Since the conception of a religious strength question in 1974, the General Social Survey (GSS) has never measured a lower amount of U.S. Catholics that are self-described as "strong" Catholics.  Pew reports that in 2012, the amount of Catholics claiming strong religious identity was 27%.  "Strong" Protestant religious identity has been rising in recent years and was found to be almost double the Catholic numbers with 54% of Protestants claiming strong religious identity in 2012.

In addition, the GSS reveals that both among Protestants and Catholics there are marked correlations between strength of religious identity and church attendance; strong Catholics attend Mass more often than Catholics as a whole with the same trend being apparent for Protestants.  However, strong Catholic respondent's attendance (regular attendance being described as attendance once a week to Mass) has been waning, falling from 85% in 1974 to 53% in 2012.  Protestant fluctuations do not reveal any strong trends, with 55% of strong Protestants attending church once a week in 1974 and 60% in 2012.  When broken down, Protestant divisions show revealing trends.  Evangelical and Black Protestants identify with strong religious identities (57% and 69%, respectively).  Only 35% of Mainline Protestants claim strong religious identity.