Covert hypnosis

Covert hypnosis is an attempt to communicate with another person's unconscious mind without informing the subject that they will be hypnotized. It is also known as conversational hypnosis or sleight of mouth. (although both Conversational Hypnosis and Slight of Mouth can also be done overtly). It is a term largely used by proponents of neuro-linguistic programming (NLP), a pseudoscientific approach to communication and interaction.

The objective is to change the person's behavior subconsciously so that the target believes that they changed their mind of their own volition. When or if performed successfully, the target is unaware that they were hypnotized or that anything unusual has occurred. Arguably there is a debate about what hypnosis is, and how covert hypnosis should be classified. "Standard" hypnosis requires the focus and attention of the subject, while covert hypnosis seems to focus on "softening" the subject by using confusion, fatigue, directed attention, and interrupted sentences. This is most similar to salesmen talking to customers when they are tired. Critical thinking and questioning of statements likely requires mental effort. The theme of "covert hypnosis" appears to be along the lines of causing the subject to enter "down time". Regardless of if "covert hypnosis" is "hypnosis" by a standard definition, fatigue does appear to make critically thinking more difficult. This might explain why interrogation, military training, and cult-recruitment practices prefer to deprive their new recruits of sleep.