Ringelmann Effect

Definition

The Ringelmann effect refers to individuals expending less individual effort on a task when working as part of a group than when working alone.

Background and History

Max Ringelmann was a French agricultural engineer who was interested in examining various aspects related to agricultural efficiency. He was primarily interested in conditions under which draft animals such as horses and oxen—and men—are more or less efficient in their work performance. Ringelmann's research represents some of the earliest systematic social psychological research. Because he was also interested in the process by which animals and men could be more efficient, his research also represents some of the earliest known human factors research. Actually, the human factors aspect of his research represented the primary focus of his research, whereas comparisons of [Page 755]individual and group performance were only a secondary interest at the time of his original research.

In some of his preliminary research, Ringelmann had male participants pull horizontally on a rope for approximately 5 seconds. Participants pulled on a rope individually, in groups of 7, or in groups of 14. During this time, their maximum pulling effort was recorded via a dynamometer (a device that measures maximum force exerted). Those participants who pulled alone exerted a mean force of 85.3 kg per person. When participants pulled in 7and 14-person groups, the mean force exerted per person was 65.0 kg and 61.4 kg, respectively. Thus, as group size increased, the average force exerted per individual decreased. Ringelmann found similar results when participants were asked to push a crossbar connected to a two-wheeled cart. When participants pushed alone they exerted more force (170.8 kg), on average, than when they pushed together with another person (154.1 kg).

Some of Ringelmann's most cited findings involve examining relative group performance as a function of group size in groups ranging in size from one to eight participants. Similar to his research mentioned previously, individual effort decreased as a function of group size. For example, assuming that the total force exerted for one worker was 1.00, the force exerted for two through eight workers was 1.86, 2.55, 3.08, 3.50, 3.78, 3.92, and 3.92, respectively, indicating a curvilinear relation among group size and group performance. That is, as group size increased, the total force exerted for the group decreased but the difference between twoand three-person groups was greater than the difference between fourand five-person groups and the difference between sevenand eight-person groups was still smaller. Interestingly, Ringelmann did not clearly specify what types of tasks these data were based on. They may or may not come from research specific to rope pulling as is often assumed.

Ringelmann acknowledged two potential reasons underlying this decrement of individual performance when working in groups. The first was that the effect was caused by coordination losses. For example, two people pulling on a rope would be more coordinated in their pulling (more likely to be in sync in their pulling) than would a group of seven or eight people putting together. For Ringelmann, this was the most likely explanation. Nonetheless, he also acknowledged the fact that such an effect might be the result of decreased motivation. For example, with more people pulling on a rope, individuals may feel that the work of their coworkers will be enough to successfully accomplish the task at hand, thus individual effort decreases as the result. Others did not attempt to disentangle the mystery of the Ringelmann effect until nearly a century after Ringelmann's original work.

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