Social information processing theory offers a testable set of theoretical mechanisms regarding how and why individuals are able to engage in interpersonal communication in lean online environments that lack most nonverbal cues. The theory was developed in response to early scholarly claims that the relative absence of cues in computer-mediated interaction created an inherently problematic environment for impression formation and relationship development. The theory identifies sender, receiver, message, and feedback dynamics under which communicators may achieve outcomes that are less than or comparable to those achieved through face-to-face interaction. The hyperpersonal perspective, a special case of social information processing theory, extends the dynamics to explain the circumstances under which communicators may achieve outcomes that exceed those of their face-to-face counterparts. This entry describes the emergence of the perspective, theoretical approaches used in its study, and empirical findings resulting from its investigation.