Time to PhD completion is no different between men and women despite score gap on physics GRE

Using analysis of variance on a sample consisting of 1,499 US students across 21 US PhD programs, we show that there is no significant difference in the time it takes US male and female physics PhD students to complete their degree programs. This result comes in spite of a statistically significant 18 percentile point gap in median GRE-P scores between genders. Additional analyses reveal that there is no statistical difference between US students reported as White, Black/Hispanic/Multiracial/Native American, and Asian. Expanding our sample to also include 1,143 Non-US students, we find a small but significant effect of citizenship status on time to PhD completion where the average time for Non-US students to complete a physics PhD is about two months less than their US student counterparts. These results show that in spite of known gaps in standardized admissions exams between genders, these differences are not reflected in subsequent graduate school performance. Our findings reinforce the need for graduate admissions committees to go beyond quantitative metrics and conduct a holistic assessment of an applicant's potential to perform research effectively and to earn a PhD.