Conducting the same study within the same standardised procedure in clinical patients in more than one country to compare and see if symptoms of disorders are universal or if they differ.
If all symptoms are the same then it can be argued that CD are a consequence of nature, however if they differ, then it can be argued that the CD is due to nurture/culturally determined
AO1 - etic and emic
Etic research seeks universals of human behaviours, looking at different cultures, and comparing them
Emic research is interested in the distinctiveness of human behaviour and looks in detail at a particular culture and tries to devise research scenarios that are meaningful within that particular culture
