I was introduced to “brainstorming” when I worked as a copywriter many years ago. Most ad agencies consider it an essential tactic for creating new campaigns.

In the advertising world, brainstorming involves a copywriter and an art director sitting together in a room, where they lob headlines and images at each other in search of the perfect ad. When the job is especially important—say, you’re competing against other agencies to land a new account—brainstorming sessions can involve lots of people and the action can become frenzied. Words fly around the room and doodles by the score are tacked on the walls until a consensus is reached on which ideas should live and which should die.

This is a bad scene for me. When I interact with peers at close range, my creative juices are not stirred—they become a stagnant pool. Everything my partners say is static. The storm part interferes with the brain part, preventing a clear train of thought.

I also discovered that I tend to be too polite to my colleagues. It was hard for me to discount ideas that I thought were completely bogus because I was afraid of hurting the art director’s feelings. I would say things like “Hmm…that’s interesting” or “Yes, that’s worth thinking about” as I stared longingly at the wastebasket, where I thought those ideas belonged.

Eventually I figured out that my problem isn’t poor creative skills; it’s my introvert nature. I’m also a bit of a daydreamer, which is a solitary enterprise. So I developed a new strategy for creative exploration. Prior to a brainstorming meeting, I would think about the project and try to come up with ideas on my own that I could then share when we got together. Putting my brain in solitary confinement was just what I needed; the headlines came fast and furiously. Interestingly, I found that traffic noise or other disturbances not involving human interaction did not deter my creative pursuits. Ideas surfaced as I rode the subway or walked through teeming crowds on the sidewalk. So I made sure I was ready to capture any thoughts worth preserving, always carrying a notebook and pen in my pocket while on foot or a tape recorder in the car.

The Truth About Brainstorming: Quantity Does Not Equal Quality

Although brainstorming was counterproductive for me, I assumed that it was the right venue for more social types. Since about two out of three people in the U.S. are extroverts, that should mean that most people love throwing ideas at each other in big groups. But I’ve had qualms about many standard practices at companies I’ve worked for over the years, so I began questioning this one as well and started doing some research.

A key trigger in making brainstorming popular was Alex Osborn, a partner in the top ad agency Batten, Barton, Durstine & Osborn (known as BBDO). Back in the 1940s, Osborn claimed that organizing groups of people to work together on one advertising project greatly accelerated creative output. He cited an example where ten employees working together at his agency came up with 87 ideas for a new drugstore in just 90 minutes. Osborn showcased these findings in his book Your Creative Power in a chapter entitled “How to Organize a Squad to Create Ideas.”

But this was hardly a controlled study. In subsequent years, the effectiveness of brainstorming has been put to more rigorous tests. Yale University researchers in 1958 assigned a series of creative puzzles to 12 four-person student teams, as well as 48 students working alone. The solo students dramatically outperformed the groups. They came up with not only more ideas but ones of better overall quality (more feasible, more effective). Marvin Dunnette, a psychology professor at the University of Minnesota, reported a similar edge for the solitary thinkers in a 1963 study. Other research since then has further tarnished brainstorming’s reputation.

Of course, some factors relevant to group performance may not have been considered in these studies. Brainstormers typically have a leader, and some leaders are more motivating and/or supportive than others. The nature of individuals assigned to a creative task can also vary widely. One group may dramatically outperform another depending on these factors. What appears important to remember is that brainstorming should not always be considered superior to individual work.

Why a Group May Underachieve

There are a number of reasons why the group dynamic may not be as successful as individuals working alone. Some of them are spelled out by Susan Cain in her bestselling book, Quiet: The Power of Introverts in a World That Can’t Stop Talking. While Cain’s main focus is the unsung strengths of introverts, she also addresses why the “forced collaboration” of brainstorming can have a negative impact on independent thought. She cites three factors in particular:

1. Social loafing. Some people shift into neutral in group settings, letting others do the creative work. Fewer ideas are likely to come from them.
2. Production blocking. Only one person can talk about an idea at one time in a group, which forces others into downtime as they sit and wait to have the floor.
3. Evaluation apprehension. A fear of expressing an idea that’s an embarrassing dud causes some people to hold back from contributing.

Cain also reports on psychologist Solomon Asch’s insights on group influence in the 1950s. Asch organized groups of student volunteers to take a simple visual test. In some of the groups, he planted actors who were told to give wrong answers confidently. The effect was dramatic. In the groups with no actors, only 5% of the students answered all questions incorrectly. In those with the actors, 75% of the students agreed with the wrong answers.

Brain Imaging Reveals Cognitive Shift During Group Activity

In more current times, advanced imaging has given us a look at what happens in our heads during brainstorming. People working in groups have less brain activity in areas of the frontal cortex associated with conscious decision making and more activity in areas associated with perception. This shift can make people less likely to think up new ideas and more likely to go along with what they’ve heard from others.

All these findings are reasons for introverts like me to celebrate. Of course, I could have confirmed my own suspicions about brainstorming by simply remembering one of our time-honored clichés: Too many cooks spoil the broth.