unsophisticated

a relatively unsophisticated mechanism

Critics reviled the novel as unsophisticated pulp.

The sights of Paris bowled over the unsophisticated tourists.

Under an unsophisticated culture, inartifical tastes, and an unpretending outside, lay a secrecy power and fire that might have inflamed the brain and kindled the veins of a hero;

an unsophisticated sense of humor