The Allen curve was discovered by Massachusetts Institute of Technology Professor Thomas J. Allen in the late 1970s. It reveals the exponential drop of frequency of communication between engineers as the distance between them increases. [A related and highly significant finding of Allen was his identification of the key role for the key role for information gatekeepers. Often such interlocutors were poorly recognized by management and yet conveyed vital concepts from just the right people to just the right other people in the organization.]
During the late 1970s, Allen undertook a project to determine how the distance between engineers’ offices affects the frequency of technical communication between them. The result of that research, produced what is now known as the Allen Curve, revealed that there is a strong negative correlation between physical distance and the frequency of communication between work stations. The finding also revealed the critical distance of 50 meters for weekly technical communication.
This finding was originally documented in Allen’s book, Managing the Flow of Technology.
Recent development 
With the fast advancement of internet and sharp drop of telecommunication cost, some wonder the observation of Allen Curve in today's corporate environment. In his recently co-authored book, Allen examined this question and the same still holds true. He says
- "For example, rather than finding that the probability of telephone communication increases with distances, as face-to-face probability decays, our data show a decay in the use of all communication media with distance (following a near field rise)." [p. 58]
He further explains
- "We do not keep separate sets of people, some of which we communicate in one medium and some by another. The more often we see someone face-to-face, the more likely it is that we will telephone the person or communicate in some other medium." [p. 58]
In the business world, this principle has had a very strong influence in many areas, such as commercial architecture designs (See for example the Decker Engineering Building in New York, the Steelcase Corporate Development Center in Michigan, the BMW Research Center in Munich, and the Volkswagen assembly and delivery center in Dresden  ), and project management.
- Allen, Thomas J. (1984). Managing the Flow of Technology: Technology Transfer and the Dissemination of Technological Information Within the R&D Organization. Cambridge, MA: MIT Press.
- Allen, Thomas J.; G. Henn (2006). The Organization and Architecture of Innovation: Managing the Flow of Technology. Butterworth-Heinemann. p. 152.
- "Organizing for Innovative Product Development". Massachusetts Institute of Technology. Archived from the original on 2 April 2008. Retrieved 2008, 03, 25.
- "Architecture and Communication in Organizations". Massachusetts Institute of Technology. Retrieved 2008, 03, 25.
- "Management of Technology and Innovation". California Institute of Technology. Archived from the original on 18 April 2008. Retrieved 2008, 03, 25.
- Chen, Hsinchun. "Organizational Learning and Knowledge Generation". University of Arizona. Retrieved 2008, 03, 25.
- "Communication for Inspiration vs. Distance and Walls". Retrieved 2008, 03, 25.
- Henn, Gunter (03 2003). Transparent Factory Dresden: The Event of Assembling a Car (Paperback). Prestel. p. 64.
- Herbsleb, James; Mockus, Audris; Finholt, Thomas A.; Grinter, Rebecca E. (2001). "An Empirical Study of Global Software Development" (PDF). International Conference on Software Engineering. Retrieved 2008-03-25.
- Cleland, David L.; G. Henn (2006). Global Project Management Handbook: Planning, Organizing and Controlling International Projects, Second Edition. Roland Gareis. McGraw-Hill. p. 575.