Dunbar’s Number. Should A Sales Rep Care?


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According to British anthropologist Robin Dunbar, 150 is the “cognitive limit to the number of individuals with whom any one person can maintain stable relationships.” Simply put, you can’t have more than 150 friends and business associates. Establishing that 151st contact causes a weakening of some other relationship.

Obviously, it’s not quite that cut and dried. Some of us can handle more contacts, others of us fewer, but on average Professor Dunbar’s number holds up under scientific scrutiny. Hunter-gatherer societies tended to grow to about 150 members, and then split into two groups. Neolithic farming villages typically had 150 residents. 150 was the basic unit size for armies in the Roman Empire and still holds true for military units today. British counties in the 18th century, apparently with only one exception, had populations of around 150. Listen to Professor Dunbar himself. The examples go on and on.

So, Mr. or Ms. Sales Rep, how many stable business relationships do you have? How many should you have? How many can you effectively handle? We all know how vital they are to our success.

My company, The YPS Group has north of 3,200 subscribers to our Ideas! e-newsletter. I personally have 2,737 contacts in Outlook. I have 248 direct LinkedIn connections, 32,400 2nd degree and 2,534,700 3rd degree connections.

Frankly, I have no earthly idea how many strong business relationships I actually have or can effectively manage.

Does my sales rep DNA enable me to far exceed the average 150? Yes. Does my career-long habit of maintaining contact information help me far exceed 150? Yes. (In retrospect, I wish I had kept my box of 3X5 cards after transferring it to my IBM PC with 16K of memory back in ’84.) Does my regular use of LinkedIn’s capabilities help me far exceed 150? Yes. Does my blog – especially the video posts – help me far exceed 150? Yes. YES. YES!!!

That last one’s different. And the difference is, in my humble opinion HUGE. My blog makes it easier for other people to maintain a relationship with me. “They” do the work, I get the relationship-building benefit. Watch this for an example.

Well look, I already admitted I don’t know how many business relationships I’m capable of effectively maintaining. I can guarantee you though, that I’ll be pounding hard on my blog, on LinkedIn and on Twitter to get as far above 150 as I can. What are you doing?

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Republished with author's permission from original post.

Todd Youngblood
Todd Youngblood is passionate about sales productivity. His 3+ year career in Executive Management, Sales, Marketing and Consulting has focused on selling more, better, cheaper and faster. He established The YPS Group, Inc. in 1999 based on his years of experience in Sales Process Engineering – that is, combining creativity and discipline in the design, implementation and use of work processes for highly effective sales teams.


  1. Todd, I’ve got 2K contacts in outlook, Twitter followers, 100K email subscribers etc. etc. I don’t think is what Dunbar had in mind when he said “stable” relationships.

    These days it’s easy to acquire subscribers/friends/contacts/followers. But building a relationship requires some interaction, an investment of time on both parties.

    Maybe it’s a bit easier now with social media tools to stay in touch, but I’m skeptical that will mean a real/stable relationship with thousands of people.

  2. I agree with Bob’s point. While your blog is great and you have a broader reach than you would have without it but that is what TV, News Paper and other media did in the past. It isn’t a *stable* relationship.

    Yet – you are on to something. My current number is 1500 stable relationships. Is my neo cortex so much better – not at all. It is actually at the very best just average. But here is how I deal with the Dunbar number:
    I trust that we indeed have that limit of more or less 150 social connections.
    I also trust that we are on average able to lift no more than our own body weight.
    I also trust that the maximum speed we can run is sub 25 miles/hour
    I trust we can not fly and we can’t dive for more than a few minutes.

    But all the above didn’t stop us to create ways to overcome those physical limits. And as you can read on my personal website – we are just about to create tools to overcome yet another physical limit: the social connectivity limitation.

    My 6,000 followers are no *stable connections* But about 1,500 I follow I have frequent connection with. I have 1,500 people in my Xeesm system as favorites out of about 8,000. I maintain 1,500 LinkedIn connection and consider most stable connections. This is all possible because I use a tool that helps me to do that. Indeed by Neo Cortex wouldn’t be capable to handle so many connections, like other parts of may brain wouldn’t be able to compute a predictive model based forecast – but I do understand all the implication and the computational model of said forecast.

    In other words: Dunbar’s number is VERY relevant – because it gives us an indicator how good our new tools are that help us overcome our physical limitations.

    If you have a chance to join the Social Selling Webinar tomorrow morning, we will actually talk about just that.



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