Social Loafing

Social Cognition & Behavior

Latané et alia (1979)

Do we put in measurably less effort in a task when we perform it as a group?


There is an old saying that “many hands make light the work”. However, it can have a double meaning. The common and intended message is that collaboration is more productive than independent work, for all the reasons explained by classic economic theories. Not only can collaborators join their forces, but Zajonc’s (1965) theory of facilitation predicts that people are aroused by the mere presence of others and are thus likely to work harder when together. Yet, another possible interpretation is that group members might actually “hide in the crowd” and decrease their individual efforts. This phenomenon, known as “social loafing”, was first studied by Ringelmann (1913) in the context of a rope-pulling exercise, where he found that participants put in less individual effort as group size increased from 1 (100%) to 3 (88%) and 7 (59%). According to  Latané et alia (1979), three different reasons can explain these surprising results, all of which derive from the fact that group work involves a “lessened contingency between input and outcome.”

  • Working independently, the outcome depends 100% on an individual’s effort. Working in a group of n members, the outcome only depends 100%/n on each of their contributions. As a consequence, group members might decide to “hide in the crowd”: their own input will have little effect on the total outcome, so they can simply sit back and profit from other people’s work. This phenomenon is known as the “free rider effect” and is even more likely when the group task is perceived as having to reach a certain minimal goal, rather than a maximum possible.
  • Alternatively, group members might feel “lost in the crowd”—not incentivized to do little as in the free-rider effect, but not motivated to do much either because of their low degree of control over the group outcome.
  • Finally, and especially if they think (objectively or not, based on various cognitive biases) that others are less skillful and/or less motivated than them, the “sucker effect”  might lead them to limit their effort so as  to not be taken advantage of. 
Participants & Procedures

48 male undergraduates from Ohio State University (Columbus, OH, USA).

In groups of 6, participants were led to a soundproof room and asked to seat in a semicircle. The study was presented to them as investigating the amount of noise that people make in social settings, for instance when cheering. The task was very simple: claping and screaming (“Rah!”) as loudly as possible for 5s. The two tasks were tested separately, each participant performing twice alone, 4 times in pairs, 4 times in groups of 4, 6 times in groups of 6, but never more than twice in a row. The order of the conditions was of course counterbalanced across subjects. Finally, a General Radio sound-level meter was used to measure the level of noise produced—or rather the amount of work involved in producing sound pressure, the unit of which is dynes/cm2


As can be seen in the graph above, the average amount of effort put in by participants decreased with the size of the group. In pairs, they only performed at 71% of their individual capacity. In groups of 4 and 6, the ratios decreased to 51% and 40% respectively. This suggests that group settings can have a demotivating influence on individual effort. As Latané et alia (1979) concluded, however, the cure to the “social disease” of social loafing “is not no collaboration, but finding ways to channel social forces so that the group can serve as a means of intensifying individual responsibility rather than diffusing it.” Potential strategies have been studied by Dawes et alia (1986).

IA Tip

In line with IB guidelines, we recommend that students only compare two conditions in their experiment and obtain a single measurable result for each participant in each condition. Doing otherwise would complicate inferential statistics without any benefit as far as the IA is concerned.

Here, students should only compare independent work and group work conditions. To obtain individual results, they could modify the experiment and use a different task, e.g., one that can be completed online. This is a great opportunity to test participants individually all while telling them that their results will or will not be combined with others in a group. Importantly, a replication of this study can meet all ethical requirements as it does not test group pressure but, to the contrary, individual defection.


Latané, B., Williams, K., & Harkins, S. (1979). Many hands make light the work: The causes and consequences of social loafing. Journal of Personality and Social Psychology, 37, 822–832.