Coherence and Correspondence

Coherence and correspondence are lie-detection concepts advanced by J. Pete Blair of Texas State University, Torsten Reimer of Purdue University, and Timothy Levine of Korea University. They reflect two different ways of understanding what it means to be consistent. Statements can be consistent or inconsistent in different ways, and coherence and correspondence address an important distinction between types of consistency information as related to deception and deception detection. As a method of lie detection, correspondence is superior to coherence.

Coherence refers to the logical consistency within a single statement or between two or more statements. A single statement is coherent if it is not self-contradictory. Two statements are coherent if one does not contradict the other. If a person says, “Steve is my friend,” but later denies knowing anyone named Steve, his statements do not cohere. Logically, one must be false. But if the same person says, “Steve is my friend,” and then says, “Steve and I have known each other for a long time,” coherence is maintained.

Correspondence, on the other hand, refers to the consistency between a statement and some evidence or prior knowledge. A statement may be assessed to determine if it corresponds with the facts as they are known, or if it is inconsistent with the facts. Statements that contradict facts are said to lack correspondence and can be judged as objectively false, while statements that conform to evidence are true. For example, if a person says, “I don't know anyone named Steve,” but another person has seen them together often and has read research that they coauthored together, his statement about not knowing Steve lacks correspondence and can be judged false. But if the same person says that he has coauthored work with Steve, and someone conducts an Internet search that shows that he has indeed coauthored several research articles with Steve, it can be concluded that his statement is true.

The general ideas of coherence and correspondence have a long history in philosophy and science. Any theory that is true needs to be internally consistent (coherence) and consistent with known facts (correspondence). Theories that are self-contradictory or that contradict known facts are rejected and do not count as valid knowledge.