Edward Teller once said, “Von Neumann would carry on a conversation with my 3-year-old son, and the two of them would talk as equals…” He added that he sometimes wondered whether von Neumann used the same principle when speaking to everyone else.
That is a remarkable form of intelligence.
Most people are lazy, and worse, ignorant. Ignorant of the fact that the way they understand something is not how other people understand it. There can be language barriers, context gaps, the curse of knowledge, and wildly different levels of abstraction between two minds. Two people can hear the same words and construct entirely different things in their heads, while being equally convinced that their understanding is exclusively the correct one.
The mark of an intelligent person, then, is the effort they put into closing this gap. How should this be framed? At what level of abstraction? How much context is missing? How much information should be shared? Which examples will work? What can be left unsaid? Is the other person understanding anything at all? And are they understanding what was actually intended? That is the effort communication requires.
It is also worth knowing when the gap simply cannot be closed. Sometimes, no framing will work, the context cannot be transferred, or the other person is plainly unwilling to receive your thoughts due to their biases. In those cases, I have found that it is often more beneficial to just shut up.