Making a simple list with your partner can save your relationship — and leave you a lot less stressed

On one episode, Vanderkam and her cohost, physician Sarah Hart-Unger, talk about the "mental load" of parenting — i.e., all the psychological energy it takes to remember to sign Davie up for swimming lessons and drive Janie to the dentist.

Vanderkam and Hart-Unger set out to solve two problems. One, how can you make the mental load more reasonable and even enjoyable? And two, if you're a co-parent, how can you split the responsibilities relatively evenly?

Their solution is simple but elegant, and it applies just as easily to couples with and without kids. There are two steps:

1. Each person writes down all the family responsibilities they're currently taking care of.

2. Each person shares which of those responsibilities they enjoy, and which they don't.

In the process, you might discover that you're shouldering a considerably smaller responsibility of family responsibilities than you thought.

Vanderkam shared a simple but telling example: She would never even think of putting air in the kids' bicycle tires. But somehow, they always have air — her husband makes sure of it.

An oft-cited study found that each partner in a couple tends to overestimate how much they contribute to the housework, and to the relationship in general. You may be less of a housework hero than you think — which is important to realize, especially if you're starting to resent your partner for being a bum (or vice versa).

Now to that second step: Figure out which responsibilities you enjoy. Maybe you're scrubbing the shower every weekend because otherwise it'll get gross, but honestly, you hate doing it. Is it possible to hire a housekeeper?

"If there are things uncovered that both of you hate doing, then that may be a signal that neither of you need to do it, or maybe that's something that can be outsourced," Hart-Unger said.

Or, maybe your partner wouldn't mind putting in some elbow grease, and you could "trade" her another chore. It's kind of romantic.

The bottom line here is that passivity rarely gets you anywhere. That is, muttering under your breath that this dog should really be Kelly's responsibility, or assuming that you're doomed to a lifetime of de-rusting the bathtub is not all that productive.

Have an honest conversation about this stuff with your partner — it'll free up some mental space and bring you two closer.