WASHINGTON — New research shows that when people are asked to rate their own faith group compared with others, they rate it more positively.

A survey by the Pew Research Center asked respondents to identify their feelings about various faith groups on a “cool” to “hot,” 1 to 100 feelings thermometer. A 50 was described as neutral, not having “particularly” positive or negative feelings.

Every group, from atheists to Catholics and black Protestants to white evangelicals, felt most warmly about people like themselves.

For example, Catholics get an 80 thermometer reading from other Catholics, compared with a 58 among non-Catholics, and evangelicals get a 79 from people who call themselves born-again or evangelical, compared with a 52 from non-evangelicals.

Rating one another sounds like a harsh high school popularity game, but the survey does show the clear correlation between knowing someone of another faith and feeling more positively about them.

For example, Jews get a 69 reading from people who know Jews, compared with a 55 from people who say they don’t know anyone Jewish. Atheists receive a neutral score of 50 among people who know an atheist, compared with a cold 29 by people who say they don’t know any atheists. People who know a Muslim give a neutral number (49) compared with a cooler one (35) from people who know none.

Scott Thumma, a sociology professor at the non-denominational Hartford Seminary, said such research is important to track social change. Hartford, which focuses on interfaith education, has run a research project called Faith Communities Today, which in 2000 found that only 7 percent of U.S. congregations reported worshipping with congregations from another faith. By 2010, that percentage had doubled. And the percentage of congregations doing interfaith community service jumped from 8 percent to 20 percent in that period.

Thumma said deeper research shows that Americans speak and think differently about other faith groups when asked in the abstract than they do when they are asked about specific interactions with people they know.