Abstract
An innovative technique was used to explore spatial cues utilized by participants in deciding to invade the group space of two strangers. Confederates were placed at varying intervals from the center line in four long hallways of varying widths, representing the four experimental conditions. Participants were tallied as they chose to walk between or around the confederates. The smallest critical distance, at which 100% of the participants chose to invade rather than avoid the space between the confederates, was established. A consistent ratio was found between the confederate to wall (external distance) and confederate to confederate (internal distance) for the first 100% invasion for each experimental distance. The authors suggest that some consistent proportionate distance may be fundamental to the participants' decisions to invade group space. Further research is suggested to investigate the concept of “response cost” when the participant is forced to alter his path to avoid invasion.