This euphemistic category of cultures primarily encompasses those that failed to achieve technological prominence through a lack of literacy.  Most of these never developed any formal system of writing.  Some were founded by life-forms that lacked the ability to think abstractly about visual information, while others never developed writing because they were trapped in a cycle of perpetual warfare, or other ongoing upheavals.  Others settled into lifestyles that fit comfortably with their environments, and never felt the pressure to advance their technologies.   Also included (but not without controversy) are a handful of cultures that did develop writing systems, but had written languages so simple as to only contain a handful of words.  Included in this latter group are the Wuxria, whose lack of fine manipulation abilities left their written language at a rudimentary level.