DMT is a new theory of metaphor that is one off-shoot of the explosion in metaphor research that occurred from the late 1970s in cognitive science (including parts of philosophy, linguistics, psychology, and communication science). Metaphor was reconceptualized as a fundamental and ubiquitous part of thought instead of seeing it as a quirky and rare form of meaning in poetry, rhetoric, and other ‘deviant’ types of language use. During the eighties and nineties, metaphor became a hot topic across the cognitive and social sciences. Researchers showed that metaphor was intimately related to general aspects of language use, analogizing, categorization, and other fundamental aspects of cognition.
DMT itself arose as a result of a specific combination of new metaphor theories and findings in cognitive linguistics, psycholinguistics, and corpus linguistics. This led to the discovery of the paradox of metaphor: contrary to at least one dominant theory in modern metaphor studies (Conceptual Metaphor Theory), many metaphors are not likely to be comprehended metaphorically (Full article: The Paradox of Metaphor: Why We Need a Three-Dimensional Model of Metaphor). In order to resolve the paradox, a new three-dimensional model for metaphor was postulated, which became the basis for DMT as an alternative theory of metaphor.
DMT then gradually developed over fifteen years of research across the world in what are now several hundreds of studies (see bibliography). On the basis of this work, DMT was recently updated and elaborated into a four-dimensional model. The latest overview can be found in Slowing Metaphor Down: Elaborating Deliberate Metaphor Theory | Gerard J. Steen, and is summarized in Frontiers | Thinking by metaphor, fast and slow: Deliberate Metaphor Theory offers a new model for metaphor and its comprehension. This marks a new stage in DMT that offers new views of how the original model and the research it inspired should now be understood (see key issues in DMT).