On the Natural Selection of Words

New research suggests that languages evolve a lot like organisms do.

More dynamic than it looks.

Photographer: Hugh Pinney/Getty Images

Which would you choose, sneaked or snuck? My first instinct when faced with this question was to worry about which was correct. While sneaked sounds vaguely more grammatically correct, snuck sounds natural.

The person who posed the question to me wasn’t a grammarian but a computational biologist named Joshua Plotkin. And he wasn’t concerned with right or wrong. To him, this was a nice example of language evolution in action — and if he’s right in a recent analysis, that process is like biological evolution in ways people hadn’t previously recognized. 

Languages, like living things, were not designed, and yet in both cases, through their evolution, structure, utility and beauty emerge. In the 1860s, soon after Darwin’s theory of evolution by natural selection was published, linguist August Schleicher defended it by pointing to the already known evolution of language.

“Analogies between language change and evolution literally go back to Darwin, though originally in the opposite direction -- Darwin invoked language change to explain biological evolution,” Harvard linguistics and psychology professor Stephen Pinker told me, commenting on the study by email. “So this paper is a debt repaid.”

This kind of analysis is likely to give grammatical purists food for thought, and may even help explain why today’s watered-down use of the word “awesome” refuses to die.

Plotkin said his analysis, published in the journal Nature, required several massive digitized databases of English writing, spanning the years from the 12th to the 21st centuries. To that, he applied the mathematical tools of population genetics -- what he’s used to study how viruses and bacteria evolve.

These organisms can evolve through natural selection but also through random changes -- a process called genetic drift. DNA copying errors lead to variations that are neither good nor bad for survival, but spread because more individuals with the mutation happened to survive and reproduce.

Plotkin says mutations that are known to have spread through this process of random drift increase their frequency with a different mathematical pattern than do mutations that spread through natural selection. For one thing, genes under the influence of random drift alone tend to oscillate in frequency -- becoming more common and then less common and then more common again.

Plotkin suspected that the same patterns would show up in language changes. Indeed, he found that a number of them followed the same pattern as genes increasing through genetic drift. Other changes in the way people use English showed a pattern similar to natural selection -- survival of the fittest -- said Plotkin, including the replacement of sneaked by snuck. (Sneaked was the predominant form before the 20th century but, love it or hate it, snuck is becoming dominant.)

With genes and word variations alike, math doesn’t necessarily tell scientists what advantage a new form has over the old. What, exactly, makes one word “fitter” than another? Simple, easy-to-remember terms usually win over irregular and complex ones, Plotkin says — but not always. Take the verb dove, which has gradually taken over from the older dived. Dived is regular -- it follows the usual rule for making verbs past tense. But dove feels right to us now.

Plotkin said he believes dove benefited from the increasing use of the word drive, with its irregular past-tense form drove. The shift happened alongside the popularity of automobiles, after all. In a similar vein, he said, English speakers used to say quitted, but now we just say quit for both past and present tense, as we say split and hit. In all these cases, rhyme may win out over reason.

Natural-selection-like patterns applied to several other kinds of changes, including the use of the word do, as in Do you want a drink? or Don’t say that, as opposed to the older Want you a drink? Or Say that not. There, said Plotkin, the change probably started because a few such uses of do snuck in at random, and people naturally started to regularize the general form.

Plotkin also looked at the history of double negatives, which are currently considered a no-no in English. (Or maybe that should just be a no.) If you were to consider it with Spock-like logic, then someone saying they don’t have no bananas would mean they do have bananas. But Spock would likely be disappointed.

Double negatives often creep in to a language for emphasis, he said. The second negative doesn’t negate the first -- it reinforces it. But once this becomes common, it loses its power of emphasis, and the usage may drift back to the single negative again. It made me wonder about the persistence of the world awesome to express what okay used to mean. Perhaps its loss of emphatic power will cause it to die — or perhaps it will just replace okay and something else will replace the original awesome.

This leaves open the question of where our evolving language is headed. Is it decaying or improving? One of the big advances Darwin made was to show that biological evolution wasn’t a ladder ascending to perfection. He understood that “fitness” is a moving target. Environments change, and living things keep adapting. Despite more than 3 billion years of evolution behind us, no life form has yet achieved perfection (except, arguably, cats).

And likewise, English may be changing without getting better or worse overall. It’s tempting to think that Shakespeare had a more beautiful, unsullied version of English to work with, but that’s probably not the case. He just possessed great skill in using the language of his time. But that doesn’t mean all styles are equally good. Pinker’s recent book on writing, “The Sense of Style,” helps readers consider the most effective ways to use language for clear, vivid communication. Another favorite of mine is “The Zen of Writing” by Ray Bradbury.

If you haven’t yet snuck out to get these books, don’t hesitate. I dove right in, and never quit learning from them.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

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    Faye Flam at

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