obstinately

This adverb carries a strong negative connotation, suggesting a level of stubbornness that is unreasonable, irrational, or frustrating to others. It describes a refusal to yield that persists even when the person is proven wrong or when continuing their course of action is counterproductive.

While "persistently" can be positive (e.g., persisting in a goal), "obstinately" implies a willful blindness or a rigid adherence to a position regardless of the evidence. It is typically used in contexts of conflict, disagreement, or failure to adapt to new information.