This is Hidden Brain, I'm Shankar Vedanta.

No matter how many weddings you've been to,

it's hard to shake that contagious feeling of optimism.

Couples pledge to love one another in sickness and in health,

for richer, for poorer.

Family members dabbed tears from their eyes,

agreeing that these two people are meant to be together forever.

But so many marriages become unhappy.

Some dissolve, some end in divorce,

and even the successful ones are not without challenges.

No one would deny that long-term relationships are hard,

and in fact, these evidence, they're getting harder.

Over the past few weeks,

our relationships 2.0 series has explored new ways to think

about how we engage with the people in our lives.

We've talked about how to build new bonds with others,

how to strengthen the bonds we already have,

we've looked at how we can respond to conflict,

and how we can work through disagreements more effectively.

This week on Hidden Brain,

we turn to a favorite episode about marriage.

We'll take a closer look at the history of this institution,

...