simple-minded

This term carries a heavy duality depending on the speaker's intent. In a critical or clinical sense, it describes a lack of intellectual sophistication or a naive inability to grasp complex social cues, often implying a certain slowness of mind.

Conversely, it can be used with a touch of envy or nostalgia to describe a person who is devoid of guile, cynicism, or ulterior motives. In this light, the word evokes a sense of purity and honest transparency, contrasting with the calculated complexity of a sophisticated or manipulative person.