MITT ROMNEY’S 2010 tax return, along with an estimated version of his 2011 filing, was released on Tuesday and attracted attention for a number of reasons — chief among them his high income and low tax rate. But the disclosure also called attention to his high level of charitable giving — much in the form of donations to the Church of Jesus Christ of Latter-day Saints — in a nation where most donate far less.

Mr. Romney, like other observant Mormons, tithes — that is, each year he gives 10 percent of his income to his church (the percentage is not exact; he appears to tithe based on his estimated income and then to make up for any gap the next year). Tithing is an ancient practice with roots in the Hebrew Bible but is rarely observed now. Mormons are an exception, because their church strongly emphasizes tithing, and considers it among the requirements for entering temples, where the church’s highest sacraments, including marriage, are observed.

Among non-Mormon people of faith in the United States, evangelical Protestants and Pentecostals tend to give the highest percentage of their income to charity, Catholics close to the lowest. “Nonreligious Americans are generally the least generous,” said Christian Smith, a professor of sociology at the University of Notre Dame. “Any religion makes you more likely to engage in voluntary financial giving.” President Obama, a Protestant whose most recent church membership was a mainline congregation, Trinity United Church of Christ in Chicago, gave relatively little to charity a decade ago, but steadily increased his giving as he became more prominent and donated 14 percent of his income in 2010; Newt Gingrich, a onetime Southern Baptist who converted to Catholicism in 2009, gave 2.6 percent of his 2010 income to charity.

Below, a politically timely look at giving to American churches and charities.