Cooperative principle

In social science generally and linguistics specifically, the cooperative principle describes how people achieve effective conversational communication in common social situations—that is, how listeners and speakers act cooperatively and mutually accept one another to be understood in a particular way.

The philosopher of language Paul Grice introduced the concept in his pragmatic theory:

Make your contribution such as is required, at the stage at which it occurs, by the accepted purpose or direction of the talk exchange in which you are engaged.^[1]: 45

In other words: say what you need to say, when you need to say it, and how it should be said. These are Grice's four maxims of conversation or Gricean maxims: quantity, quality, relation, and manner. They describe the rules followed by people in conversation.^[2] Applying the Gricean maxims is a way to explain the link between utterances and what is understood from them.

Though phrased as a prescriptive command, the principle is intended as a description of how people normally behave in conversation. Lesley Jeffries and Daniel McIntyre (2010) describe Grice's maxims as "encapsulating the assumptions that we prototypically hold when we engage in conversation."^[3] The assumption that the maxims will be followed helps to interpret utterances that seem to flout them on a surface level; such flouting often signals unspoken implicatures that add to the meaning of the utterance.