I realize there's nothing more American than "healthy" competition. However, as a teacher of young children, I personally attest to the negative impact competition has on self-esteem, relationship-building, and overall emotional readiness in preschoolers. Please take a few minutes to read this fantastic article about competition and young children. It's a very quick read: The Cost of Competition.
I do realize, though, that many of my Montessori children will be moving on to more traditional programs next year. In order to prepare them for the onslaught of competition in public school, I gradually introduce mildly competitive games into the classroom the last week of school. It was as if we had a different group of kids today. For the most part, all kind words and patient behavior went out the window. I had to literally sit the children down and give them a lesson on how to win and how to lose a game. I strictly enforced a handshake and the words "Good Game" at the end of each round. Children involved in sports were already used to this routine, so they picked it right up. However, they were also the children touting "I'm winning" or "I have more than you" constantly throughout the games. A few children were obviously uncomfortable with the entire concept and chose to steer clear.
In order to prepare the children for the concept of winning/losing, I bring out the "Orchard" game. The children absolutely ADORE this game and it actually improves cooperatve teamwork, while introducing competition. The goal of the game is to collect all of the fruit from the Orchard before the Raven eats it. I highly recommend this game for family fun nights at home: The Orchard Game.
Competition is not something typically found in Montessori classrooms due to the increase in stress levels, however, competition is also part of our American society. If introduced properly, competition can be healthy. But for those of us with children under age 8, let's just stick to enjoying the pleasure of the game.