The latest in a flurry of studies on young American Jews suggests that Orthodoxy will become a larger and more influential force in coming decades. The study, which looked at the 1.5 million US Jews between the ages of 18-39, found that Orthodox Jews comprise some 11 percent of all US Jews, and 16 percent of 18-29 year-olds. Among even younger Jews, the percentage of Orthodox is even higher, those behind the report speculate. Further, the survey found, Orthodox Jews marry at a younger age, have more children and are more Jewishly engaged than their non-Orthodox counterparts. Released Thursday by the American Jewish Committee as part of its centennial celebration, the findings confirm both anecdotal and quantitative evidence from previous reports. Taken together, the authors say, the facts strongly indicate an ascendant Orthodoxy among US Jews. "Younger Orthodox adults are likely to play increasingly important roles in organized Jewish life given their commitments, numbers and fertility patterns," said Steven Bayme, director of contemporary Jewish life at the AJCommittee, which commissioned the study by Ukeles Associates. Looking at young American Jews and their connection to Judaism, the study - "Young Jewish Adults in the United States Today: Harbingers of the American Jewish Community of Tomorrow?" - found they can be broken down into four sub-categories: Orthodox; non-Orthodox inmarried couples with children; non-Orthodox Jewish singles and married couples without children; and intermarried couples, with and without children. The first two categories make up about 25 percent of Jews aged 18-39, the study found. They are the most engaged with Judaism, the Jewish community and Israel. The remaining three-fourths of young Jews are "much less engaged." The study is based on current knowledge of Jews in the 18-39 age bracket. It analyzes data from a series of Jewish community studies by Ukeles Associates; the National Jewish Population Survey of 2000-01; and AJCommittee's national surveys of American Jewish opinion since 2000. It's one of several studies of young Jews to come out in recent months, including surveys by Brandeis University; Reboot, a nonprofit group that promotes creative Jewish initiatives; sociologist Steven M. Cohen of Hebrew Union College-New York; and Hillel: The Foundation for Jewish Campus Life. "The future Jewish community is going to be shaped by paths not yet taken," said Jack Ukeles, president of Ukeles Associates. "While we don't have a crystal ball, we do have a pretty good sense of how these behaviors are going to change the community." The report found that the percentage of Orthodox Jews aged 18-29 is nearly double the percentage in the 30-39 age group. Considering that a higher percentage of Orthodox Jews marry, do so earlier and tend to have more children than other groups, this could indicate a growing role for Orthodoxy down the line. More than half of all American Jews under the age of 40 are not married, the study found. That figure goes up if Orthodox Jews, who are more likely to be married by age 30, are excluded. "The implications of this are staggering when one considers how much of the Jewish community's resources are dedicated to the family," Ukeles said. Other notable findings include: â€¢ The Holocaust is proving more important than Israel in positively affecting Jewish identity among many young Jews. "The Holocaust continues to be profoundly important to a broad spectrum of young Jews, yet Israel appears to be much less important in positively affecting Jewish identity," the study said. However, among those who have traveled to Israel and among the Orthodox, Israel retains a powerful positive resonance, the report found. â€¢ Warnings that young Jews are deserting in droves and that the community faces extinction are overblown. While young Jews are not joining conventional Jewish institutions and organizations as their predecessors did, they still are connecting with Judaism - but more personally, informally and episodically. Identification is "built around common interests and experiences," not organizations, Ukeles said. The study raised questions about what impact the growing power of the Orthodox community would have. "As Jewish organizational planners think in terms of the community of the future, the more they try to appeal to that group that is most interested, it may find itself losing an even larger group that doesn't want that kind of intensity," Bayme said. On the other hand, if organizations cater to the larger but less engaged group, they risk alienating the most committed Jews. "Understanding the Jewish community of tomorrow is imperative if present-day Jewish organizations are to remain relevant," said Amb. Alfred Moses, chair of the AJCommittee's centennial committee.