Less than half -- 45% -- of Generation X and Y investors plan to contribute to Individual Retirement Account accounts for the 2011 tax year, according to survey results from T. Rowe Price.

Most -- 55% -- said they do not plan to fund their IRA, or are unsure whether they will do so, this tax filing season. This is down from the 71% who did in 2010.

The survey was conducted between Dec. 1 to 12 last year by Harris Interactive among a national sample of 860 adults, aged 21-to-50, who currently have one or more investment accounts. Generation X investors are defined as ages 35-to-50 while Generation Y are defined as 21-to-34.

The survey attributed this investment weariness to:

• A belief that current participation in a 401(k) plan is adequate for now (42%)

• A feeling that they can’t afford it (32%)

• Economic uncertainty (23%)

• Market volatility (14%)

• Job uncertainty (12%)

The investors polled were also asked what they would do with an extra $5,000. Most of the respondents, or 56%, said they would pay off existing debt or add to a “rainy day” fund. Only 16% said they would contribute to an IRA.

"Given their economic fears, it is understandable why many younger investors might be unable or unwilling to fund all of their tax-advantaged accounts and are focusing primarily on their 401(k) during this tax season," said Stuart L. Ritter, CFP, senior financial planner for T. Rowe Price.

The study also indicates that many of these investors may have lost faith in stocks. In the survey, only 22% of Generation X and Generation Y investors feel confident about the financial markets heading into 2012. And among investors who plan to fund an IRA this tax season, 28% said they will direct their contributions to relatively stable investments such as money market funds.

Tommy Fernandez writes for Money Management Executive.