The executive assistant was listening to her CEO complain about how hard it was to get a strategic message to everybody. “Actually,” replied the assistant, “I could get a message to the entire company in no time at all by spreading a rumor through the grapevine.”

She knew something about communication that her boss didn’t.

Research suggests that up to 70% of all organization communication comes through the grapevine, yet many senior leaders are unaware that it exists or how it operates. One study, in fact, found that while 92% of lower-level managers realized the grapevine was active, only 70% of upper-level managers knew about it. In the same study, 88% of supervisors said they understood that the absence of formal communication increased activity through informal channels – but only 54% of executives understood this correlation.

The grapevine – Webster’s “informal person-to-person means of circulating information or gossip” – is the informal and unsanctioned communication network found in every organization. From my interviews with over 1100 employees in a wide variety of companies and industries, I learned a lot about the power of the grapevine.

I learned, for example, that if there were conflicting messages — one delivered during a speech from the company leader and another spread through the grapevine — more people (47%) would believe the grapevine, and only 42% would believe senior leadership. (The remaining 11% were undecided.)

Read the rest here: http://www.forbes.com/sites/carolkinseygoman/2013/11/30/what-leaders-dont-know-about-the-rumor-mill/