You’re probably familiar with brainstorming.  There is a complicated problem to be solved, so you get together in a group and throw out ideas hoping to come up with a great idea.  The basic rules of brainstorming (as well as the word brainstorming itself) come from Alex Osborn’s work in the 1960s.  The idea is to try to come up with as many ideas as possible, to avoid criticizing ideas at first, and to say whatever you are thinking rather than focusing at first on whether the idea would work.

There has been a lot of research on brainstorming over the years, and it generally shows that groups are less effective than individuals.  That is, if you got a group of three people brainstorming, that group would come up with fewer ideas (and fewer good ideas) than if the people had worked alone.  This observation that groups are less effective than individuals is called productivity loss.

A potentially powerful aspect of brainstorming, though, is the process of combining ideas.  That is, after a set of ideas are generated, it may turn out that a combination of a few of the ideas is more effective than any of those individual ideas alone.  Are groups more effective than individuals when combining ideas?

This question was explored in a paper in the May, 2011 issue of the Journal of Experimental Social Psychology by Nicholas Kohn, Paul Paulus, and YunHee Choi. 

In one study, participants were university students.  They either worked in groups of three or they arrived at the lab as a group of three people, but worked alone.  Their job was to generate ideas that would improve their university.  Consistent with the previous observations of productivity loss, the groups came up with fewer ideas than the sets of three people working alone.

After an initial idea generation stage, the participants were shown all of the ideas generated by the group (or by the group of three individuals in a session) and were asked to combine the ideas.  At this stage, some of the people who worked in groups where asked to do the idea combination working alone.  Likewise, some of the people who worked alone when generating ideas worked in a group to combine the ideas.

There were a couple of interesting observations from this study.  People who had worked in a group were more likely to make combinations from ideas that they had generated themselves than people who worked alone.  That is, being in a group seemed to make people focus on their own ideas.  People who worked alone at first seemed more open to other people’s ideas.  That said, the people who generated ideas in a group generally came up with more useful ideas overall after the ideas were combined. 

Still, this study seems to suggest that groups do not really do that well compared to the same number of people working alone.  Is there any advantage to working in a group?

In a second study, Kohn, Paulus, and Choi gave people a list of ideas that were generated by other people.  This situation mirrors cases where a committee has to evaluate suggestions made by others. 

In this case, people either worked in a group of three or they worked alone.  They were asked to combine the ideas to come up with new suggestions.  In a clever manipulation, some groups were given ideas that were frequently generated as suggestions for improving the university.  Other groups were given the same number of ideas but the ideas were all ones that are given by only a few people when generating ideas to improve the university. 

The people working alone created combinations of ideas that were judged to be moderately novel and moderately feasible regardless of the kinds of ideas they were given to start with. 

The people working in groups, though, were particularly productive when given rare ideas.  The groups generated combinations that were much more novel and yet still quite feasible to implement when given rare ideas.   That is, groups seemed particularly well-suited to taking rare ideas and creating new and interesting combinations from them.

Ultimately, if you are in a situation where you have to generate ideas, it is generally better to start by having people work alone.  That makes the collection of people more productive and also more open to new ideas.

That said, it may also be useful to break idea generation and combination into two stages.  Have one group start by generating ideas to solve a problem.  Then, get a different group of people together to create combinations of those ideas.  Afterward, the entire group can get together to discuss the results.