even if human development is continuous, there is some value in stage theories of development. a stage theory of development allows experts to examine the developmental progress of individuals and establish a basis for developmental changes. this can identify developmental issues earlier. stage theories can also researchers who are examining physical development examine discrete changes in the brain that allow certain developmental milestones to be reached. finally, stage theories can give one a sense of where an individual is developmentally, and can prepare the person for changes that may occur during their lifetime.