There are 5 reasons :

1.  Developing a sensitivity to various cultural heritages and backgrounds in order to better understand your own identity
2. Enhancing personal and social interactions
3. Understanding the basis for and at least on a personal level, helping to solve cultural misunderstandings, miscommunications, and mistrusts
4.  Recognizing and respecting ethnic and cultural diversity in order to value the ways in which it enhances and enriches the quality of our civilization
5.  Assisting readers in becoming effective citizens of our national communities.

=>> actually, we should study this in order to unerstand deeply not only our own culture but also other culture in the world