At last, I have found evidence that pessimists have an integral role to play in a high performing team!! 

My interest in this is due to being a Pessimist. I actually prefer to be seen as a Realist but society unfortunately sees me and other Pessimists differently!!

It is great to be surrounded by Optimists but the reality for me has been the avoidance of bad things that we know are likely to happen but don't want to acknowledge them because being Pessimistic is not viewed well. I have been in so many situations during my career when I have seen failure approaching and if accepted it can be avoided with a Plan B, however, the Optimists refuse to admit the impending doom and prefer to deal with it when it arrives. The situation is then more harmful and takes longer to turn around.

The article proves to me that high performing teams need a sprinkle of everything as if they cannot sustain success if they all have the same view on life and input into the team.