Background: Scientific progress during doctoral studies is a combination of individual effort and teamwork. A recently growing body of interdisciplinary literature has investigated the determinants of early career success in academia, in which learning from supervisors and co-authors play a great role. Yet, it is less understood how collaboration patterns of the research team, in which the doctoral student participates, influences the future career of students. Here we take a social network analysis approach to investigate this and define the research team as the co-authorship network of the student.
Methods: We use the Hungarian Scientific Bibliography Database, which includes all publications of PhD students who defended theses from the year 1993. The data also include thesis information, and the publications of co-authors of students. Using this data, we quantify cohesion in the ego-network of PhD students, the impact measured by citations received, and productivity measured by number of publications. We run multivariate linear regressions to measure the relation of network cohesion, and publication outputs during doctoral years with future impact.
Results: We find that those students in life sciences, but not in other fields, who have a cohesive co-author network during studies and two years after defence receive significantly more citations in eight years. We find that the number of papers published during PhD years and closely after the defence correlates negatively while the impact of these papers correlates positively with future success of students in all fields.
Conclusions: These results highlight that research teams are effective learning environments for PhD students where collaborations create a tightly knit knowledge network.