Final answer:
Multicultural and Cross-Cultural Psychology is the study of psychological differences among people living in different cultural groups.
Step-by-step explanation:
The study of psychological differences among people living in different cultural groups is known as Multicultural and Cross-Cultural Psychology. This field focuses on understanding how culture and environment impact individuals, groups, and societies. Multicultural psychologists typically conduct research within one country, while cross-cultural psychologists compare populations across countries.