The authors compare language phylogenies and spatial distributions with folktale frequencies of Indo-European peoples in order to reconstruct their cultural transmission. A stronger association is found between folktale frequency and language phylogeny than has been proposed in earlier literature studies, indicating that vertical transmission is more influential on folktale distribution than horizontal transmission through spatial proximity. Finally, the frequencies of certain folktales appear to trace the ancestral divergences of Indo-European languages to a much deeper level than previously though, suggesting that folktales are representative of broader features of culture, rather than recent literary inventions.

The authors statistically test existing theories and proposals regarding the existence and nature of the creole language profile. Results indicate that consistencies and variation between creole languages, as with non-creole languages, is a result of genealogical and contact processes. However, creole languages are unique from non-creole languages in that they have more than one language in their ancestry. Findings "call into question the existence of a pidgin stage in creole development and of creole-specific innovations." Support is found for the idea that language learning and transmission are strikingly resilient processes.

Is grammatical complexity shaped by sociodemographic and sociolinguistic factors? The previously accepted "linguistic niche hypothesis" claims that with an increased number of nonnative speakers in a social group (high exotericity), grammatic complexity decreases; on the other hand, grammatical complexity increases amongst isolated linguistic communities (low exotericity). Through the use of spatiophylogenetic modelling of 1314 languages, the authors of this study do not find adequate evidence to support the linguistic niche hypothesis. Instead, they suggest that linguistic complexity is better predicted by phylogeny and geographic contiguity.

This paper discusses a cross-cultural study comparing features of grammatical structure and features of social structure. The author hypothesizes that the language will emphasize "self" with more personal protection within a society.

The researchers test the relationship between toolkit complexity and diversity as defined by Oswalt (1973) and environmental and demographic variables. Neither population size nor risk of resource failure predict toolkit characteristics among all groups in the sample. However, population size is significantly positively correlated with toolkit diversity and complexity among food-producers, whereas environmental factors indicating risk of resource failure are significantly positively correlated among hunter-gatherers. This leads the researchers to suggest that food-producers' effectiveness at niche construction is a result of their large population size, which thus has a larger effect on toolkit composition than does environmental risk relative to hunter-gatherers.

Is grammatical complexity shaped by sociodemographic and sociolinguistic factors? The previously accepted "linguistic niche hypothesis" claims that with an increased number of nonnative speakers in a social group (high exotericity), grammatic complexity decreases; on the other hand, grammatical complexity increases amongst isolated linguistic communities (low exotericity). Through the use of spatiophylogenetic modelling of 1314 languages, the authors of this study do not find adequate evidence to support the linguistic niche hypothesis. Instead, they suggest that linguistic complexity is better predicted by phylogeny and geographic contiguity.

The authors statistically test existing theories and proposals regarding the existence and nature of the creole language profile. Results indicate that consistencies and variation between creole languages, as with non-creole languages, is a result of genealogical and contact processes. However, creole languages are unique from non-creole languages in that they have more than one language in their ancestry. Findings "call into question the existence of a pidgin stage in creole development and of creole-specific innovations." Support is found for the idea that language learning and transmission are strikingly resilient processes.

The authors statistically test existing theories and proposals regarding the existence and nature of the creole language profile. Results indicate that consistencies and variation between creole languages, as with non-creole languages, is a result of genealogical and contact processes. However, creole languages are unique from non-creole languages in that they have more than one language in their ancestry. Findings "call into question the existence of a pidgin stage in creole development and of creole-specific innovations." Support is found for the idea that language learning and transmission are strikingly resilient processes.

Researchers investigated further into why and how humans speak so many languages across the globe, and why they are spread out unevenly. Using two different path analyses, a Stationary Path analysis and a GWPath, researchers tested the effect of eight different factors on language diversity. Out of the eight variables (river density, topographic complexity, ecoregion richness, temperature and precipitation constancy, climate change velocity, population density, and carrying capacity with group size limits), population density, carrying capacity with group size limit, and ecoregion richness had the strongest direct effects. Overall, the study revealed the role of multiple different mechanisms in shaping language richness patterns. The GWPath showed that not only does the most important predictor of language diversity vary over space, but predictors can also vary in the direction of their effects in different regions. They conclude that there is no universal predictor of language richness.

The authors compare language phylogenies and spatial distributions with folktale frequencies of Indo-European peoples in order to reconstruct their cultural transmission. A stronger association is found between folktale frequency and language phylogeny than has been proposed in earlier literature studies, indicating that vertical transmission is more influential on folktale distribution than horizontal transmission through spatial proximity. Finally, the frequencies of certain folktales appear to trace the ancestral divergences of Indo-European languages to a much deeper level than previously though, suggesting that folktales are representative of broader features of culture, rather than recent literary inventions.