Ideal scrum team size, 5 to 7 +/- 2; why?

Free-Rider Problem? Ringelmann Effect

In 1913, Max Ringelmann, a French agricultural engineer, conducted what many believe was the first recorded social psychology experiment.

He carefully measured how much force people exerted when they pulled a rope alone, and when they pulled it with up to thirteen additional people.

He conducted additional studies in the lab and in the field and summarized all these results together.

His results were mind-boggling.

Applying his findings back to the rope experiment, Ringelmann found that when a person was added to the rope, everyone pulled with less strength.

When two people were on the line, they each pulled with 93 percent of the force of a person working alone.

Three people each pulled with 85 percent of the force, and so on.

By the time eight people joined the rope, they were each pulling with half the force of a single person.

As a result, a team of eight pulled the rope with no more total force than a team of seven.

In a set of simple rope pulling experiments he discovered that, in what is now known as the Ringelmann Effect, people’s efforts quickly diminish as team size increases.

Eight people, he found, didn’t even pull as hard as four individuals. He rationalized the decay in effort by suggesting it was difficult for team members to coordinate effort, and left it at that.

The Ringelmann Effect is another name for the dreaded free-rider problem. Free riders are people who try to hide in a crowd and let others do the work.

A summary of seventy-eight free-rider experiments published in the Journal of Personality and Social Psychology validated Ringelmann’s finding—that increasing the size of a group causes a decrease in individual effort.

But the study went a step further and examined the structural elements of cultures that cause free-rider behavior.

According to Ringelmann (1913), groups fail to reach their full potential because various interpersonal processes detracts from the group’s overall proficiency.

Namely, two distinct processes have been identified as potential sources for the reduced productivity of groups: loss of motivation, and coordination problems.

Part of’s behavioral code is the “two-pizza rule”: if a project team can’t be fed by two pizzas, it’s too big.

The rule exemplifies Bezos’s belief that real work should be managed by the smallest teams possible.

It is also a perfect illustration of a hunting party.

Less is more for team !! No body can hide !


Chandan Lal Patary

The Agilist’s Guidebook-A Reference for Organizational Agile Transformation | Enterprise Agile Coach