Running head : INTERPERSONAL DISTANCE IN VIRTUAL ENVIRONMENTS Interpersonal Distance in Immersive Virtual Environments

Digital immersive virtual environment technology (IVET) enables behavioral scientists to conduct ecologically realistic experiments with near perfect experimental control. We employed IVET to study the interpersonal distance maintained between participants and virtual humans. In study one, participants traversed a three-dimensional virtual room in which a virtual human stood. In study two, a virtual human approached participants. In both studies, participant gender, virtual human gender, virtual human gaze behavior, and whether or not virtual humans were allegedly controlled by humans (i.e., avatars) or computers (i.e., agents) were varied. Results indicated that participants maintained greater distance from virtual humans when approaching their fronts compared to their backs. In addition, participants gave more personal space to virtual agents who engaged them in mutual gaze. Moreover, when virtual humans invaded their personal space, participants moved farthest from virtual human agents. The advantages and disadvantages of IVET for the study of human behavior are discussed. Interpersonal Distance in IVEs 3 Interpersonal Distance in Immersive Virtual Environments In Neuromancer (1984), William Gibson described virtual reality as a ‘consensual hallucination,’ a place where one intentionally uses technology to replace sensory input from the physical world, hoodwinking the five senses with synthetic stimuli. In Gibson’s work, digital virtual humans were largely indistinguishable from physical (i.e., “flesh and blood”) humans. Although Gibson wrote more than a decade ago about immersive virtual environments as science fiction, today social psychologists and others have begun to examine social interaction involving virtual humans (i.e., three-dimensional digital human representations that look and act in many ways like people) scientifically. We began our own such work by examining proxemics, the study of interpersonal distance. As we enter a new millennium, digital technology has raised opportunities as well as new issues for proxemics research. Digital representations of human beings are becoming common in communication media and entertainment, particularly in immersive virtual environments (IVEs). Digital IVEs are now utilized for communication (Slater, Sadagic, Usoh, & Schroeder, 2000; Guye-Vuilleme, et al., 1999; Biocca & Levy, 1995) particularly in the business world (DeFanti, 2000). Psychologists have begun to use IVET, incorporating digital representations of humans as a tool to study human behavior to maximize ecological realism without sacrificing experimental control (Blascovich, et al., in press). IVET provides a unique and valuable tool for proxemics researches. Past proxemics studies have typically employed observational methods with little or no experimental control, confederates who may behave inconsistently, and projective measurement techniques. In contrast, IVET allows investigators to maintain complete control over virtual human Interpersonal Distance in IVEs 4 representations’ appearance, behavior, and environment, while ensuring a high degree of ecological validity or mundane realism (Blascovich, 2001; Loomis, Beall, & Blascovich, 1999). In addition, because specification of the exact location and orientation of the participant is a key and necessary technological aspect of IVET, proxemic behavior can be measured accurately online, continuously and covertly. Furthermore, using IVET, researchers can ensure that participants’ eye height is matched with eye height of others in the IVEs, improving the salience of gaze manipulations and controlling for status differences due to height. Consequently, researchers have begun to use virtual environments as a tool to investigate personal space (Sommer, 2002; Bailenson, Blascovich, Beall, & Loomis, 2001; Bailenson, Beall, Blascovich, Weisbuch, & Raimundo, 2001; Krikorian, Lee, Chock, & Harms, 2000; Reeves & Nass, 1996). In a previous study (Bailenson et al., 2001), we demonstrated nonverbal compensation effects (Argyle & Dean, 1965; Burgoon, Stern, & Dillman, 1995; Patterson & Webb, 2002) in an experiment in which participants interacted with virtual humans. Compensation in nonverbal behavior typically occurs when people use different types of gestures to maintain and regulate an appropriate level of interpersonal immediacy (Mehrabian, 1967). For example, people increase their interpersonal distance from interactants who engage them in mutual gaze. In our previous study, participants walked up to virtual humans ostensibly to memorize certain features of their clothes. We manipulated the degree of mutual gaze exhibited by the virtual humans and continuously measured the distance between participants and the virtual humans. Our results demonstrated that, proxemically, in some ways participants treated virtual agents as if they were actual humans. Participants rarely violated a personal space bubble of 40 cm and furthermore approached more closely to the back compared to the front of virtual people. Moreover, we demonstrated compensation effects in IVEs—participants maintained a greater Interpersonal Distance in IVEs 5 distance from virtual humans who maintained constant mutual gaze than from virtual humans that did not. However, this first study left some cruc ial questions unanswered, as only virtual humans that were actually and perceived to be computer-controlled and served as the interactants. Blascovich and colleagues’ threshold model of social influence within virtual environments (Blascovich, in press; Blascovich, 2001; Blascovich et al., in press) specifies the behavioral impact of two types of virtual humans, embodied agents and avatars. Preset computer algorithms completely control the former, and another human being controls the latter online. According to Blascovich et al.’s model, at any given level of realism (conglomeration of social, behavioral, anthropometric, and photographic realism), a lower social influence threshold exists for avatars than for agents on deliberate, high level (e.g., conscious or controlled) responses, but relatively equal social influence exists on automatic, low-level (e.g., unconscious, uncontrolled) responses (see Figure 1). In other words, holding all sensory information constant, knowledge that a human controls a representation (i.e., avatar) will result in greater social influence than a comparable representation controlled by a computer program (i.e., agent) for highlevel but not low-level responses. Hence, for highlevel responses (e.g. meaningful conversations) the slope of the social influence threshold is relatively steep, but for low-level responses (e.g., reflexes, less consciously controlled processes) the slope of the threshold is relatively shallow (see Figure 1). It can be argued that proxemics involves a fairly automatic, low-level form of social influence, such that it is regulated without regard to conscious beliefs about the agency of a virtual person (Gifford, 1996). Agency beliefs should have a noticeable effect on the use of more conscious, highlevel nonverbal compensation. In certain situations, people compensate for inappropriate increases in Interpersonal Distance in IVEs 6 intimacy or immediacy (Burgoon, Stern, & Dillman, 1995). In other words, if Person A uses signals such as interpersonal distance, gaze, gait, or facial expression to indicate an increase in immediacy towards Person B, then person B should compensate by decreasing immediacy using a similar type of signal. On the other hand, if the increase in immediacy is appropriate, then reciprocity could occur, such that Person B will mimic Person A’s increase in immediacy. Usually this reciprocation of immediacy occurs when Person B wants to confirm closeness in a relationship (Manusov, 1995). However, previous research on immediacy and gesture has demonstrated mixed results, sometimes finding compensation, other times finding reciprocity (Andersen, Guerrero, Buller, & Jorgensen, 1998; Hale & Burgoon, 1984). In the current set of studies, we expected to find more reciprocity with avatars than with agents, because it is doubtful that participants would seek to form close relationships (i.e., increase immediacy) with an embodied computer algorithm. Our previous study utilized only male agents. In that study, we found an interaction between the gender of participants and the agents’ gaze behavior such that female participants regulated their personal space as a function of the agents’ gaze behavior more than did male participants. In the current studies, we utilized both male and female virtual humans to further investigate that gender difference. Overview of Experiments. We immersed participants in a single virtual environment containing a virtual human. In both studies reported in this paper, we varied the same virtual human characteristics: gender, agency (agent vs. avatar; i.e., whether they were apparently controlled by a computer or by another human), and gaze behavior (mutual gaze or not). We measured participants’ behaviors including interpersonal distance, memory, and selfreported social presence and affect ratings. Interpersonal Distance in IVEs 7 In Experiment 1, participants were asked to memorize labels on virtual humans’ shirts. As participants walked about the virtual environment, we tracked their position and orientation unobtrusively and automatically. Our hypotheses stem from research on compensation effects discussed above as well as our theoretical model (Blascovich, in press; Blascovich, 2001; Blascovich et al., in press). We hypothesized that participants would leave a larger personal space bubble around virtual humans who maintained eye gaze with the participants than around virtual humans who did not. In addition, in line with Blascovich et al.’s arguments regarding social influence, we predicted that participants would maintain more space around agents who engaged them in mutual gaze than agents who did not, but