By Philip Ball of Nature magazine

Quentin Tarantino's 1994 film Pulp Fiction is packed with memorable dialogue--"Le Big Mac," say, or Samuel L. Jackson's biblical quotations. But remember this exchange between the two hitmen, played by Jackson and John Travolta?

Vincent (Travolta): "Antwan probably didn't expect Marsellus to react like he did, but he had to expect a reaction".

Jules: "It was a foot massage, a foot massage is nothing, I give my mother a foot massage."

Computer scientists Cristian Danescu-Niculescu-Mizil and Lillian Lee of Cornell University in Ithaca, New York, see the way Jules repeats the word 'a' used by Vincent as a key example of 'convergence' in language. "Jules could have just as naturally not used an article," says Danescu-Niculescu-Mizil. "For instance, he could have said: 'He just massaged her feet, massaging someone's feet is nothing, I massage my mother's feet.'"

The duo show in a new study that such convergence, which is thought to arise from an unconscious urge to gain social approval and to negotiate status, is common in movie dialogue. It "has become so deeply embedded into our ideas of what conversations 'sound like' that the phenomenon occurs even when the person generating the dialogue [the scriptwriter] is not the recipient of the social benefits", they say.

Mirroring reality

"For the last forty years, researchers have been actively debating the mechanism behind this phenomenon," says Danescu-Niculescu-Mizil. His study with Lee, published in the proceedings of the Workshop on Cognitive Modeling and Computational Linguistics, has not pinned down whether the 'mirroring' tendency is hard-wired or learnt, but it shows that this tendency does not rely on the spontaneous prompting of another individual and the genuine desire for his or her approval.

"This is a convincing and important piece of work, and offers valuable support for the notion of convergence," says Lukas Bleichenbacher of the University of Zurich in Switzerland, a philologist and specialist on language use in film.

The result is all the more surprising given that movie dialogue is generally recognized to be a stylized, carefully polished version of real speech, serving the dictates of fiction, such as character and plot development.

"The method is innovative, and kudos to the authors for going there," says Howie Giles, a specialist in communication at the University of California, Santa Barbara.

"Fiction is really a treasure trove of information about perspective-taking that hasn't yet been fully explored," agrees Molly Ireland, a psychologist at the University of Texas at Austin. "I think it will play an important role in language research over the next few years."

But, Giles adds, "I see no reason to have doubted that one would find the effect here, given that screenwriters mine everyday discourse to make their dialogues appear authentic to audiences."

Dialogue deluge

That socially conditioned speech becomes an automatic reflex has long been recognized. "People say 'oops' when they drop something," Danescu-Niculescu-Mizil explains. "This probably arose as a way to signal to other people that you didn't do it intentionally. But people still say 'oops' even when they are alone, so the presence of other people is no longer necessary for the 'oops' behavior to occur--it has become an embedded behavior, a reflex."

He and Lee wanted to see if the same was true of convergence in conversation. To do that, they needed a seemingly unlikely situation in which the person generating the conversation could not expect any of the supposed social advantages of mirroring speech patterns. That's precisely the situation for movie scriptwriters.

So the researchers looked at the original scripts of about 250,000 conversational exchanges in movies, and analysed them to identify nine previously recognized classes of convergence.

Danescu-Niculescu-Mizil and Lee found that such convergence is clearly evident in the movie dialogues, although less so than in real life--or, standing proxy for real life, in conversational exchanges held on Twitter. In other words, the writers have internalized the notion that convergence is needed to make dialogue "sound real." "The work makes a valid case for the use of 'fictional' language data," says Bleichenbacher.

Not all movies showed the effect to the same extent. "We find that in Woody Allen movies the characters exhibit very low convergence," says Danescu-Niculescu-Mizil--a reminder, he adds, that "a movie does not have to be completely natural to be good".

Giles remarks that, rather than simply showing that movies absorb the unconscious linguistic habits of real life, there is probably a two-way interaction. "Audiences use language devices seen regularly in the movies to shape their own discourse," he points out. In particular, people are likely to see what types of speech "work well" in the movies in enabling characters to gain their objectives, and copy that. "One might surmise that movies are the marketplace for seeing what's on offer, what works, and what needs purchasing and avoiding in buyers' own communicative lives," Giles says.

Danescu-Niculescu-Mizil hopes to explore another aspect of this blurring of fact and fiction. "We are currently exploring using these differences to detect 'faked' conversations," he says. "For example, I am curious to see whether some of the supposedly spontaneous dialogues in so-called 'reality shows' are in fact all that real."

This article is reproduced with permission from the magazine Nature. The article was first published on June 24, 2011.