians.

If I were a rich man
In a more recent study by Kahneman, Schkade, and other academics, there was a similar finding after digging into people's expectations about how a higher income would impact happiness. That is, participants assumed that more money would make a much bigger difference on their happiness than was reasonable to assume.

Now you could stop reading right here and have a perfectly good takeaway. We all need to be aware of this "focusing illusion," which causes us to make broad global assumptions about our well-being based on the most obvious aspects of an issue. We figure, for instance, that a higher income will make us happier because we focus on all of the ways money would make our life easier, while ignoring the potential for grueling work hours, a more demanding boss, or a longer commute.

But you came here for investing
As investors, we need to be just as careful about focusing too much on one aspect of a stock. In a world of fast-cut TV, sound bites, and Tweets, it's easy to jump on one obvious, glaring aspect of a company and assume that it paints an accurate picture of the entire company or the stock.

Getting specific, here are a few companies where it's easy to tune into one very obvious feature of the company.

  • Berkshire Hathaway (NYSE: BRK-B). Is Warren Buffett a big deal? You bet your sweet backside he is. And without Buffett, the name Berkshire Hathaway would likely be buried in the annals of history as just another U.S. textile operation that faded to black. But the Berkshire of today is a massive conglomerate that wholly owns many companies that are run by many savvy operators. It also has a huge stock portfolio with multibillion-dollar positions in companies like Procter & Gamble (NYSE: PG) and Wells Fargo (NYSE: WFC). In other words, Berkshire is much more than its CEO.
  • Sirius XM Radio (Nasdaq: SIRI) and Chipotle Mexican Grill (NYSE: CMG). Peter Lynch is famous (infamous?) for advising that you should "buy what you know." While this can be a great starting point for an investment, just because you like Sirius' service or Chipotle's burritos doesn't necessarily mean that you're looking at a good investment opportunity. Is the product nicely profitable? Does the company have a sound balance sheet? Is the stock's valuation reasonable? These are just a few questions you need to explore even if you think the product is the greatest thing since sliced bread.
  • Annaly Capital (NYSE: NLY) and Chimera Investment (NYSE: CIM). You don't need to tell me that dividends are back in vogue -- I'm well aware. But investors focusing solely on grabbing the fattest yields out there may be ignoring the bigger picture at the companies they're investing in. When it comes to mortgage REITs like Annaly and Chimera in particular, my fellow Fool Alex Dumortier noted this week that the group could run into trouble because of the way they finance themselves. And, as Alex put it, "the dividends aren't free money."

Keep digging
There's nothing wrong with being drawn to a company because of some big headline issue -- a great CEO, an innovative product, a hotshot institutional investor that's taken an interest. But be careful about letting that act as a halo over the entire company and assuming that one feature makes it a great investment for you. Instead, do your homework, explore further, and get to know the entire company.

My fellow Fools may have been drawn to this group of 13 stocks because of their dividend yields, but they think these stocks are the real deal. Check out the special report "13 High-Yielding Stocks to Buy Today" free by clicking here.

And next time you're sitting around thinking that the grass may be greener elsewhere, just remember, California is a great place, but it also has high taxes, soul-sucking traffic, and -- in the most desirable areas -- a cost of living that can make even the wealthy feel like they're scraping by.