Daniel Kahneman says his book Thinking Fast and Slow is not prescriptive, but plenty of us are trying to figure out how to improve our decision making since we read the book. 

In this excellent interview, Kahneman is asked how companies can apply what he's learned. He says one of the most important things a company can do is 'protect the pessimists.' All us optimists know that pessimists do not help us get more done. They slow us down. Right. They slow us down and make us think twice!

FORA.tv: Q&A: Economist Daniel Kahneman, the Pioneer of Heuristics, 2012-Oct-14, Interview by Nathan Labenz from The Singularity Summit 2012

At about 12 minutes, he talks about protecting pessimists.