Shankar Vedantam

And with the rise of this new idea came another.

If marriage was once seen as a partnership between people from similar backgrounds and similar social classes, the new model of marriage began to celebrate the coming together of people who were supposedly radically different from one another.

Now this idea came that men and women were totally different and you could only have access to the emotions, resources, abilities of the other by getting married and staying married.

You were incomplete without it.

In practice, this dovetailed with a changing economic landscape in the country where men increasingly became the breadwinners and women became homemakers.

The 1950s sitcom, Leave It to Beaver, makes clear this division between male and female roles.

Talk to me about this idea, Stephanie.

So clearly, gender biases played a role in how we came to think about marriage.

The idea of the love match may have been controversial at first, but when concerns were raised about how people from different backgrounds would stay together when they didn't have the bond of shared work or the larger framework of a shared community,

Advocates for love marriage said men and women would stay together because they needed one another to feel psychologically complete.

This theory was later appropriated in romantic stories and movies.

Think of the saying, opposites attract.

But as the divorce rate in America surged in the 1970s and 80s, many started to think that what you should look for in a mate was not your opposite, but someone who shared your interests and values.

It wasn't quite the same as one baker looking to marry another baker, but more along the lines of people marrying others with similar educational backgrounds and similar cultural and political attitudes.

And that's one of the big challenges of love today, because we spent 100 years trying to get people to see love.

a difference as erotic and the source of love.

And now our big challenge is how do we make equality erotic?

How do you make equality erotic?

Where is the sizzle in consensus and compromise, in child care pickups and doctor's appointments, in a lifestyle symbolized by a Honda Civic rather than a flashy Ferrari?

When we come back, we'll answer that question.