Principles of language change, frequency, and language universals

I have decided to move the updating of this blog to even weekends instead of Thursdays. Thursday is very often an extremely busy day, with no time left to update or complete blogposts for publication.

In this blogpost I will continue the previous topic of principles of language change. In historical linguistics, the pricinple of the particular status of the most frequent words and grammatical forms of language is well known. The most frequent lexemes and grammatical categories are more resistant to change. Lexemes, such as kinship words, body parts, numerals, fire, water, liver, and so forth, typically preserve more archaic paradigms, that may resist change for millenia. The most frequent adverbials and particles even resist phonological erosion and change. The most frequent verbs, such as 'to be' or 'to become', are typically irregular, and archaic inflection patterns and archaic categories, such as tenses, modalities, and aspectual categories, survive in these verbal stems. On the other hand, less frequent words, such as various verbs, nouns, and adjectives, are much more frequently impacted by analogy and other types of changes that harmonize and simplify language structures, making them more easy to memorize.

However, few studies investigate this from an evolutionary perspective, using phylogenetic methods. As shown by Pagel et al (2007) there is a correlation between lexical substitution and frequency in basic vocabulary. The most frequent words have generally lower substitution rates.

Frequency is very important in explaining cross-linguistic universal patterns, among others in morphological marking hierarchies in languages. More frequent categories, such as singular (in relation to plural), agent (in relation to object), present (in relation to past), are unmarked in relation to the categories, which are marked. This theory, known as the markedness theory (which has a lot of exceptions in languages) can to a large degree be explained by frequency (Greenberg 1966, Croft 1993, 2003).

In a current study I wanted to investigate the correlation between frequency and change rates of grammar, focusing on the Indo-European family. I compiled a sample of grammatical categories of word order, nominal morphology, verbal morphology and tense and organised the properties into hierarchical pairs according to the properties of present < past, pronoun < noun, agent < object, and masculine/feminine < neuter, which are well-known, universal, hierarchial relations, observed from a large number of languages. By means of an evolutionary model (performed by Chundra Cathcart), where transititions rates between property states over a tree were were reconstructed, we extracted the average number of transitions (per 1000 years) between each grammatical property in our data. 
When the results were split up into pairs of marking hierarchy, as mentioned above, it turned out that the rates of change in the lower categories (i.e., the less frequent ones from a universal perspective), was higher. The rates of the higher categories (i.e., more frequent ones from a universal perspectives), was lower. The difference was statistically significant (p=>0.005). Even if this study is based on one family (Indo-European), 149 languages and about 100 properties only, it seems likely that frequency impacts language change also in the grammar. This explains why more frequent grammatical categories preserve more archaic patterns over time.

Text has been updated 2019-03-11