"The constant desire to always be fiddling with a portfolio ... over time, it tends to come at the cost of returns."

That's what Motley Fool columnist Morgan Housel tells host Matt Trogdon in the latest episode of Out On a Limb. It's a theme Housel covered extensively in his recent column, "Leave It Alone."

Housel noted that over time, a portfolio holding the original S&P 500 stocks would have beaten the actual S&P 500, which adds new stocks when companies get bought out or go out of business. It's an interesting lesson for individual investors, he suggests. While investors often feel the need to "do something" with their portfolio, sometimes the best advice is to just leave it alone.

Watch the video below for more of Housel's insights on how to control your emotions while investing.