The Value of Circular Definitions: stats & graphs on structure of human language

Original paper (free): http://prx.aps.org/pdf/PRX/v2/i3/e031018

A talk by the authors: http://www.weizmann.ac.il/complex/tlusty/talks/Loops2012.pdf

Some discussions in forums suggest some possible relation with other self-referential constructs in math such as recursive functions, logical paradoxes, Godel incompleteness, etc.