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Anthon, thanks for bringing the article to our attention.
http://www.economist.com/science/displayStory.cfm?story_id=13176775&fsrc=nwlptwfree<about:blank>

I've used the "Dunbar Number" since it's publication in developing many of my social dynamics models. I believe the Dumber Number can only be realistically applied to groups that at least occasionally meet face-to-face. That is because face-to-face interactions also bring into play hormonal and neurological changes in people involved which are minimized/excludes in virtual relationships. 



The new field of "social neuroscience" in the past 5 years has made some groundbreaking discoveries (and continues to do so) about our neurological/chemical activities that take place in our face-to-face interactions as summarized below:



.       Hormones: oxytocin and vasopressin promote trust and bonding. 

.       Neurotransmitters: dopamine (enhances attention) and serotonin (reduces fear and worry). 

.       Mirror cells: reproduces other person's actions/emotions in our brains.

.       Spindle cells: instantly choose best response among many.

.       Oscillator cells: regulate how and when bodies move together. 



Cheers,

Charlie



Charles (Kalev) Ehin, Ph.D.
Emeritus Professor of Management
The Gore School of Business
Westminster College, Salt Lake City
[log in to unmask]<mailto:[log in to unmask]> 
www.UnManagement.com<http://www.unmanagement.com/>

  ----- Original Message ----- 
  From: E. Anthon Eff<mailto:[log in to unmask]> 
  To: [log in to unmask]<mailto:[log in to unmask]> 
  Sent: Thursday, February 26, 2009 11:02 AM
  Subject: [SOCNET] Facebook and Dunbar number


  *****  To join INSNA, visit http://www.insna.org<http://www.insna.org/>  *****

  Just-published short article in the Economist (free content) on size of 
  social networks:

  http://www.economist.com/science/displayStory.cfm?story_id=13176775&fsrc=nwlptwfree<http://www.economist.com/science/displayStory.cfm?story_id=13176775&fsrc=nwlptwfree>

  -- 
  E. Anthon Eff, Associate Professor
  Dept. of Economics, Middle Tennessee State University
  Box X050, Murfreesboro TN 37132
  Phone: 615.898.2387
  http://www.mtsu.edu/~eaeff/<http://www.mtsu.edu/~eaeff/>

  Natura non facit saltum.

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