Answer: Comparative-historical
Step-by-step explanation:
The comparative historical research is one of the type of approach that basically helps in examining or evaluating all the historical phenomenon and the social structure.
By using the comparative historical approach or method we can easily comparing the different types of societies and the cultures and the main objective of this approach is that it helps in understanding the main mechanism.
According to the given question, Erikson is the sociologist and he is using the comparative historical research methodology for evaluating the given situation Therefore, Comparative historical is the correct answer.