Following in a Sibling's Footsteps

The college enrollment decisions of older siblings could be an important cue to whether and where their younger siblings attend college, according to a new study by researchers from Harvard University and the College Board.

Ultimately, the research aims to determine the power of peers’ decisions on college enrollment, and siblings are the easiest peers to identify in available data.

The study found that 69 percent of younger siblings enrolled in the same type of college as their older sibling (either a two-year or four-year institution), while 31 percent of younger siblings applied to the college their older sibling attended.

Most impressive to the researchers was that about 20 percent of younger siblings actually enrolled at the same college as their older sibling.

The positive relationship between older and younger siblings’ college choices was similar across demographic groups and was stronger between siblings who resemble each other more in academic skills, age or gender. That suggests the relationship between siblings’ college choices may be more than a simple coincidence, said Joshua Goodman, an assistant professor of public policy at Harvard’s John F. Kennedy School of Government.

Goodman, along with Michael Hurwitz, Jonathan Smith and Julia Fox, all of the College Board, were shocked to find there was almost nothing written about siblings and college choice, Goodman said. The College Board administers the SAT exam.

The team analyzed 1.6 million pairs of siblings who took the SAT between 2004 and 2011. The researchers identified siblings by matching the last name and home addresses on SAT forms, and mapped their college enrollment based on data from the National Student Clearinghouse and the Education Department's Integrated Postsecondary Education Data System.

In some ways, the study measures a notion people may take for granted: that it’s common to follow an older sibling’s footsteps through higher education.

Likewise, there are often anecdotal accounts of elder siblings from disadvantaged backgrounds getting into school and serving as a source of inspiration for their younger siblings.

But, Goodman said, it’d be nice to have data to back up those assumptions, particularly if there’s evidence to show there are ways to change the college-going rates of groups of students by providing them with models of people who’ve gone to college.

“There are certain schools and communities where college-going is not common,” Goodman said. “So if you change one set of kids’ outcomes, it may have a spillover effect to the rest of the community.”

Possible Reasons Why

One explanation for the positive correlation between siblings’ college choices could be that older siblings essentially lower the costs of navigating the college admissions process, Goodman said. They can share information about filling out admissions applications, applying for financial aid, and so on.

On the other hand, the findings could be explained through legacy policies, where colleges are more likely to admit students from the same family or to offer tuition discounts to family members.

“Some of this relationship is driven by those things,” Goodman said. “I’m skeptical that they can explain why a fifth of younger siblings attend the same college as their older siblings, though.”

Proximity is another possible explanation the researchers think they ruled out. They questioned whether siblings were more likely to attend the same college if they lived near that institution. But the data show no difference in the choices of pairs of siblings who live in college-dense areas versus areas without nearby campuses.

There’s also no significant difference between white siblings compared with black and Hispanic siblings, and between siblings of families that earn less than $50,000 and those that earn more.

The data also show the quality of college selected by an older sibling is strongly predictive of the quality chosen by a younger sibling. Goodman said that information could be used to improve targeted interventions to get students to apply to college or apply to a college that’s a better fit.  

It’s difficult to predict which students are planning to apply and which may attend a college for which they’re poorly matched, Goodman said. But using an older sibling’s choice as an indicator of what the younger sibling is planning to do can slightly reduce the likelihood of error, according to the study.  

So if a high school guidance counselor knows, for example, that a student’s older sibling applied to a college beneath his or her academic level, the counselor may want to focus more on that student, Goodman said.

That could be particularly helpful for placing disadvantaged students, given research that shows high-achieving low-income students do not apply to or enroll at the same quality colleges as their higher-income peers.

“Regardless of how exactly you interpret these results, it’s clear that families play an extremely important role in the college enrollment decision,” he said.

Pathways for Future Research

Right now, the authors are looking for data to back up Goodman’s sense that the relationship isn’t coincidental.

One method they’re using is to analyze the decisions of siblings in Georgia, which has a statewide cutoff SAT score to attend public four-year institutions. Being just above the threshold means a student is much more likely to go to a four-year college, Goodman said.

So Goodman and his team are taking sets of two nearly identical older siblings, one who just barely made the cutoff and one who fell below it, and comparing each of their college choices with that of their younger siblings to see if there’s any difference.

In preparing for this research, one study Goodman did find about siblings’ influence on each other’s behavior related to alcohol and smoking. It suggests an older sibling's delinquent juvenile behavior can influence a younger sibling.

This research, Goodman said, may be a more positive angle on the power siblings have to influence one another.