Four years after the 2008 global financial crisis, the onset of a severe economic recession, and ongoing market turbulence, a lack of faith in equity investing appears to be lingering, even for long-term investors who say thatsaving for retirementis their top financial priority.

In an online survey of 850 adults inthe United Statesaged 21-50 with at least one investment account, just over six in 10 investors (61 percent) believe that investing in stocks is very important or important to helping them achieve their retirement savings goals. The survey was conducted inAugust by Harris Interactive forT. Rowe Price, of Baltimore.

And while about half of investors (51 percent) surveyed say that they have roughly the same tolerance for risk that they had before the financial crisis, 37 percent say they are now refraining from investing in stocks because of current economic or market conditions. Investors' reluctance to invest in stocks is reflected in data from the Investment Company Institute, which shows that net new cash flow into stock mutual funds was negative in 30 of the last 48 months—including 15 of the last 16—throughSeptember 2012.

Stuart Ritter, senior financial planner withT. Rowe Price, says, "The lack of faith in equities, even among long-term investors, is troubling. Historically,stocks have providedmore long-term growth opportunities than bonds, short-term investments, or other vehicles that are generally considered to be more conservative."

Investors' aversion to stocks stands despite historic evidence showing that stocks, as measured by the S&P 500 Index, have outperformed other asset classes with an annualized total return of approximately 9.8 percent between 1926 and 2011. The annualized returns for bonds and Treasury bills over the same period were 5.8 percent and 3.7 percent, respectively. Past performance isn't a guarantee of future results, and it isn't possible to invest directly in an index.

Over the course of a long-term retirement savings program, an under-allocation to stocks could lead to shortfalls in investors' account balances,T. Rowe Pricefinancial planners say.

"People withdecades to gobefore retirement need to do their best toblock out the noiseof the day and focus on the long term," Ritter says. "For investors with a long time horizon and enough tolerance for volatility, stocks have always been the best asset class for growth potential and for staying ahead of inflation."

For the 37 percent of investors who say they are currently refraining from stock investing, factors cited include the pace of the U.S. recovery, general market volatility, political uncertainty, rising health care costs, actual or potential unemployment, the pace of the global economic recovery, the pace of the U.S. housing market's recovery, the Eurozone debt crisis, and potentially higher taxes on income, dividends, and capital gains.

Risk aversion is also prevalent in investors' attitudes toward fixed-income investing, with 76 percent of investors saying they are only somewhat or not at all willing to take on more risk to obtain a potentially higher yield.

The crisis appears to have ushered in a new era of financial prudence: With respect to their personal savings, 81 percent of investors say they are saving about the same or more than they were before 2008.