NEW YORK  Non-Orthodox Jewish men are becoming alienated from their faith, a "crisis" that foreshadows a rise in interfaith marriages and secular generations, according to a new study from Brandeis University.

The findings, based on 300 interviews, report the rise of female leadership and participation in Reform, Reconstructionist and Conservative Judaism has prompted men to opt out of religious activities, in contrast to Orthodox Judaism, which still requires men for traditional worship and family life.

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"The past four decades have contradicted thousands of years where men were the primary (leaders) in terms of religious roles," said Lindsey Fieldman, spokeswoman for the Hadassah-Brandeis Institute, which released the study this week.

With women currently outnumbering men in weekly non-Orthodox worship services, adult education classes, volunteer leadership positions and cultural events, the study concludes that non-Orthodox groups should create programs aimed specifically at engaging boys. The earlier the better, the study reports, because alienated Jewish men are more likely to marry non-Jewish women, taking them and their children farther away from the synagogue.

"The Jewish community must intervene well before the marriage years if it hopes to have an impact," the study reports. "Not only does the presence of a Jewish mother in the home dramatically increases the likelihood that the children will be raised as Jews, her absence increases the likelihood that they will not."

The Reform movement has struggled with its growing gender gap for years, stunned by a two-to-one ratio of women to men entering the rabbinical class in its Hebrew Union College in 2005. Last year, the movement launched a three-year campaign to address the problem, called "Where Have all the Young Men Gone?"

Some of the imbalance can be blamed on American culture, which places higher values on women's participation in religious and educational activities, and has caused similar struggles in churches across the country, said Jonathan Sarna, American Jewish history professor at Brandeis University.

"I don't think we need a fancy Jewish explanation for what's going on," he said. "Non-Orthodox Judaism is becoming more like American religion as a whole, which has been largely female."

As a result, Sarna believes, Americans will begin seeing a marked increase in all-male activities sponsored by churches and synagogues, pausing or reversing efforts to raise the status of women in congregations.

"We're going to see stronger efforts to bring back groups for men — clubs for men, services for men, sports teams and so on," he said. "It may not be fair ... but that's the way it is."