Interact is a computer program that displays verbal descriptions of what people might do in a given situation, of how they might respond emotionally to events, and of how they might attribute qualities or new identities to themselves and other interactants in order to account for unexpected happenings.

Interact achieves its results by employing multivariate non-linear equations that describe how events create impressions, by implementing a cybernetic model that represents people as maintaining cultural meanings through their actions and interpretations. The  program utilizes large dictionaries that index cultural meanings. The program's predictions can be, and have been, tested in experimental and field studies, and results largely support the validity of Interact simulations.

Interact is first and foremost a research tool for examining the implications of Affect Control Theory. While the theory is simple - people try to have experiences that confirm their basic sentiments - detailed application of the theory is complicated by computations and data processing, and Interact is required to keep analyses from getting bogged down.