Citation
The small world problem
TL;DR
Median chain length of 5 intermediate people between random strangers in U.S.
Original small world experiment that sent letters through acquaintance chains from Nebraska to Boston, finding a median of 5 intermediate links - laying empirical groundwork for the 'six degrees of separation' concept (though Milgram never used that phrase). This demonstrated that social networks have surprisingly short path lengths despite their size.
The experiment provided the phenomenological foundation that Watts and Strogatz later formalized mathematically, showing that small-world properties aren't just mathematical curiosities but real features of human social networks.
Key Findings from Milgram (1967)
- Median chain length of 5 intermediate people between random strangers in U.S.
- Social networks exhibit short path lengths despite vast size
- Provided empirical evidence for 'small world' phenomenon later formalized by Watts-Strogatz