I find many of the boys and more physically-oriented girls seem to enter an angry phase around the age of six. Door slamming, yelling, stomping of feet, true
Six-year-olds can become frustrated rather quickly, so rhythm and connection are so important. Modeling what you want to see, and ignoring what you can, is also important for this age.
One thing that seems to work exceptionally well for this phase is to make sure that this child is really getting their physical energy out – lugging, tugging, pushing, pulling, really working hard and sweating! Think of what physical projects you really could do together around the house or yard.
I think work also can work as restitution as well. If a six-year-old’s temper tantrum (and yes, six-year-olds can still have temper tantrums and other physical expressions of their anger) really disrupts the whole family’s rhythm and work, that child can work in practical ways to help you, with you, around the house in exchange for that time.
Anger and aggression are not the same things. If a six-year-old is being aggressive due to frustration and anger, then it is our job to step in and help that child through physical activity and restitution.