In the book A Child Called It, what happens involving a shopping cart?

One day, David's mother had to go to the grocery store. Usually David was left behind in the store, but for one reason or another, his mother allowed him to accomapny her inside. David was instructed to hold onto the cart and keep his head bent toward the floor, but David, considering this a perfect moment to rebel did everything he was told not to do. He made comments to his brothers, caused a scene, and in the end, he received a "thrashing" before they even made it to the station wagon. (Page 142)