Cameron Diaz has admitted that she doesn't know if anyone is really monogamous in a relationship.

The 41-year-old actress told InStyle magazine that people mostly chase after marriage because they think it will make them happy, but once they get it, they're miserable, E! Online reported.

Everyone has the same instincts as animals, but they live in a society where it's been ingrained in them to do these things, she continued saying.

The 'Charlie's Angel' star, who's on cordial terms with her former partners including Justin Timberlake, Jared Leto, and Alex Rodriguez, added that she's grateful for all of her relationships and all the things she's been through have been a lesson.