  Mentoring is a key component of scientific achievements, contributing to
overall measures of career success for mentees and mentors. A common success
metric in the scientific enterprise is acquiring a large research group, which
is believed to indicate excellent mentorship and high-quality research.
However, large, competitive groups might also amplify dropout rates, which are
high especially among early career researchers. Here, we collect longitudinal
genealogical data on mentor-mentee relations and their publication, and study
the effects of a mentor's group on future academic survival and performance of
their mentees. We find that mentees trained in large groups generally have
better academic performance than mentees from small groups, if they continue
working in academia after graduation. However, we also find two surprising
results: Academic survival rate is significantly lower for (1) mentees from
larger groups, and for (2) mentees with more productive mentors. These findings
reveal that success of mentors has a negative effect on the academic survival
rate of mentees, raising important questions about the definition of successful
mentorship and providing actionable suggestions concerning career development.
