How do we know that Myrtle Wilson is not an intellectual?

Myrtle only penchant for reading and expanding her mind is the latest edition of the gossip magazines.

At the news-stand she bought a copy of Town Tattle and a moving-picture magazine, and in the station drug-store some cold cream and a small flask of perfume.

Several old copies of Town Tattle lay on the table together with a copy of Simon Called Peter, and some of the small scandal magazines of Broadway.