“Marriage has a self-expressive emphasis that places a premium on spouses helping each other meet their authenticity and personal-growth needs,” he writes. “The pursuit of self-expression through marriage simultaneously makes achieving marital success harder and the value of doing so greater.”

Finkel writes that while “the institution of marriage in America is struggling ... the best marriages today are better than the best marriages of earlier eras; indeed, they are the best marriages that the world has ever known.”

In The All-or-Nothing Marriage, Eli Finkel, a professor of psychology at Northwestern University, traces the history of the institution over what he sees as three thematic eras: marriage for practical reasons, marriage for love, marriage for self-expression/fulfillment/meaning.