Kids living with their married biological parents are more likely to finish high school and graduate college than kids from other kinds of families—and that’s not only, or even primarily, because their families are wealthier. New research from Canada suggests that gaps in college enrollment and completion between young people from different family types stem less from their parents’ socioeconomic status and involvement than from their own academic performance, engagement at school, and aspirations.

Using detailed longitudinal data from the Canadian Youth in Transition Survey, researchers Zheng Wu, Christoph M. Schimmele, and Feng Hou followed more than 10,000 people born in 1984 from age 15 to age 26. They examined how a multitude of factors shaped the young adults’ likelihood of having enrolled in a four-year college or university by age 21 and having attained a degree by age 26. Family structure was measured at age 15 and fell into one of six categories based on the number of parents present, the parents’ marital status, and their biological relationship to the child. (Children living apart from their parents—e.g. with grandparents or foster parents—all fell into one “other” category.)

Other measured characteristics included the young person’s demographics (gender, immigrant status, metropolitan/urban/rural background); parental education, parental occupational status, and household income adjusted for family size; several characteristics of the school the child attended at age 15; parental behaviors such as homework supervision, frequency of discussing school with their child, preparing financially for college, and monitoring and nurturance behaviors, all when the child was 15; and finally, the child’s academic characteristics and educational/professional aspirations at age 15. At the risk of overwhelming you with detail, the child’s academic characteristics included measures like the number of hours spent on homework, grade point average, math and literacy skills, and whether the child’s peers plan to continue their education after high school.

After crunching the numbers for male and female students using logistic regression analysis, Wu et al. performed a decomposition analysis to show how much each variable contributed to family structure–related gaps in educational attainment. The results varied somewhat by outcome (university enrollment vs. university completion), student gender, and particular family type, but in general, the child’s academic characteristics and aspirations together accounted for about 60 percent of the gap in educational attainment between those from married, biological-parent families and those from other family types. Parents’ socioeconomic status, parents’ behaviors, and the child’s demographics accounted for varying portions of the rest of the gap (roughly 10 to 25 percent a piece in most cases), while school attributes mattered hardly at all. Female students from each family structure type vastly outperformed their male peers; in fact, the young women from single-parent families, while lagging behind women from married, biological-parent families, had college enrollment and completion rates similar to those of men from married, biological-parent families, the researchers observed.

So how would family structure affect kids’ grades and educational aspirations? Wu, Schimmele, and Hou attribute it to “academic socialization,” or “the family’s ability to instill values in children about the importance of education,” and thus to shape their academic efforts and plans. The superior socioeconomic status and social capital of married, biological-parent families better equip them to fulfill this role: they may have more books in the house, visit more museums, live in better neighborhoods, et cetera. While parents’ socioeconomic status and behaviors did not have major direct effects on teens’ eventual educational attainment in the study, that is, they could be indirectly relevant insofar as they shaped kids’ lasting attitudes toward school.

But there is good news here for disadvantaged parents, who could easily be discouraged by studies on how their lack of resources hurts their kids: Citing other work, Wu and his colleagues note that “Parental expectations are a stronger determinant of children’s aspirations than parental education or household income. When communicated on a regular basis, high expectations socialize children into valuing education. . . . Students who perceive that their parents place a high value on education tend to respond with positive academic behaviors.”