The Unexpected Skill That Predicts Graduate School Success
A long-term study of doctoral students identifies the single behavior that most reliably distinguishes those who finish from those who do not. It is not what most applicants emphasize.
Graduate school admissions committees evaluate candidates on a familiar set of measures: undergraduate GPA, standardized test scores, research experience, recommendation letters, statements of purpose. A 2025 longitudinal study from the Council of Graduate Schools suggests that none of these factors predict doctoral completion as well as a single behavior that most application materials do not assess.
The study followed 4,200 PhD students across 28 US universities from admission through eight years of progress. The strongest predictor of degree completion was the consistency with which students kept structured weekly writing sessions during their first three years.
The Writing Habit Finding
Students who maintained at least four writing sessions per week, of at least 60 minutes each, for the first three years of their programs completed their doctorates at rates roughly twice those of students who wrote less consistently. The finding held across humanities, social sciences, and STEM disciplines, though the form of writing varied: in humanities, writing meant drafting prose; in STEM, it often meant writing analyses of experiments, conference abstracts, or methods sections.
The consistency mattered more than the volume. Students who wrote prolifically in bursts and then paused for weeks fared worse than students who wrote modestly but regularly. The cumulative effect of regular writing was substantial productivity by the end of the third year, while burst writers often had less to show.
Why Writing Predicts Completion
The Council of Graduate Schools researchers offered several explanations. Writing is the work that produces the deliverables of doctoral programs, including conference papers, journal articles, and ultimately the dissertation. Students who develop the habit of writing produce these deliverables. Students who treat writing as something to be done when inspiration strikes or when deadlines force it tend not to produce enough.
Writing also clarifies thinking. Students who write regularly identify gaps in their ideas earlier than students who do not. They can address the gaps before they have invested significant time in flawed approaches. The earlier feedback loop produces stronger work.
The Loneliness Factor
Beyond the productivity argument, the study identified an emotional benefit. Doctoral programs are often described as isolating, and the lack of structured daily activity contributes to the isolation. Students who maintain writing schedules build structure into their weeks that approximates the structure of professional work. The structure itself appears to support persistence.
“Students who write every morning have a job,” said Dr. Eleazar Velazquez, who co-authored the study. “Students who wait for the right time to write often discover that the right time never arrives. The job versus no-job distinction matters psychologically as well as productively.”
What Programs That Encourage Writing Look Like
A subset of doctoral programs explicitly structures writing into students’ weeks. The University of Chicago’s history department holds weekly writing groups where students bring works in progress. Several research universities have established dissertation writing rooms where students reserve time and write in shared silence. Some advisers require weekly written updates regardless of how complete the work is.
Students in programs with these structures completed their degrees at higher rates than students in programs without them, even controlling for other factors. The structure does work that motivation alone often does not.
What Did Not Predict Completion
Several factors that students often emphasize during applications did not strongly predict completion. Undergraduate GPA above 3.5 had little additional predictive power. Standardized test scores were weakly predictive at best. Research experience in undergraduate years did not reliably predict doctoral completion, though it sometimes predicted earlier productivity.
The factor that did predict completion among admitted students was prior demonstrated writing habit. Students whose undergraduate work showed evidence of sustained writing practice (for example, multi-semester thesis projects, substantial writing in part-time work, or published essays) completed doctorates at higher rates than students with stronger test scores and grades but less writing history.
Implications for Applicants
The research has implications for prospective graduate students. The skill that doctoral programs most need is not what application requirements emphasize. Students who plan to apply to doctoral programs would do well to develop regular writing habits during their undergraduate years and to structure their applications to demonstrate these habits.
“If I were advising my younger self,” said Dr. Velazquez, “I would say spend less time worrying about GRE scores and more time writing every morning for four years. The first investment changes a number on an application. The second changes how you work, and the change persists.”
Implications for Programs
The research also has implications for how doctoral programs structure their requirements. Programs that build writing structure into students’ weeks (through writing groups, accountability partners, required updates) produce stronger completion rates than programs that leave the writing schedule entirely to students. The structural intervention is inexpensive and produces measurable benefits.
Few programs have made these changes systematically. The ones that have tend to be programs where senior faculty take pedagogy of doctoral training seriously. The programs that have not made the changes typically rely on the assumption that students will figure out the habit on their own. The 2025 data suggests that most students will not, and that the cost of the assumption is high.
The Practical Takeaway
For doctoral students who are currently struggling, the most useful intervention is often the simplest. Establish a writing schedule. Stick to it for two months. Write whether the writing feels productive or not. The habit will produce results that motivation alone rarely does. The students who have completed their degrees rarely cite breakthrough moments. They cite consistent work over years, which writing schedules make possible.
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