Can Children Understand Sin?

In the last few years we have had the idea that children should not be taught about sin and that confession should not be required before communion because it would give children a wrong sense of guilt. However, every child three years of age and older understands the meaning of a broken relationship, which is the essence of sin. Just let a mother tell a young child, 'Mommy no longer loves you', and you will see the disturbance caused by a broken relationship.