8 Year old son who struggles with Impulse Control

This call is from: Kristin Mikkelsen

Nicholeen, how would you handle this? I have an 8-year-old who struggles with impulse control. His behavior at home has improved greatly over the last year, and most of the ongoing issues we see are related to hyperactivity/annoying his siblings. I've always described him as being loving and having a good heart. However, I just found out that over the last three soccer practices and games he has said some very unkind and belittling things to two of his teammates (twin sisters). He's on a homeschool rec team that hasn't won a game, and he's definitely one of the strongest players. I'm so disappointed. So many of his weaknesses seem like issues of too much energy and too little maturity. However, I am devastated with this new meanness. Do you think that we have a deep problem on our hands? How do we handle this?