Societies of strangers do not speak less complex languages.

Many recent proposals claim that languages adapt to their environments. The linguistic niche hypothesis claims that languages with numerous native speakers and substantial proportions of nonnative speakers (societies of strangers) tend to lose grammatical distinctions. In contrast, languages in small, isolated communities should maintain or expand their grammatical markers.

Grammars are robustly transmitted even during the emergence of creole languages.

Most languages of the world are taken to result from a combination of a vertical transmission process from older to younger generations of speakers or signers and (mostly) gradual changes that accumulate over time. In contrast, creole languages emerge within a few generations out of highly multilingual societies in situations where no common first language is available for communication (as, for instance, in plantations related to the Atlantic slave trade). Strikingly, creoles share a number of linguistic features (the 'creole profile'), which is at odds with the striking linguistic diversity displayed by non-creole languages .