Stop inviting unnecessary people at meetings to stop wasting time — common knowledge, right? Well, apparently there's a magic number to how many people you should have: seven, according to the book Decide & Deliver: 5 Steps to Breakthrough Performance in Your Organization.
In a study, the authors found that once you've got seven people in a decision-making group, each additional member reduces decision effectiveness by 10 per cent. Thus, a group of 17 or more rarely makes any decisions. Based on her experience, business coach Kate Purmal agrees:
This resonates with me, and is a predictor of positive "group dynamic" as well. I coach executives, both individually and in groups. Groups smaller than 6 seem to lack the breadth of ideas and collaboration. On the other hand, groups larger than 8 become unwieldy, and there is not enough time or focus for each individual to contribute effectively.
As CBS notes, larger groups can make decisions if they adopt a strict set of policies, but drawing up those policies is a lot of work in the first place. So the next time you're calling a meeting, try and keep it to seven people.