Reading · Laws of Software Engineering

2 min read

Individual productivity decreases as group size increases.

Takeaways

In large teams, some people put in less effort because they assume others will pick up the slack or because their contributions are less visible.
More people mean more communication, meetings, and alignment needed. Time spent coordinating increases, leaving less time for actual work.
There is a point at which adding people yields diminishing returns, or even negative returns per person. Small, focused teams often outperform poorly coordinated larger teams.
Smaller teams or individuals feel greater ownership and responsibility.

Overview

The Ringelmann Effect states that as more people work together, individual effort decreases. In software teams, productivity per person often declines in larger groups due to coordination overhead and some individuals contributing less when in a crowd.

This effect warns that adding team members can make each existing member less efficient. Along with Brooks’s Law, it shows that teamwork doesn’t scale linearly. Teams must be structured to mitigate this with clear roles and small, focused groups.

The Ringelmann Effect

Examples

In a brainstorming session with 3 people, each might contribute many ideas. In a session with 15 people, many participants will say nothing, assuming others will speak.

If 10 developers work on one module, merging code, resolving conflicts, and communicating design decisions can consume significant time. This effect motivates Amazon’s “Two Pizza Rule” (a team feedable by two pizzas, roughly 5-8 people).

Origins

Named after Max Ringelmann, a French agricultural engineer who observed it in physical tasks around 1913. He found that when people pulled on a rope together, each individual exerted less force than when pulling alone.

The phenomenon was later termed “social loafing” in psychology. It has been demonstrated in many group situations beyond rope pulling, from cognitive tasks to workplace productivity.