I am writing this during a chess tournament for kids and I just talked to a mother, which triggered this post.
When her son made a mistake which resulted in loss of his queen and as a result loss of the game she said:
"I better don't talk to him. I'd only scold him for his mistakes."
My immediate answer was:
"Of course you should talk to your son! You should praise him for the way he played."
This resulted in a blank stare.
Is this really so difficult to understand? When somebody makes a mistake, most of the time, they know very well they made a mistake. The chess playing kid knows he lost. He knows losing the queen wasn't a smart idea. Often kids know this so well that they start crying. Trust me on this: There is no need to tell them what they did wrong. They'll focus their thoughts on the things they did wrong. And this doesn't help.
Instead tell them what the did well. A kid playing a game of chess most certainly made a couple of good moves. Your task is to find these moves. Or maybe he remembered to press the clock most of the time after his move. Or he used the available time well to think carefully. Or he remembered to shake hands and setup the board again after the game.
Praise him for that.
It will move the focus to the things he did well. It will turn his focus in something positive. It will motivate him to continue playing and learning. And sooner or later he will start taking care of his queen as well.
And the same applies when you are coaching grown ups. A software developer who introduced a bug knows he made a mistake. And he doesn't enjoys it. Especially when it was a very damaging bug. chastening him doesn't help. Instead find the thing he does well. Does a different module of him work well? Did he fix the bug quickly? Does he help his coworkers? Is he especially knowledgeable about a certain area? Did he improve some skills in the past months? Praise him for that.
You might think "But I can't praise the people that make mistakes! That's unfair". You are wrong. You can. You should. You MUST. But of course you should praise the ones doing good work as well. The difference is: Praising the good is much easier and requires much less skill on your side. So if you have problems with praising, you might start with the good ones today.