I previously talked about how changes in the demography of learners can affect the cultural evolution of a language. The hypothesis is that language adapts to the balance between declarative and procedural memory users. Since alcohol consumption affects procedural but not declarative memory (Smith & Smith, 2003), we might expect to see communities that have a high alcohol consumption using less complex morphology.
I find that communities that have a morphologically marked future tense have significantly higher alcohol consumption than communities that have a lexically marked future tense (Alcohol consumption data from WHO, language structure data from World atlas of language structures, 198 languages, t = 14.8, p<0.0001). This statistic does not take into account many factors, but is meant as a motivation for further research into language structure and social structure.
Smith C, & Smith D (2003). Ingestion of ethanol just prior to sleep onset impairs memory for procedural but not declarative tasks. Sleep, 26 (2), 185-91 PMID: 12683478