There is only one stage domain

The study used the model of hierarchical complexity (MHC) to test the theory that different domains in development would develop in synchrony, allowing an individual to solve tasks from various domains using the same mental structure for each task. The MHC instruments used were the empathy, helper person, counselor patient, breakup, caregiver, algebra, balance beam, infinity and laundry instruments. The instruments can be categorized as belonging to two different subdomains, the social subdomain, and the logic/mathematics/physical sciences subdomain. Instruments in this social subdomain measure developmental stage in a variety of social contexts. These social contexts included empathy for person after an accident, guidance and assistance by a helper, counseling patients, understanding romantic breakups, and caring for children and infants. The other subdomain is composed of mathematical (algebra & infinity), logical (laundry), and physical science (balance beam). In order to conclude how related the performances were, three analyses were carried out. First, Rasch analysis yielded person scores akin to person stage scores. Second, regression analysis was conducted to assess how well the order of hierarchical complexity (OHC) of the items predicted the Rasch difficulty of the items. Third a principal axis factoring was carried out with the person Rasch scores for every instrument. Irrespective of domains, if each instrument loaded on the first factor with all the factor scores over .7 and if the first factor accounted for more than 70% of the variance, then that would show that all instruments were part of a single domain. In each case the MHC accounted for a large amount of variance with r values over .7. The principal axis factoring showed that person scores on each instrument loaded on the first factor (90.51% of the variance). All the factor scores on the first factor were over .85. There were very low loadings only on the second factor (4.947% of the variance). This implies that the instruments from the social subdomain and instruments from the logic/mathematics/physical sciences belong to a single domain.