Desirable versus undesirable, and normal versus abnormal: How does the theory distinguish desirable from undesirable development and normal from abnormal development? Is normal or natural or desirable development defined, or at least implied? If two or more of these terms appear in the theory, are they used synonymously? If not, how are they differentiated? Is abnormal, unnatural, or undesirable development identified? If two or more of these terms appear in the theory are they used synonymously? If not, how are they differentiated? What causes abnormal, unnatural, or undesirable development? What, if anything, can be done to change such development into normal, natural, or desirable growth?