They aren't good sports.
First graders feel like they must be the winner. They change rules to benefit themselves, and they quickly accuse others of cheating.
What you should do: Avoid games that determine a winner. Instead, encourage games that involve building skills, working together and accommodating the skill levels of others. Kids this age love cooperative activities, projects and tasks.
Do you want to learn more about this common phenomenon? We've got an article all about it. Click here to read "Why Are First Graders So Competitive?"