Americans think so highly of Social Security that 77 percent would voluntarily join it and subject themselves to the tax if they had the option of going in or staying out.

Moreover, they don't mind the tax as much as a lot of members of Congress may think. They resent it less than other forms of federal and state taxation.

They would rather pay bigger Social Security taxes than cut future benefits. And if money is needed, they would rather get it from increasing the Social Security taxes than from imposing a new value-added tax (national sales tax) or taking it from income tax revenues.

However, they are worried about talk of future financial problems for the system. Over half fear the money won't be there when they retire.

These are the key findings of a nationwide survey of 1,549 persons of all ages and racial and economic groups released yesterday by the National Commission on Social Security, a study group set up by Congress. The survey, by Peter D. Hart Research Associates, was conducted in respondents' homes Nov. 16-29, 1979.

The findings appear to knock down some popular Capitol Hill notions about Social Security -- namely, that people bitterly resent the tax increases needed to maintain it, increasingly dislike the system and resent having to take part.

Those beliefs have led to congressional demands over the past two years for a rollback of payroll tax increases scheduled to take place next Jan. 1, perhaps to be replaced by a value-added tax or general revenue financing.

The new survey indicates that many of these propositions simply aren't true.

For example, the survey found that 77 percent of the population would choose to participate in the Social Security system if given the option of staying in or out during their working lives. And 76 percent would object to its abolition now -- nearly all very strongly.

The survey showed that 60 percent felt payroll taxes are about right or even a bit low, while only a quarter felt they are too high. And while three persons in 10 object to paying Social Security taxes, half strongly, the other half mildly, the figures are much higher for other types of taxes, some 59 percent object to the gasoline tax, 41 percent the income tax and 38 percent the state sales tax.

Given the choice between boosting Social Security taxes and reducing benefits, now or in the future, 63 percent favored higher taxes and only 15 percent favored reducing benefits.

And while respondents favored by a narrow margin using general revenues to pay for Medicare, they opposed using either income tax money or a sales tax to pay for other benefit increases.

Asked whether they preferred payroll tax increases or income tax increases to fund benefit increases, 49 percent favored increasing Social Security payroll taxes and only 26 percent raising income taxes, with the rest undecided. In a choice between payroll tax increases and imposition of a value -- added tax, payroll taxes were the choice, 45 percent to 31 percent.

All these results show pretty solit support for the system, but in one area, the results were gloomy: 42 percent of the 1,549 interviewees were strongly confident that the system would have the money to pay benefits when they reached retirement age. Another 52 percent had little or no confidence, a result spurred, commission members said, by tumult over refinancing legislation in the past few years.

Hart said he was amazed at how sophisticated people are about Social Security: a majority know that benefits are wage-related, that an individual's contributions go into a general benefit fund, not into individual accounts, that the system works on a pay-as-you-go basis, that it isn't intended to provide the sole source of retirement income, that Medicare, disability and survivor benefits are part of the Social Security system.