A 1995 study by Hebrew University sociologist Steven Cohen found that all forms of Jewish education improve adult Jewish identity – except for once-a-week Hebrew or Sunday school. The study found that those who attend Sunday school score lower on standard measures of Jewish identity than people who had no Jewish education at all. (But, of course, those who go to Hebrew School more often than do have more ties to their Jewish identity.)
The Impact of Varieties of Jewish Education upon Jewish Identity: an Inter-Generational Perspective
By Steven M. Cohen, Jewish Agency for Israel (JAFI), 1995
This study assesses the impact of several forms of Jewish education upon composite measures of Jewish identity for teenagers and for their parents. The analysis controls for each generation’s parents’ Jewishness as well as for other factors. All forms of Jewish education, except Sunday school, are associated with higher levels of Jewish identity in both generations. The putative effects of day school, including non-Orthodox day schools, are especially pronounced. Among adults, all forms of Jewish education, EXCEPT Sunday school, are associated with lower rates of intermarriage. The likely impact of youth groups, Israel travel on intermarriage rates are rather small.