Public Release: 

Groups perform better than the best individuals at solving complex problems

Study shows that the collective efforts of groups may be useful in boosting problem-solving skills

American Psychological Association

Washington, DC - Groups of three, four, or five perform better on complex problem solving than the best of an equivalent number of individuals, says a new study appearing in the April issue of the Journal of Personality and Social Psychology, published by the American Psychological Association (APA). This finding may transfer to scientific research teams and classroom problem solving and offer new ways for students to study and improve academic performance, according to the study authors.

In this study 760 students from the University of Illinois at Urbana- Champaign solved two letters-to-numbers coding problems as individuals or as groups of two, three, four and five people. Previous research has shown that groups perform better than the average individual on a wide range of problems. However, this study tested the relationship between group size and performance as compared to that of an equivalent number of individuals by comparing the number of trials to solutions and answers given for complex problems. The groups of three, four, and five performed better than the best of an equivalent number of individuals on the letters-to-numbers problems.

"We found that groups of size three, four, and five outperformed the best individuals and attribute this performance to the ability of people to work together to generate and adopt correct responses, reject erroneous responses, and effectively process information," said lead author Patrick Laughlin, PhD., of the University of Illinois at Urbana-Champaign.

Moreover, groups of two performed at the same level as the best of two individuals, suggesting that this group size was too small to introduce the necessary dynamics for optimal problem-solving. However, since groups of three, four, and five were able to achieve the same results, the authors submit that groups of at least three are necessary and sufficient to perform better than the best of an equivalent number of individuals on complex problems that require understanding of verbal, quantitative, or logical conceptual systems. Understanding these systems are necessary skills for scientific research teams, and the finding that groups of three or more perform better than the best of the same number of individuals may indicate that scientific research teams perform better than their top member would perform alone.

"Problem solving groups may also be a useful method for students to use in school," said Laughlin. Further research is necessary to determine if cooperative groups perform better than the best individuals in academic settings with different age groups and for other forms of problem solving.


Article: "Groups Perform Better Than the Best Individuals on Letters-to-Numbers Problems: Effects of Group Size", Patrick Laughlin, Erin Hatch, Jonathan Silver, and Lee Boh, University of Illinois at Urbana Champaign; Journal of Personality and Social Psychology, Vol. 90, No. 4

Patrick Laughlin can be reached by phone at (217) 333-4296 or by email at

Full text of the article is available from the APA Public Affairs Office and at

The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world's largest association of psychologists. APA's membership includes more than 150,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting health, education and human welfare.

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