Why Languages Change Over Time
It is clear that languages evolve and change over time, in a variety of ways. There is, for example, the the grammaticalization cycle in which languages change from isolating (in which there is one word for each language element) to agglutinative (words have multiple components that can be separated) to fusional (where single word elements can have multiple meanings) and back again to isolating.
Also, there seems to be a tendency for languages to simplify over time in some situations, while gaining in complexity in others. Some linguists speculate that this is due to the dual pressures on language, to be efficient and to convey unambiguous information.
One question is whether or not the pressure to simplify over time in some situations is primarily cultural or if there is an underlying neurological basis for the pressure to simplify. A new study attempts to address this question by surveying over 600 languages an also looking brain activity while speaking.
The researchers, Bickel at al, publishing in PLOS One, looked at a specific aspect of grammar, use of nouns that are not specific to whether the noun is the subject (doing the action) or patient (receiving the action) of the verb. Some languages, like English, use the same form of the noun. Others, link Hindi, use what is called an ergative – a grammatical marking indicating the noun is a patient and not the subject.
Bickel found that sentence structures that caused the brain to perform more work were not favored over time in their review of over 600 languages. Specifically, there was a universal human bias away from the use of ergatives in speech.
This one line of evidence will likely not settle the debate, but it does favor the notion that there are at least some inherent neurological factors that guide the evolution of languages over time. Obviously culture is still important, even dominant, but is not completely independent of inborn human neurological tendencies.
Image: shows limited distribution of languages with ergatives worldwide.