Skip to main content

Divergence And Diffusion: An Analysis Of The Wave And Family Tree Models For Linguistic Change


While languages may appear to be a rather static phenomena to the outside observer, those who have looked into the intricacies of a language as it was written and spoken over a period of centuries will find that not only do languages change, but they often change drastically, absorbing new words from other languages and other dialects as contact, trade, and the advance of technology bring in new ideas and new goods that all require their own unique way of being expressed. Theoretical models like the Wave Model and the Family Tree Model have been put forward for predicting and describing the changes that occur in individual languages, but even these products of research and observation have their own unique advantages and disadvantages. Despite the fact that the Wave Model was originally devised in response to the earlier Family Tree Model and the two were at one time sharply divided by strict party loyalties, “most linguists since the end of the nineteenth century have considered them to be complimentary.” (Smith 38) Can the two models stand alone as solid opposites? Is one more suited than the other at predicting language change, or should they in fact be used in tandem, combined into a stronger, more coherent theory that better explains both the divisions that languages undergo and the way in which new traits are diffused geographically?

    Proposed by Johannes Schmidt in 1872, the Wave Model is the keystone of a theory in which it is stated that language change spreads in waves outward from central points of initial change in a series of concentric circles. (Clark 328, Fox 129) The Wave Model implies that the evolution of each individual language into its modern form is the product of the spontaneous appearance of new dialectal features (within a given language or as traits of other languages) in a given area combined with the subsequent spread of these features through contact in a wave form. It incorporates the borrowing of words that happens between languages, (such as when one culture introduces new concepts or trade goods to another) the borrowing of new linguistic features by children from their peers, and the spread of those children (with their modified dialects) to other areas (Smith, 38). Taken at face value and employed exclusively, the Wave Model ignores direct lineage and instead focuses entirely on the component parts of a language. Instead of drawing a hard line that shows one language leading to another in an unerring progression that ignores dialects and borrowings from other tongues, the Wave Model describes each language in much more detail, creating a map or diagram which tries to show the interrelationship of tongues without resorting to the direct lineage tactics of the Family Tree Model. This map of change and influence would appear at first glance as a mass of intersecting circles merging together and sliding apart, but each blending illustrated in such a map indicates a change that has occurred over time between any given language and another, creating new languages and new dialects from the blending of multiple parent tongues. These “blends” are, in truth, the strongest testaments to the statement that a language like English is in fact the “daughter” of not just a West Germanic Anglo-Frisian Dialect, but of a whole mess of unique languages and dialects within that category as well, including Central French, Norman French, Old Norse, and countless other tongues which have worked their way into any particular dialect of our current English over time, even if only in the form of a single word (like boomerang, which is from an Australian Aboriginal dialect, or karaoke, which is Japanese.) In our modern environment of rapid, global information exchange and a regular force of travel and tourism all over the world, Schmidt’s Wave Model still functions in part, but it begins to fall apart when faced with the displacement of dialectal traits that happens when one person visits or moves to a foreign country, or with the seemingly random way in which changes spread over the internet, emphasizing the fact that, in truth, not all change occurs in concentric circles or waves. As it stands, the Wave Model cannot explain the means by which some changes spread from multiple sources or stop short in the face of natural boundaries (rivers, lakes, mountains, etc.) or the way in which changes in dialect which occur through the medium of the internet (which features both written and spoken information) effect individuals in a completely random fashion (geographically speaking) and may or may not transcend from a written form to a spoken medium or vice versa. True, it could be said that, if we were to draw up a network map of cyberspace, (featuring “linguistic continents” like Myspace, Facebook, and AOL,) it might be possible to track linguistic changes to find that they do spread in a fashion similar to that of the Wave Model, but across a completely different topography with its own natural boundaries, walls between minds, walls created by a difference of language, by shyness, censorship, and intellectual bias that kill the spread of new dialectal changes before it can even occur.


    When comparing what we know of the historical record in regards to language change (that which we have sufficient information to track and analyze) to the expected outcomes that we can formulate using Schmidt’s Wave Model, we find that the idea of diffusion between languages to build new languages by a sort of blending actually holds a fair amount of water on its own. Not only is language contact a constantly-occurring process, especially in today’s world of quick, electronic communication between people worldwide, but new words are continuously being introduced into other languages as these contacts lead to a transfer of concepts or products that must be named (consider the Spanish: Computadora for “Computer” or Blog, short for Weblog, which has found its way into a number of other languages from English.) The Satem/Centum division (a division between languages that pronounce an [s] consonant or a harder [k] sound in the same place, as in Satem and Centum, two words for “hundred”) while originally noted as evidence for the Family Tree Model, as it originally created a neat division of the languages of the east from the languages of the west, has ultimately become strong evidence for the Wave Model with the discovery of languages that do not conform to this neat divide. (Renfrew 107) The fact that there are a number of shared traits between IE language groups that occurred after language division occurred (such as the fact that the past tense is based on the original perfect in both Germanic and Latin or the fact that some case-endings with -m instead of -bh occur in both Germanic and Baltoslavic tongues)(Fox 132) presents a significant argument, as does the widespread overlapping of isoglosses (Fox 129) which clearly indicates that not only do linguistic traits spread independent from one another, but they can come together to effect the same area in their steady march outward, creating areas that feature both dialectal changes while areas beyond feature only one or the other of the two. “We do know,” Says William Labov in his book, Sociolinguistic Patterns “that the growth of the affected area [i.e. the area affected by the dialectal change] may be checked by linguistic factors (Herzog 1965) or by social factors or historical discontinuities (Bloomfield 1934:344) or by the negative prestige of the group as a whole (as in the case of New York City.”(Labov 319)


    In 1871, one year before Schmidt’s Wave Model was first formulated, a German Linguist by the name of August Schleicher proposed a model for language evolution that follows a similar line as  the work of Charles Darwin by creating a sort of family tree to show descent and relatedness, with branches ultimately leading back to the trunk of an extinct common ancestor whose diversification gave rise to all of the many daughter forms we know today. (Clark 326) It is an overly simplistic model composed of “successive comparisons, creating proto-languages as we go, until we have grouped all the languages together, creating a hierarchical tree of relationships” (Fox 122-123) and in its over simplification, it makes a number of faulty assumptions, including what is probably the most grievous– that the Proto-Indo-European “trunk” of the tree existed in only a single, uniform dialect with no prior ancestor form. (Fox 133) Unlike the Wave Model, the Family Tree Model focuses wholly on direct, one way relationships, and tends to lump all dialectal forms of any given language into one single language category if the dialects are all more or less mutually intelligible. “It implies that language change is essentially a matter of language or dialect split, so that a language may have more than one descendant, but only one parent” (Fox 123) whereas the Wave Model implies a sort of diffusion or bringing together, an intermeshing of traits from numerous languages and dialects that proves, much as the flesh under any given skin color does, that there are many more similarities between us as people than there are differences.


    When placed side by side, it becomes clear that both the Wave Model and the Family Tree Model have their uses, their strong points, and their inevitable pitfalls. While the Family Tree focuses primarily on the divergence and downward division of languages, drawing hard, unswerving lines that chart the descent of what has occurred in the most simplistic of approaches, Schmidt’s Wave Model is oriented more toward tracking the diffusion of traits outward from a central source, following how they migrate, change and interrelate, creating hybrids that are recognized for their numerous and mixed parentage.(Bynon 194) It is the Model not of what has already happened (in the broadest sense), but rather of how it happened and of how it may happen again. It is a tool for predictions, showing us how the new dialectal changes of today or the as yet unimagined traits of tomorrow may spread and change our languages, whereas the only prediction you can really draw by using the Family Tree Model is that any given language may one day sprout its own daughter forms, if it does not go extinct first. “We could easily prefer a combination of the two models” says Colin Renfrew, “where there was some splitting from an original proto-language, involving some displacement of people, followed by the addition of subsequent effects by the wave mechanism”(Renfrew 106). Together, the two models can be used to offer a feasible way to explain exactly how the divisions we see in the Family Tree Model might have happened, what separated one tongue from another so much that the two became no longer mutually intelligible, indeed how the very diffusion of changes triggered the division between dialects into new daughter tongues of a parent language.

Scroll to Continue

    There is certainly proof that languages evolve and spawn in a linear fashion very much like a Family Tree pattern, one feeding into another, and although I find myself most convinced by the much more in-depth way of looking at things incorporated into the Wave Model, I feel that it’s safe to say that only when the Wave Model and the Family Tree Model are put together in a sort of hybrid do they explain and allow us to predict (to a degree) the features of language change in the most reasonable fashion. What I would like to propose is a new Model, one that charts language change in depth (as per the Wave Model) in a three dimensional form which describes not only geographical information, but also the passage of time, down to the level of dialects, so that we can see exactly who talked how and when, similar to what William Labov mentions when he suggests a “new version of the wave model of linguistic change” which “would show symmetrical distributions through time, space, and society.(Labov, 266) Granted, a lot of the data necessary for such a detailed Model has been lost over time, but with technology where it is now, I could easily see this model going into effect with our current level of information and paired up with widespread observation and data collection to map out and retain a list of the changes that take place in our languages today, tracking how change develops and spreads in an attempt to be able to draw new and more flawless predictions about the future of each language spoken in the world today.

Works Cited:

Bynon, Theodora. Historical Linguistics. Cambridge University Press. October 28, 1977

Clark, Virginia. Language: Introductory Readings. Bedford/St. Martin's; 7th edition. December 27, 2007

Fox, Anthony. Linguistic Reconstruction: An Introduction to Theory and Method. Oxford University Press, USA, April 27, 1995.

Labov, William. Sociolinguistic Patterns, illustrated edition. University of Pennsylvania Press, 1972.

Renfrew, Colin. Archaeology and Language: The Puzzle of Indo-European Origins. Cambridge University Press, January 26, 1990.

Smith, Jeremy. An Historical Study of English. Routledge, November 7, 1996


Colin Markwick on April 16, 2013:

A very well written piece. You touch upon a lot of aspects that need to be understood. In terms of using the two models together, I think it goes a little deeper than that. I think that the two models need to be used in context. I believe that the idea of linear descent is due to the presence of Latin within Europe, and that the nature of the use of Latin is important. Not only was it an authority language (which would ensure greater drift toward it) it was also what I would term an Imperial language. What I mean by that is that one's place in the Empire was predicated upon the ability not just to speak, but also to read Latin.

Within that we should also take into account that Classical Latin (the Latin of the Empire) was itself a dialect of the language of Latium, and even of Rome. It was, in fact, a sociolect. When vulgar Latins are spoken of, therefore, they should be seen as having converged toward, rather than diverged from Classical Latin - and in the same way we should be clear about the positioning of any written language within its context. An example of this is my own language, English. Even with mass media, even with hundreds of years of Standard English, accents - and small scraps of dialect - still predominate.

Another question would be, why have certain dialects/languages survived in spite of intrusive authority and Imperial languages - Welsh, irish, Basque, Frisian, Catalan etc.? Is it isolation(social and/or geographical), or is it through cultural pride? Or a combination of these?

In short, really, what I'm saying is that linguistic models cannot operate in a vacuum. They have to work within the context of their time and place. Perhaps, linguistics may help to form that context - or at least form the appropriate questions.

R C M on October 18, 2011:

this was too helpful to me. thank you so much

Vivian Gomez from Woodside, NY on February 20, 2011:

Thoroughly researched and informative. Great Hub.

Related Articles