Does Lateral Transmission Obscure Inheritance in Hunter-Gatherer Languages?

In recent years, linguists have begun to increasingly rely on quantitative phylogenetic approaches to examine language evolution. Some linguists have questioned the suitability of phylogenetic approaches on the grounds that linguistic evolution is largely reticulate due to extensive lateral transmission, or borrowing, among languages. The problem may be particularly pronounced in hunter-gatherer languages, where the conventional wisdom among many linguists is that lexical borrowing rates are so high that tree building approaches cannot provide meaningful insights into evolutionary processes. However, this claim has never been systematically evaluated, in large part because suitable data were unavailable. In addition, little is known about the subsistence, demographic, ecological, and social factors that might mediate variation in rates of borrowing among languages. Here, we evaluate these claims with a large sample of hunter-gatherer languages from three regions around the world. In this study, a list of 204 basic vocabulary items was collected for 122 hunter-gatherer and small-scale cultivator languages from three ecologically diverse case study areas: northern Australia, northwest Amazonia, and California and the Great Basin. Words were rigorously coded for etymological (inheritance) status, and loan rates were calculated. Loan rate variability was examined with respect to language area, subsistence mode, and population size, density, and mobility; these results were then compared to the sample of 41 primarily agriculturalist languages in [1]. Though loan levels varied both within and among regions, they were generally low in all regions (mean 5.06%, median 2.49%, and SD 7.56), despite substantial demographic, ecological, and social variation. Amazonian levels were uniformly very low, with no language exhibiting more than 4%. Rates were low but more variable in the other two study regions, in part because of several outlier languages where rates of borrowing were especially high. High mobility, prestige asymmetries, and language shift may contribute to the high rates in these outliers. No support was found for claims that hunter-gatherer languages borrow more than agriculturalist languages. These results debunk the myth of high borrowing in hunter-gatherer languages and suggest that the evolution of these languages is governed by the same type of rules as those operating in large-scale agriculturalist speech communities. The results also show that local factors are likely to be more critical than general processes in determining high (or low) loan rates

There are no language switching costs when codeswitching is frequent

International audienceAims and Objectives/Purpose/Research Questions: There is ongoing discussion as to the cost of language switching, with some studies indicating high cost and others showing low or no cost. The main research question in this paper is whether there are language switching costs in communities in which codeswitching is frequent. Design/Methodology/Approach: We conducted two on-line experiments, i.e. a picture choice with sentence auditory stimuli and a word recognition task in sentence context. We constructed 16 sentences with differing degrees of ecological validity (16 sentences x 4 versions = 64). The sentences included verbs with different language preferences in natural conversations (L1, L2, or both). Data and Analysis: Thirty-seven simultaneous L1-Romani L2-Turkish bilinguals participated in Experiment 1 and 49 in Experiment 2. To analyze the results, linear mixed models (lmer) were constructed using the ‘lme4’ package in R.Findings/Conclusions: In Experiment 1, participants responded significantly faster for the all-Turkish sentences, followed by the mixed Romani-Turkish sentences, and the two types of ecologically non-valid sentences. However, there were no processing costs for the mixed sentences when they contained Turkish verbs that are more frequently used in Turkish in the spontaneous conversations. In Experiment 2, reaction times were similar for Turkish verbs (with Turkish verb morphology) in a mixed Romani-Turkish or a unilingual Turkish sentence.Originality: Taken together these findings indicate that language switching costs in comprehension depend on the frequency of codeswitching in the bilingual community, as well as on exposure to specific lexical items.Significance/Implications: The Romani-Turkish data support a usage-based approach to bilingual processing and confirm the need to conduct experimental research that takes into account the communicational habits of the participants