Origin and development

The Freudian slip is named after Sigmund Freud, who, in his 1901 book The Psychopathology of Everyday Life,^[1] described and analyzed a large number of seemingly trivial, even bizarre, or nonsensical errors and slips, most notably the Signorelli parapraxis.

Freud, himself, referred to these slips as Fehlleistungen^[1] (meaning "faulty functions",^[1] "faulty actions" or "misperformances" in German); the Greek term parapraxes (plural of parapraxis; from Greek παρά (para) 'another', and πρᾶξις (praxis) 'action') was the creation of his English translator, as is the form "symptomatic action".

Freud's process of psychoanalysis is often described as being lengthy and complex, as was the case with many of the dreams in his 1899 book The Interpretation of Dreams. An obstacle that faces the non-German-speaking reader is such that in original German, The Interpretation of Dreams, Freud's emphasis on "slips of the tongue" leads to the inclusion of a great deal of colloquial and informal material that are extremely resistant to translations.^[2]

As in the study of dreams, Freud submits his discussion with the intention of demonstrating the existence of unconscious mental processes in the healthy:

In the same way that psycho-analysis makes use of dream interpretation, it also profits by the study of the numerous little slips and mistakes which people make—symptomatic actions, as they are called ... I have pointed out that these phenomena are not accidental, that they require more than physiological explanations, that they have a meaning and can be interpreted, and that one is justified in inferring from them the presence of restrained or repressed impulses and intentions. [Freud, An Autobiographical Study (1925)]

Slips of the tongue

In general use, the term 'Freudian slip' has been debased to refer to any accidental slips of the tongue.^[5] Thus many examples are found in explanations and dictionaries which do not strictly fit the psychoanalytic definition.

For example: She: 'What would you like—bread and butter, or cake?' He: 'Bed and butter.'^[5]

In the above, the man may be presumed to have a sexual feeling or intention that he wished to leave unexpressed, not a sexual feeling or intention that was dynamically repressed. His sexual intention was therefore secret, rather than subconscious, and any 'parapraxis' would inhere in the idea that he unconsciously wished to express that intention, rather than in the sexual connotation of the substitution. Freudians might point out, however, that this is simply a description of what Freud and Breuer termed the preconscious which Freud defined as thoughts that are not presently conscious but can become conscious without meeting any resistance.^[6] In Freud's theory, he allows parapraxes to be generated in the preconscious,^[7] so he would allow for thoughts that one tries to put outside of consciousness to have effects on conscious actions.

Human-computer interaction

Beyond slips of the tongue, these accidental human errors also commonly occur in the realm of human-computer interaction. In the context of interaction design, slips refer to an incorrect action that is taken with the correct intention.^[8] As opposed to mistakes, which refer to an incorrect action due to an incorrect intention, slips result from automatic behaviors that are triggered by external factors, distracting the user from carrying out their intended goal. There are many different types of slips in interaction design, including capture errors, description similarity slips, data-driven errors, associative activation, loss of activation, and mode errors.

Capture errors occur when a familiar behavior takes over a less frequently occurring behavior.^[9] An example of a capture error would be driving to the office on a Saturday when the intention was to go to the grocery store.

Description similarity slips occur when an action is taken upon an item that is similar to the one you intended.^[10] For example, flipping the switch for the bathroom vent fan instead of the light switch to turn on the bathroom light would be a description similarity slip.

Data-driven errors occur in the arrival of new sensory information that triggers an automatic response, such as dialing the hotel concierge to reserve a particular room and dialing the room number instead.^[11]

Associative activation errors are caused by an internal correlation of two actions.^[11] For example, associating the phone ringing with someone knocking on the door and saying "come in" as a response would represent a type of associative activation error. Associative activation errors are also considered accidental slips of the tongue.

Loss of activation is the error of executing an action but forgetting the goal behind the intended action.^[11] A common example of a loss of activation error is walking into a room and forgetting the purpose for walking into the room.

Lastly, mode errors occur when the input for an action is the same for different modes of operation, but the output of that action varies according to the selected mode.^[11] These errors could easily occur with the gear shift control in cars, since the action of stepping on the gas pedal to execute the action is the same for all gears, but the direction in which the car moves depends on the selected gear. This could lead to detrimental consequences if a user was accidentally in reverse mode but intended to be in drive mode.