[O]ne cannot not behave. Now, if it is accepted that all behavior in an interactional situation has message value, i.e., is communication, it follows that … one cannot not communicate. Activity or inactivity, words or silence all have message value: they influence others and these others, in turn, cannot not respond to these communications and are thus themselves communicating.
Pragmatics of Human Communication: A Study of Interactional Patterns, Pathologies, and Paradoxes | Paul Watzlawick • Janet Beavin Bavelas • Don D. Jackson • Bill O’Hanlon
And in the same way that we cannot not communicate, we cannot not persuade [through design]. Whatever we do or refrain from doing, whatever we put out there as a piece of design into the world has a persuasive component. It tries to affect people.
— Sebastian Deterding
What your designs say about you | TED