Your personality only explains about 0.2% of your friendships; the rest is just about who you happen to be standing near.
March 23, 2026
Original Paper
Understanding friendship formation with explainable machine learning
arXiv · 2603.19845
The Takeaway
Using machine learning to analyze thousands of students, researchers found that who you become friends with is almost entirely determined by your existing network of contacts. Individual traits like gender and kindness only become the primary driver in less than 1 out of every 400 social links.
From the abstract
Understanding the formation of social ties requires disentangling the roles of individual traits and local network structure. We analyse signed social relationships among 3,395 students using an interpretable machine learning model -- the Explainable Boosting Machine (EBM) -- to predict link polarity from individual attributes (prosociality, cognitive reflection, and gender) and a structural metric, triadic influence. Our results show that triadic influence overwhelmingly dominates link predicti