Question

How does the explanation of the origin of the term “alter ego” help explain its later use in popular culture and literature?

Answer 1

The term is of Greek origin and it was used to detonate the second self. the term implied the possibility of good and evil to live in one person simultaneously.
The term has been used over generations by poets and writers where they depict  a character with both identities,secretly hidden. The character may be in control of the alter ego or not.

Answer 2

Answer:

The meaning of the term is "other I"  in latin an refers to a second part or identity that is contrary to the one that is commonly known.

Explanation:

The phrase "alter ego" comes from latin and means "other I".  It was used in Rome by phiposopher Cicero to describe another part of himself. Later on the term would be used for different psychologists to refer to different personality disorders. Eventually, the term became popular enough to be used by artists creating literature based on that concept , for example,  the tale of Dr. Jeckyll and Mr. Hyde.