A recent study by Joshua Goodman, Michael Hurwitz, Jonathan Smith, and Julia Fox explores the relationship between siblings’ college choices. Using data from 1.6 million pairs of siblings who took the SAT between 2004 and 2011 they find that 31% of younger siblings apply to and 19% enroll in the same college as their older sibling. They also find that younger siblings are 16 percentage points more likely than their high school peers to enroll in four-year colleges if their older siblings do so first, and 19 percentage points more likely to enroll in highly competitive colleges if their older siblings do so. Siblings are more likely to make similar decisions if they are of the same gender, close in age, and have similar academic qualifications. However, the sibling effect is robust across a variety of family and geographic characteristics.

These findings suggest that older siblings can play a valuable role in where their younger siblings attend college. While this finding is not particularly surprising, it can have important implications for approaches to improving access to and completion of a degree. Older siblings can provide younger siblings with important information about the application process, financial aid, different types of colleges and their quality, and motivation to pursue a similar path. Michelle Obama says that “if Princeton hadn’t found my brother as a basketball recruit and if I hadn’t seen that he could succeed on a campus like that, it never would have occurred to me to apply to that school, never.”

Furthermore, if the siblings enroll in the same institution the younger sibling may be more likely to graduate because they have insider information on how to navigate the system and what they need to do to succeed. They may also feel a greater sense of belonging and have a strong support network to keep them going when they face challenges.

A few initiatives already underway have sought to replicate some benefits of strong sibling and peer effects. The College Advising Corps focuses on increasing the number of under-represented high school students who enroll in and complete college by matching them with recent college graduates who serve as advisors. The Big Brothers Big Sisters of America organization has a program that matches college graduates with high school students to guide them through the application process, similar to how an older sibling might guide a younger one. The Posse Foundation organizes students in groups of 10 peers while they prepare for and attend college so that they can rely on each other for guidance, support, and motivation. These programs represent a few ways in which knowledge about how sibling effects work can be used to improve college choices for students more broadly.

Additional research about how exactly older siblings influence younger sibling’s college choices is needed to provide insight into more general approaches that can be taken to improve college choices and completion. Once we have an understanding of the specific information and support systems that lead to higher college enrollment rates at more selective institutions, we can work on building initiatives to expand these benefits to more students. Having a clear path to college should not depend on the good luck of having a successful older sibling.