Tony Buzan's classic Use Both Sides of Your Brain has gone thru three editions since 1976 and is still considered by many to be foundational in the area of brain science. His step-by-step exercises for discovering the powers of the right and left sides of the brain and learning to use them more effectively have been a source of inspiration and insight for millions.
Two recent articles, one in FastCompany; 4 Tips to Master Thinking with Both Side of Your Brain and Boot Creativity and the other from the National Institutes of Heath; The Neural Basis of Optimism and Pessimism, offer further insights on the inner workings and wiring of the brain and the interplay between Cognitive Bias and Creativity.
FastCo; "The right side of the brain remembers the big picture, the left side of the brain recalls the details. Complex cognitive functions require the brain regions to work in integrated fashion, shifting between divergent and convergent thinking to combine new information with old and even forgotten knowledge... the more easily you shift between both sides, the more complex a creative a thinker you can be."
NIH; "Like all other human experiences, the basic mental attitudes of optimism and pessimism are closely interlinked with distinct physiological processes. Pessimistic views are generally mediated by the right-hemisphere (RH), whereas optimistic attitudes are mediated primarily by the left-hemisphere (LH)."
If the right side of the brain remembers the big picture and is more pessimistic and the left side recalls the details and is more optimistic, what does this tell us about how to creatively problem solve?
It appears that when we're in the details we're more optimistic and when we're looking at the future we're more pessimistic. What is the difference? The perceived degree of ambiguity. This also offers some insights in to why "analysts" may be more risk averse and pessimistic and "synthesists" more optimistic and tolerant of ambiguity.
Awareness of this element is critical when using or facilitating Design Thinking's problem solving process. If the composition of the team makes it highly risk averse (analytical and intolerant of ambiguity) or short term focused (impatient) it will be difficult for the them to generate ideas that are very different and diverse. At the same time, if the team is heavily loaded with out-of-the-box thinkers it could be a challenge to converge on a viable solution.
This isn't to say that all you want on the team are Dreamstormers. In order to narrow down to an executable solution which is also viable, deep critical consideration of weaknesses and potential failure points has to occur somewhere in the design process. That should happen after the dreamstorming is over and the ideas have been captured and organized, but it has to happen if you are going to achieve any useful success.
This idea is reminiscent of Disney's Three Rooms and the associated roles of Dreamer, Realist and Critic. Leave any one of them out of the process and there is a much greater chance of having missed something important to the success of the project.