From un- + sophisticated.

unsophisticated

1. Not sophisticated; lacking sophistication.

   Synonyms: Thesaurus:naive

   • 1842, [anonymous collaborator of Letitia Elizabeth Landon], “(please specify the page)”, in Lady Anne Granard; or, Keeping up Appearances. […], volume II, London: Henry Colburn, […], →OCLC ↗, pages 31–32 ↗:

     The wonder and awe which pervaded Isabella's mind at some periods, the delight she expressed at others, her unsophisticated sentiments, her kind-heartedness, the manner in which (when she was the most moved or charmed) she wished for her sisters to partake her pleasures, were all sources of the sweetest joy to her husband, to whom she was as a dear child whom it was luxury to indulge, and amusement to develop.

• German: unkultiviert, unkompliziert