Previous research has found that words are replaced faster in language vocabularies the less the word is used, whereas words that are used more frequently endure longer. Drawing from this theory, the authors of this article propose two questions: 1) Is the rate of replacement for Indo-European kinship terms correlated with their usage frequency? 2) How does this relationship differ between kinship terms and core vocabulary? Using phylogenetic comparative methods to analyze 10 kinship categories from 47 Indo-European languages, the authors find that more frequently used kinship terms tend to be replaced at a much slower rate than less frequently used words. Furthermore, this relationship between word replacement rate and usage frequency is stronger for kinship terms than it is for core vocabulary terms.

This article examines the universal tendency for languages, regardless of their historical relationships, to develop similar words for mother and father on the basis of nursery forms. Findings suggest that Ma, Na, Pa, and Ta are significantly more common sound classes denoting the mother or father.

This study sampled over 4,012 language varieties, comparing their version of 40 generally universal words, such as body parts, water, the sun, pronouns, and common behaviors or animals. These language variations were tested in their association to "specific humidity," the variable used to represent ambient humidity of a language location. Results suggest negative association between the dryness of climate and the utilization of vowels, consitent with the idea that dry air affects the behavior of the larynx.

This study examines whether language construction, specifically the number of consonant-vowel syllables, will be related to the environment and literacy of a society. Empirical analysis suggests that consonant-vowel syllables are more common in warmer climates and less common in written languages.

Scholars generally agree that, across languages, the relationship between particular sounds and the meaning of words is arbitrary. In this article the authors test this assumption, seeking patterned associations between sound and meaning in the basic vocabulary lists of a large, worldwide sample of languages.

This paper examines the Berlin-Kay color salience theory and offers four correlates of color salience: earliness of introduction, brevity of expression, frequency of use, and frequency of mention in ethnographic literature. All four correlations support the Berlin-Kay theory. The authors suggest that salience may be “an important general principle of cultural evolution” (1107).

Authors hypothesize that grammatical sex gender may be related to social structural variables. Results support this hypothesis and suggest that the degree of sex bias in the social structure is associated with the relative frequency of masculine and feminine nouns in languages with sex gender.

Population size is generally assumed to play a pivotal role in the evolution of languages and cultures, but the expected patterns and potential mechanisms of change are unsettled. Theoretical models are limited by this uncertainty because they require making prior assumptions about language evolution. Using a sample of 20 Polynesian languages, authors test the effect of population size on the gain, loss, and total change of basic vocabulary words.

Using ethnography, historical linguistics, paleoanthropology, and speech biomechanics, the present study examines the relationship between labiodentals and the post-Neolithic period with the introduction of agriculture and softer diets. The results offer support for the linguist, Charles Hockett's, hypothesis that the shift in bite configuration in the post-Neolithic period, as well as the persistence of overbite and overjet, facilitates and makes the articulation of labiodentals more prevalent. Using cross-cultural comparison, findings also reveal that societies that produce their food are more likely to evolve and keep labiodentals than those that are not food-producing. Contact with other societies is also a mode by which societies gain labiodentals. Lastly, the expansion of agricultural and food processing technology over time has been imperative to labiodental articulations.

The research presented in this book challenges the notion that languages develop color terms independently of other languages. Authors find a universal inventory of eleven basic color categories from which the basic color terms are drawn. Authors also find an apparent fixed sequence of evolutionary stages through which a language must pass as its color vocabulary increases. A postive correlation between cultural complexity and complexity of color vocabulary is observed.