Montessori education is based on a model of human development. This educational style operates abiding by two beliefs: that psychological self-construction in children and developing adults occurs through environmental interactions and that children (especially under the age of six) have an innate path of psychological development.^{[citation needed]} Based on her observations, Montessori believed that children who are at liberty to choose and act freely within an environment prepared according to her model would act spontaneously for optimal development.^{[citation needed]}