Preschoolers pride themselves on mastering big-kid skills and love the attention their achievements win them. So if they lose a game of checkers or can't finish a puzzle, it's frustrating enough to make them act out physically, even when they know they shouldn't, says Judith Wagner, Ph.D., professor of child development and education and director of the Broadoaks Children's School at Whittier College in California.

As kids get more experience winning and losing and start to understand others' feelings better, they can become good sports (or at least not terribly sore losers). To help the process along:

Emphasize the role luck plays in many games ("Wow! That was a lucky spin!") so your child learns that winning isn't always related to how "good" he is.

Teach him to praise his playmates' successes, and have him say "Good game!" to every player at the end.

Applaud his efforts during the game. Saying "Great job waiting for your turn!" or "I loved how you took time to plan your next move" shows that how he plays is more important than winning.

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