The study of technology is divided. There are scholars, found especially in sociology and history, who emphasize interpretive flexibility, agency and historical contingency. These I label 'mild-constructivists.' Other scholars, found especially in business, economics, military studies and macro-history, emphasize functional adaptation and 'deterministic' trends. These I label 'sociotechnical adaptationists.' A theory of sociotechnical evolution can unify the insights of these seemingly contradictory approaches to technology. Competitive processes constrain sociotechnical variation: the range of interpretations and choices available to an actor are constrained by the imperative to survive. Economic and military competition, in particular and in the long run, constrain an actor's decisions to those that promote, respectively, the profit or power of the encompassing 'social organism,' such as a firm or state.
Thomas Misa has noted that scholarship with large-scales of analysis tends to be technologically deterministic. At large scales of analysis, instances of economic and military competition are more common. I argue that economic and military competition is the mechanism that gives rise to emergent deterministic patterns. New technology "merely opens a door; it does not compel [us] to enter." It is economic and military competition that shoves us through.
Military competition tends to operate over longer time scales and constrain economic and social competitive processes. Economic competition operates over middle time scales and constrains social competitive processes. These competitive forces 'select' for economically and militarily functional sociotechnical configurations. Thus, at larger scales of analysis the competitive processes giving rise to functionalist adaptation are more apparent.
A unified theory of sociotechnical evolution can reconcile the detailed micro-narratives of mild constructivism with the functionalist insights of the adaptationists. Almost all theories of technology are appropriate in their proper analytical context, defined by the character of variation (in particular, the degree of path dependency) and the kinds of competitive processes present.
There are, however, two approaches to technology which cannot be reconciled within a theory of sociotechnical evolution. They are radical social constructivism and na?ve technological determinism. Scholars in the first group claim that there is unlimited interpretive flexibility, agency and contingency. Scholars from the latter group naively attribute agency to technology, failing to acknowledge the absence of a micro-theory for their claims.

The history of Japan's use of firearms provides an illustration of the utility of the sociotechnical evolution framework. The introduction of firearms into Japan, beginning in 1543, follows the adaptationist script: two firearms arrived with some Portuguese adventurers, were bought, reverse engineered, and soon produced and used in the hundreds and then thousands.
From the 1600s to 1853, though, Japan's use and development of firearms stagnated. Constructivist scholars could productively explore the social reasons for this 'reversion to the sword.' Their findings are bounded, though, by the conditions that characterized this period, namely: the absence of internal and external military competition.
In 1853 Commodore Perry's ultimatum ended this 250 year 'retrogression' by imposing a painful imperialist challenge. Japan could no longer maintain its isolation without risking following the fate of China in the Opium Wars. Japan's ensuing industrialization and modernization poses a problem for both constructivist and adaptationist theories of technology. Japan eventually adopted superior Western military technologies, but not in the simple functionalist way that an adaptationist would expect. A satisfying history requires an appreciation for both the cultural and military context, and the ways that they interact.