Prototypically, hypnosis involves a social interaction between 2 people, one assuming the role of the hypnotist and the other taking on the role of the hypnotic subject. To this interaction, both parties bring their pre-existing interpersonal styles, as well as any strategies and attitudes they may associate with the 2 different roles. In addition, as the interaction unfolds, the parties' behaviors may exert influences in both directions, and may become entrained-that is, synchronized, coordinated, and mutually supportive or antagonistic-in important ways. In this article, our goals are to review theory, clinical and other observations, and research on these interpersonal aspects of hypnosis, to address their possible importance for and relation to various other key phenomena that occur in hypnosis, and to suggest some frameworks for future conceptualization and research.