When it comes to your child's development, their early years are the most important. These early years take place between birth and 8 years of age. It's during this time that children are rapidly developing both physically and cognitively. They are also developing social skills, as well as emotion regulation and language. Development in all of these areas is necessary for learning. For this reason, when a child enters school, it's important that they get evaluated for any developmental disorders that might hinder their ability to learn.