Influence made The Harvard Business Review 2009 List of breakthrough business ideas.

As you know, I’m a fan of the idea that social media may expand traditional spheres of influence by eroding reliance on physical “nearness” (propinquity), to decision-makers.

The HBR study by James Fowler and Nicholas A. Christakis tightens the noose the other way:

“New research shows that personal influence is a short-range phenomenon, dissipating entirely at three degrees of remove from the person who exercises it. This has implications for business, where the success of campaigns to foster, say, creativity or worker safety may hinge on enlisting employees to influence colleagues’ behavior.”

That means we influence only a very small sphere of people in our personal lives.

On the up side, it does support our Influencer50 ethos: conduct quality research into bona fide influencers, understand their networks, and work with them directly.

Hat tip to Leili McKinley.