Forthcoming in the journal Sociological Forum, the study maps a general decline in advocacy for school prayer starting in the mid-1970s and accelerating as skeptical Baby Boomers became ascendant through the 1980s. According to the study's findings, school-prayer support remains markedly lower today among Catholics and mainline Protestants yet unwaveringly high among their evangelical counterparts.

University of Nebraska-Lincoln sociologist Philip Schwadel modeled data from the General Social Survey from 1974-2010 and created a measure for Americans' support for prayer and reading of religious scripture in public schools over the decades. The results tracked the impact of religious affiliation and generational differences on the role of religion in public education, he said.

"Social and cultural changes have led to greater opposition to state-sanctioned prayer and reading religious materials in public schools among some segments of the population," Schwadel said. "Specifically, there's growing opposition among non-evangelicals but not evangelicals, and these changes manifest across generations."

While these generational shifts have spurred changes among some denominations, evangelical Protestants have remained staunchly pro-school-prayer over the years, Schwadel said. As other religious denominations faced generationally influenced fluctuations on the topic, evangelicals persisted -- more than 70 percent of evangelicals expressed support for school prayer, regardless of what generation they came from.