Compared to Western Europeans and the Japanese, Americans are most willing to fight for their country, most proud of their national identity, most likely to take pride in their work, exceedingly religious and second only to the Irish in seeing themselves as most happy.

Those are some of the findings reported yesterday by an international team of social scientists engaged in an unprecedented international study of the fundamental attitudes that determine human behavior.

"We know how people vote, we know how people spend money, but never before have we examined how people reach basic decisions," explained the Rev. Cassian J. Yuhaus, president of CARA, the independent Roman Catholic-founded research center here that handled the U.S. portion of the survey. The study is being coordinated worldwide by the Gallup organization.

Among the findings:

Black Americans ranked highest in rating "the importance of God in life" at 9.04 on a scale of 10. Hispanics were next at 8.92 percent; white South Africans, 8.55; the United States as whole, 8.21. Swedes rated the importance of God at 3.99 percent, higher only than the Danes and Japanese.

Four out of every five Americans said they were very proud to be a citizen of their country; 66 percent of the Irish and 55 percent of the British polled responded affirmatively to the same question. At the bottom of the scale, only 30 percent of Japanese and 21 percent of West Germans said they were "very proud."

In case of war, 71 percent of the Americans said they would fight for their country, followed by Britain with 62 percent. Only 22 percent of Japanese answered that question affirmatively, with 38 percent undecided. Italy had the highest percentage -- 57 percent -- who said they would not fight.

Questions on work drew responses that CARA research director Edward Sullivan called "one of the surprises of the study." In a ranking of job characteristics, "good pay" and "pleasant people to work with" ranked at the head of most lists. Japanese, however, gave first priority to "a job that meets one's abilities," which Americans, Irish and French ranked sixth.

On the question of pride in one's work, 84 percent of Americans said they take "a great deal of pride," but only 37 percent of Japanese, 15 percent of West Germans and 13 percent of the French reflected that attitude toward their work. Four out of 10 West Germans said they take little or no pride in their work.

Continuing interviews will study values in a total of 26 countries, including Hungary, Australia, and some Latin American nations. The fullest data released yesterday covered Great Britain, Ireland, Japan, West Germany, France, Italy and Spain, as well as the United States. Responses from Denmark, Sweden, Belgium, Holland and South Africa were included in some of the items.

The findings came from hour-long interviews with a scientifically selected sample of from 1,200 to 2,000 persons in each of the countries studied. In this country, additional sampling was done among two major ethnic minorities, blacks and Hispanics.

Yuhaus said that one of the reasons for the study has been "a conviction of a major shift in values in various parts of the world. If that is occurring, it will have a major impact on social policies" and will affect governments and businesses as well as educational, religious and other institutions.

On religion, 81 percent of Americans said they considered themselves religious, whether or not they go to church. Only the Italians, with 83 percent, had a higher rating. Ninety-five percent of Americans believe in God, (2 percent are avowed atheists and 3 percent do not know); 71 percent believe in life after death; 84 percent believe in heaven, and 67 percent believe in hell.

In a question on the Ten Commandments, 93 percent of Americans agreed that "Thou shalt not kill" and "Thou shalt not steal" still apply fully today. The commandment to keep the sabbath holy was least popular among Americans, with 57 percent assenting, while 87 percent believed the commandment against adultery still applies.

More West Germans--61 percent -- than Americans--51 percent -- agreed with the thesis that "sexual activity cannot entirely be left to individual choice -- there have to be moral rules to which everyone adheres." The British and French, each with 42 percent, expressed the most disagreement with that statement.

Financing of the venture, which Gallup's London director, Gordon Heald, called "one of the largest single social science studies ever done," has come from a wide range of sources that Heald said range from a Swedish insurance company that gives discounts to drivers who do not drink, to the Japanese Leisure Development Center.