If you ask your children a question like “Why did you do it?” they are likely to interpret it as an attack and respond defensively. The question implies that they acted without thinking or were inconsiderate. No wonder they get defensive!
When children’s behavior causes a problem, it’s better to help them figure out a solution rather than focus on defending their actions. Let’s pretend a child is coloring a picture and proceeds to do some coloring on the table instead of the paper. You could simply state “I see you’ve got some crayon marks on the table. Do you know how to clean that off?” With this type of question, you are guiding your child to finding a solution.
Asking children questions like “What were you thinking?” or “How could you do that?” encourages them to defend their behavior. When you can help them focus on finding a solution to the problem at hand, they learn to make amends for their mistakes instead of excuses for their behavior.