Team effectiveness is disproportionately influenced by your group’s best performer or "extra-miler"

The quality of a team’s best performer
(the “extra miler”) is diagnostic of
the group’s overall effectiveness.

In The Hobbit, fifteen companions come together on a quest for a dragon’s treasure. Traditional team analysis would judge “Thorin and Company” on the sum of its parts: Ori is stalwart, and Dori strongly stalwart, and, ok, Bifur seems stalwart enough … a fairly stalwart team, then. But we’re beginning to understand that single individuals can have a disproportionate impact on group performance. A new paper from the University of Iowa demonstrates how extra milers put in remarkable efforts to make sure the team holds together.

The study looked at patterns of performance in a Chinese petrochemical company of 87 teams each of about seven members. Ning Li’s data showed teams performed better when they exhibited key processes, including: agreeing minimum working standards for the team, keeping tabs on progress to balance out members’ different workloads, and having extra help on hand when necessary. These team-level processes need to come from somewhere, so each team member rated their team-mates on qualities that might be useful: willingness to help, and expression of ideas and concerns (dubbed “voice”).

Team-member scores on helping and voice turned out to be good predictors of strong team processes … but here’s the thing: once you took into account the team’s stand-out helper, there was no value in looking at helpfulness of the other members; you already had your best guess at how constructive the team as a whole was likely to be. The same was true with voice: once you know where the strongest member stands, you can throw the other scores away. Li considers these maximally helpful individuals “extra-milers”, and when their extra is a mile, rather than just an inch, teams perform better.

Actually, it’s a little more complicated than that: there was one aspect of the other team members that mattered. This was how much their work thrust them into contact with the extra-miler in their team. Evidence suggests that minorities can influence behaviour in wider groups, but they need the opportunity to interact and model superior norms of behaviour. Accordingly, when the extra-miler was huddled away in the back room, their influence was minimal.

If you have a committed extra-miler well-embedded in a team, you don’t need to worry about measuring what everyone else is doing. What you do have to worry about is that the extra-miler has opportunities to interact with the team, spreading their positive way of doing things. In the case of Thorin and Company, success seemed to owe the presence of a headstrong hobbit willing to mix it up and act as a conscience. His inclusion was a wise wizardly choice. I mean, a solid managerial decision.


Li, N., Zhao, H., Walter, S., Zhang, X., & Yu, J. (2015). Achieving More With Less: Extra Milers’ Behavioral Influences in Teams. Journal of Applied Psychology DOI: 10.1037/apl0000010

–further reading–
Why your team should appoint a “meta-knowledge” champion – one person who’s aware of everyone else’s area of expertise

Post written by Alex Fradera (@alexfradera) for the BPS Research Digest.

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