credulous

This word carries a distinct tone of judgment, suggesting a lack of critical thinking or a naive openness that makes a person vulnerable. It describes a personality trait where the default setting is trust, often to a fault, leaving the individual exposed to deception. While "trusting" is generally seen as a positive virtue, "credulous" is almost always negative. It implies a failure of discernment, painting the subject as someone who accepts claims without demanding evidence or exercising healthy skepticism.