A Stanford study begun in the late 1960s shows a strong correlation between adult success and a childhood ability to defer instant gratification in favor of larger eventual rewards. Read on to find out how to stop your inner four year-old from ruining your life as an investor.

Great selection, low prices, and tolerable shopping conditions have long been recognized as Wal-Mart's winning formula. Fortunately, the company itself is starting to see it that way too. It hasn't been easy to attain, but Wal-Mart's self-knowledge should be good news for investors.