The hidden medical school: A longitudinal study of how social networks form, and how they relate to academic performance

UK medical schools typically have over 300 students per year, making it impossible for students to know all the others well. This longitudinal cohort study measured the formation of medical student social networks and their relationship to grades. In November 2009, 215/317 (68%) Year 2 UCL medical students reported their friendships with others in their year. Multiple regression showed that students of the same sex, the same ethnic group, and in the same tutor and small groups (to which they were randomly assigned at the start of medical school) were socially closer. Taking into account absolute difference in Year 1 grades, Year 2 student pairs who were socially closer in November 2009 had more similar May 2010 grades. Individual student variables did not predict similarity in May 2010 grades after taking friendships into account. Statistical significance was assessed by comparing the regression results with 10,000 random results calculated using a quadratic assignment procedure. The results suggest that medical students chose friends of the same sex and ethnic group as themselves; but random allocation of students to tutor groups also influenced friendships. Most importantly, friendships were related to subsequent exam performance, suggesting friendship may influence learning