The hallmark of a really effective brainstorming is an abundance of genuine and heartfelt laughter. There’s a reason for this: laughter can help people solve problems that demand creative solutions, by making it easier to think more broadly and associate ideas/relationships more freely. This is scientifically validated by recent research that shows that people in a lighter mood experience more eureka! moments and greater inspiration.
Karuna Subramaniam, in research she did when she was with Northwestern University, found that boosting the mood of volunteers increased their likelihood of having an aha! moment as measured by their ability to solve a word association puzzle, the standard test for creative problem solving. Those who watched a comedy were measurably better at the task using insight than those who watched a horror film, or worse yet, a lecture about quantum electronics.