A speech error, commonly referred to as a slip of the tongue (Latin: lapsus linguae, or occasionally self-demonstratingly, lipsus languae) or misspeaking, is a deviation (conscious or unconscious) from the apparently intended form of an utterance. They can be subdivided into spontaneously and inadvertently produced speech errors and intentionally produced word-plays or puns. Another distinction can be drawn between production and comprehension errors. Errors in speech production and perception are also called performance errors.
Speech errors are common among children, who have yet to refine their speech, and can frequently continue into adulthood. They sometimes lead to embarrassment and betrayal of the speaker's regional or ethnic origins. However, it is also common for them to enter the popular culture as a kind of linguistic "flavoring". Speech errors may be used intentionally for humorous effect, as with Spoonerisms.
Within the field of psycholinguistics, speech errors fall under the category of language production. Types of speech errors include: exchange errors, perseveration, anticipation, shift, substitution, blends, additions, and deletions. The study of speech errors contributes to the establishment/refinement of models of speech production.
Speech errors are made on an occasional basis by all speakers. They occur more often when speakers are nervous, tired, anxious or intoxicated. During live broadcasts on TV or on the radio, for example, nonprofessional speakers and even hosts often make speech errors because they are under stress. Some speakers seem to be more prone to speech errors than others. For example, there is a certain connection between stuttering and speech errors. Charles F. Hockett explains that "whenever a speaker feels some anxiety about possible lapse, he will be led to focus attention more than normally on what he has just said and on what he is just about to say. These are ideal breeding grounds for stuttering." Another example of a “chronic sufferer” is Reverend William Archibald Spooner, whose peculiar speech may be caused by a cerebral dysfunction, but there is much evidence that he invented his famous speech errors (spoonerisms).
An outdated explanation for the occurrence of speech errors is the one of Sigmund Freud, who assumed that speech errors are the result of an intrapsychic conflict of concurrent intentions. “Virtually all speech errors [are] caused by the intrusion of repressed ideas from the unconscious into one’s conscious speech output”, Freud explained. This gave rise to the expression Freudian slip. His theory was rejected because only a minority of speech errors were explainable by his theory.