On average, teens from intact families with frequent religious attendance earned the highest GPA (2.94) when compared to (a) their peers from intact families with low to no religious attendance (2.75), (b) peers from non-intact families with frequent religious attendance (2.72), and (c) peers from non-intact families with low to no religious attendance (2.48).

Source: Fagan, Patrick, A Portrait of Family and Religion in America: Key Outcomes for the Common Good, (Washington, D.C.: The Heritage Foundation 2006)

(HT: FamilyFacts.org)