Meta-communication is a secondary communication (including indirect cues) about how a piece of information is meant to be interpreted. It is based on the idea that the same message accompanied by different meta-communication can mean something entirely different, including its opposite, as in irony. The term was brought to prominence by Gregory Bateson to refer to "communication about communication", which he expanded to: "all exchanged cues and propositions about (a) codification and (b) relationship between the communicators". Meta-communication may or may not be congruent, supportive or contradictory of that verbal communication. Gregory Bateson invented the term in 1951. Bateson suggested the significance of metacommunication in 1951, and then elaborated upon one particular variation, the message "this is play," in 1956. A critical fact for Bateson was that every message could have a metacommunicative element, and typically, each message held metacommunicative information about how to interpret other messages. He saw no distinction in type of message, only a distinction in function. Some metacommunicative signals are nonverbal. The term kinesics, referring to body motion communication and occasionally employed by Bateson, was first used in 1952 by Ray Birdwhistell an anthropologist who wished to study how people communicate through posture, gesture, stance, and movement. Part of Birdwhistell's work involved filming people in social situations and analyzing them to show different levels of communication not clearly seen otherwise. Birdwhistell's research was influenced by Margaret Mead and Gregory Bateson; all three were participants in the Macy Conferences in Group Processes, and both Birdwhistell and Bateson were part of a later multidisciplinary collaboration, The Natural History of an Interview. From 1952–1962, Bateson directed a research project on communication. This paid particular attention to logical paradoxes including Russell's paradox 1901 and to Bertrand Russell's Theory of Types, Russell's solution to it.