Type

Article

Keywords

routing algorithms, small worlds, population networks, rank-based friendships, six degrees of separation

Abstract

We live in a ‘‘small world,’’ where two arbitrary people are likely connected by a short chain of intermediate friends. With scant information about a target individual, people can successively forward a message along such a chain. Experimental studies have verified this property in real social networks, and theoretical models have been advanced to explain it. However, existing theoretical models have not been shown to capture behavior in real-world social networks. Here, we introduce a richer model relating geography and social-network friendship, in which the probability of befriending a particular person is inversely proportional to the number of closer people. In a large social network, we show that one-third of the friendships are independent of geography and the remainder exhibit the proposed relationship. Further, we prove analytically that short chains can be discovered in every network exhibiting the relationship.

Language

English

Department(s)

Computer Science

Journal or Book Title

Proceedings of the National Academy of Sciences

Publication Year

2005

DOI

10.1073/pnas.0503018102

Publisher

National Academy of Sciences

Rights Management

Carleton College does not own the copyright to this work and the work is available through the Carleton College Library following the original publisher policies regarding self-archiving. For more information on the copyright status of this work, refer to the current copyright holder.

RoMEO Color

Green

Preprint Archiving

Yes

Postprint Archiving

Yes

Publisher PDF Archiving

No

Contributing Organization

Carleton College

Format

application/pdf

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