Brainstorming has been around a long time. It's attributed to Alex Osborn in the late 1950's. He stated (without empirical evidence to back up his claim) that people produce twice as many ideas when working in a group than working alone. And such was his influence, the concept of brainstorming was born and its use has been prolific ever since.
However, just because something is so widespread doesn't mean that it holds up to scientific scrutiny. Quoting from Adrian Furnham's The Brainstorming Myth , "Research shows unequivocally the brainstorming groups produces fewer and poor quality ideas as the same number of individuals working alone."
His report in Business Strategy Review, 2000 sites several reasons for brainstorming's failures as an effective technique. They are: 1, social loafing; 2, evaluation apprehension; and 3, production blocking.
What are each of these about? Social loafing occurs when, in a group, individuals make less effort relying on others for ideas. Evaluation apprehension is what it basically says: you make the judgement that people will ridicule your ideas were you to share them and so you don't share them. Finally, production blocking is the concept that only one person can share an idea at any one time slowing down the whole process.
Brainstorming then is an unsuccessful model when delivered in the way that it so frequently is presented. It needs an overhaul. Fortunately, the overhaul is a lot easier than one might think. The solution is to combine the power of individual thought but to then bring those ideas 'to the table'. That way creative thinking isn't stifled by 'blocking' but shared ownership remains possible through the sharing of ideas.
It's strange how brainstorming has remained so popular despite the psychology, and indeed Business Strategy Review, questioning its effectiveness. Clearly, habits are hard to break no matter where they occur.