The Ringelmann effect, the hidden tax on team size

In the 1880s a French agricultural engineer named Max Ringelmann attached a rope to a dynamometer and measured how hard men pulled. Alone, the average was about 85 kilograms of force. In a group of seven it dropped to 65 per man, and in a group of fourteen to 61. The reported figures put two-man teams at 93 percent of what those men produced individually, three-man teams at 85, and eight-man teams at 49. Every man was pulling. The group as a whole moved more weight. But the average man was quietly doing less.

Ringelmann assumed the cause was coordination, the lack of simultaneity in their efforts, arms and timing working against each other. For most of a century nobody checked. Then in 1974 Alan Ingham, George Levinger, James Graves and Vaughn Peckham rebuilt the experiment to separate the two possible causes. In one condition, people were blindfolded and confederates behind them faked the sound and motion of pulling, so the participant believed they were part of a team while pulling entirely alone. There was no coordination to lose, because there was nobody to coordinate with. Effort still fell.

Their replication corrected the shape of the original curve as well. The drop was steep going from one person to two, and from two to three. Adding a fourth, fifth or sixth produced no meaningful further decline. The tax is not linear. It is charged almost entirely in the first few names.

One caveat about the famous numbers themselves. The percentage table everyone quotes comes from Walther Moede's secondhand report in 1927. Ringelmann's original paper was not rediscovered until 1986, by Kravitz and Martin, who also established that he was French rather than German and that the work was done in the 1880s.

When my contribution is identifiable, I give what I have. When it dissolves into ours, something eases off, and the part worth sitting with is that it does not feel like slacking from the inside. Nobody in Ringelmann's rope line decided to pull less.

Now put that next to how work is actually assigned. Six owners of a task is a precise way of saying nobody owns it. The question that does the work is asked of every deliverable and takes one word to answer: who owns this, singular. If your project list has a column of names where the owner should be, the tax is already being paid, and because the curve is steepest at the start, it is being paid mostly by the second and third name rather than the tenth.

The effect also has conditions where it weakens or vanishes, which is the useful half. It shrinks when individual contributions are visible and measured, when the task is one people find meaningful, when the group is small and cohesive, and when people expect their own effort to matter to the outcome. Karau and Williams established this across 78 studies in 1993. So the lever is not smaller teams for their own sake, it is making one person's contribution legible.

Source: Ringelmann's experiments, conducted in the 1880s and published in 1913. The replication that separated coordination loss from motivation loss is Ingham, Levinger, Graves and Peckham, The Ringelmann Effect: Studies of Group Size and Group Performance, Journal of Experimental Social Psychology, 1974. The moderators come from Karau and Williams, 1993, a meta-analysis of 78 studies.

Leading Teams

J. Richard Hackman, 2002

On the conditions that make a team work, from the researcher who spent a career finding out that the design of the team matters more than the talent in it. The chapter on size is the one that speaks to this entry.