As defined benefit pension plans continue to be phased out, the responsibility to both save and invest for retirement has shifted to the individual. And, at least so far, we don't seem to be shouldering the burden with a great deal of success.

The statistics paint a bleak picture. A recent survey commissioned by the Federal Reserve found that 31% of respondents have no retirement savings or pension, including 19% of those ages 55 to 64, and 25% didn't know how they will pay their expenses in retirement. The net result is that an uncomfortably large number of retirees rely on Social Security as their primary means of support even though the system was designed to be supplemental.

Beyond saving more during our working years, the most effective way to break this chain of unpreparedness is to invest -- and, it's important to add, to do so profitably. With this in mind, I've drawn up a list of five things that all investors should know to increase their chances of succeeding in the market.

1. We're programmed to fail
This may seem like a dispiriting way to begin a list about how to invest, but recognizing that the vast majority of us are biologically designed to fail is critical if we want to avoid doing so.

The problem is that we make investing decisions based on how we feel rather than on what we know, explains Carl Richards in The Behavior Gap: Simple Ways to Stop Doing Dumb Things With Money.

When we feel as if things are going great, we get greedy and pour money into the market. Then, when things take a turn for the worse, fear incites us to sell out. It's the classic case of buying high and selling low.

Here's how Richards sums it up with a Sharpie:

It's for this reason that Warren Buffett implores investors to be "greedy when others are fearful and fearful when others are greedy."

2. Few of us will beat the market
Given what you just read, you probably won't be surprised to learn that the majority of investors underperform the market -- that is, the S&P 500.

According to a study of investor returns conducted by Dalbar, a Boston-based analytics firm, the average equity fund investor has returned 5.02% a year since 1993. By contrast, the S&P 500 has returned an annual average of 9.22%.

As the study's author's note (emphasis added):

We have learned that the greatest losses occur after a market decline. Investors tend to sell after experiencing a paper loss and start investing only after the markets have recovered their value. The devastating result of this behavior is participation in the downside while being out of the market during the rise.

The flow of money into and out of the stock market confirms this point.

According to data collected by the Investment Company Institute, over the past decade and a half, money gushed into stocks at the height of the market in 2000, 2004-06, and 2013. Meanwhile, the flows reversed course after stock prices touched bottom in 2002 and 2008.

3. Trading stocks is a losing proposition
We should take it as a hint that one of the seminal papers in the field of behavioral finance is titled "Trading Is Hazardous to Your Wealth."

Beyond showing that trading stocks is a losing proposition, the authors demonstrate that it's also a matter of degree. In other words, the typical investor's returns decrease as his or her trading velocity increases.

As the authors explain:

Individual investors who hold common stocks directly pay a tremendous performance penalty for active trading. Of 66,465 households with accounts at a large discount broker during 1991 to 1996, those that trade most earn an annual return of 11.4%, while the market returns 17.9%.

One reason for this performance is our penchant for buying high and selling low. Another is that trading generates transaction costs in the form of commissions and taxes on realized gains.

Take this anecdote from Warren Buffett's 2005 letter to the shareholders of Berkshire Hathaway (emphasis added):

Long ago, Sir Isaac Newton gave us three laws of motion, which were the work of genius. But Sir Isaac's talents didn't extend to investing: He lost a bundle in the South Sea Bubble, explaining later, "I can calculate the movement of the stars, but not the madness of men." If he had not been traumatized by this loss, Sir Isaac might well have gone on to discover the Fourth Law of Motion: For investors as a whole, returns decrease as motion increases.

4. Beware of experts (and the financial media)
If you watch CNBC or Bloomberg, you've no doubt come across countless experts who offer predictions about which way the market is headed. Unfortunately, the reality is that nobody knows, and it's best to ignore anybody who claims to.

This is true of even the world's brightest minds and best-known prognosticators:

  • In 1929, Irving Fisher, by many accounts the "greatest economist the United States has ever produced," claimed that the stock market had reached a "permanently high plateau." This was promptly followed by the Crash of 1929.
  • In 1979, a BusinessWeek cover story titled "The Death of Equities" concluded that, "[f]or better or for worse, the U.S. economy probably has to regard the death of equities as a near-permanent condition -- reversible someday, but not soon." The stock market soon set off on a 20-year bull market that culminated in the S&P 500's 14-fold increase.
  • In the mid-1990s, best-selling author Harry Dent Jr. predicted that the Dow was headed to 40,000. Nearly two decades later, it's short of 17,000. And in the interim, it crashed twice. That hasn't stopped Dent. His latest book, published earlier this year, instructs readers how to "survive and prosper during the great deflation of 2014-2019."

The problem is that the mainstream financial media isn't designed to help you invest better. Its purpose is to entertain you. And oftentimes that's accomplished by making things seem simpler and more certain than they really are.

Financial commentator Josh Brown discusses this point in his latest book, Clash of the Financial Pundits:

Of all the verticals, financial media is the only one where there's supposed to be some sort of responsibility that comes along with it. Maybe politics a little. But when you think about fashion, art, sports, Hollywood gossip, in all of these different huge categories of news -- by the way, most of those dwarf financial news -- there is no responsibility. People don't watch ESPN and then think they're supposed to go out and play tackle football with 300-pound guys. But for some reason, when they watch financial or business news, they then take the next step in a lot of cases and say "I'm supposed to act on this now."

5. Time is your "last remaining edge on Wall Street"
After reading all of this, you'd be excused for throwing your hands in the air and concluding that investing in stocks, and not just trading them, is a fool's errand. But that would be a mistake.

The truth is that genuine investing is a lucrative and worthwhile activity. You just have to do it the right way by taking advantage of what my colleague Morgan Housel calls your "last remaining edge on Wall Street." What Morgan's referring to is time -- that is, your investment horizon.

As he explains:

The biggest risk investors face is losing money between now and whenever they'll need it (retirement, school, etc.). The good news for you -- and bad news for Wall Street -- is that the odds of losing money drops precipitously the longer you're invested for.

To illustrate this point, Morgan drew up the following chart, which is based on the S&P 500's performance from 1871 to 2012. Based on this analysis, the chance of losing money in the market drops to zero once your holding period reaches 20 years.

The reasons are twofold. In the first case, long holding periods smooth out short-term irrational fluctuations in the market. That allows stocks as a whole to mimic the irrepressible climb of U.S. gross domestic product. And in the second case, a longer holding period exposes your portfolio to the law of compounding returns.

It's for these reasons that Buffett wrote in his 1988 letter to shareholders that "when we own portions of outstanding businesses with outstanding managements, our favorite holding period is forever."

In conclusion, if there's nothing else you take from this list, let it be that. Buy-and-hold isn't dead. It's the strategy of the world's most successful investor. And there's no reason to believe that it won't work for you as well.

John Maxfield and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.