What term describes how open a person is in their communications with others?

The term that best describes how open a person is in their communications with others is receptiveness. Receptiveness refers to an individual's willingness to consider new ideas, feedback, and different perspectives in conversations. It encapsulates the notion of being open to dialogue and engaging with others in a manner that promotes understanding and responsiveness.

While responsiveness involves how well an individual reacts to communications from others, it does not specifically denote the openness or willingness to communicate new ideas or thoughts. Assertiveness, on the other hand, is characterized by expressing one's opinions or needs confidently and directly but does not inherently imply receptiveness to others' viewpoints. Engagement generally relates to the involvement or participation in a conversation, which, like responsiveness, doesn't exclusively address the aspect of openness in communication. Thus, receptiveness is the most appropriate term to describe the openness in communication with others.