The similarities noted between many of the languages of Mesoamerica have led linguistic scholars to propose the constitution of a sprachbund, from as early as 1959.
The proposal was not consolidated until 1986, however, when Lyle Campbell, Terrence Kaufman and Thomas Smith-Stark employed a rigid linguistic analysis to demonstrate that the similarities between a number of languages were indeed considerable, with the conclusion that their origins were very likely caused by diffusion rather than inheritance, the standard criteria for defining a sprachbund.