A psychologist says a simple question can help you figure out if you and your partner can handle having a kid

You and your partner will never be 100% "ready" to have a kid. At least, not in the same way that you two will be ready to buy a place because you got approved for a mortgage and bought a lawn mower.

When it comes to having a baby, you and your partner kind of have to "approve" yourselves — as in, assess the strength of your relationship to see if it can withstand the stress of child-rearing.

If that sounds super nebulous, it is: The process looks different for every couple. But your answer to one question in particular can give you some insight into what your life would look like post-baby: How do you manage joint decision-making?

That's according to Carl Pickhardt, a psychologist who's written multiple books about parenting, including, most recently "Surviving Your Child's Adolescence."

Joint decision-making, Pickhardt told Business Insider, is essentially what parenting is.

Your baby will be crying in the other room; one partner will want to go pick him up and comfort him, while the other will think it's better to leave him alone. Or, years later, your adolescent will want to stay out late at a party, and you and your partner will disagree on whether it's a great idea.

"If you have parents who have a hard time bridging disagreements," Pickhardt said, "that's probably not a great sign. They've got to be able to know how to communicate, and how to change, and how to make concessions, and how to compromise."

Otherwise, Pickhardt added, you and your partner will wind up making separate decisions about the kid and being frustrated with each other's choices.

There are a few scenarios to look out for. If one of you currently makes all the decisions; if there's no "us" in your relationship because each partner makes decisions independently; or if no decisions get made unless you and your partner make them together, that probably doesn't bode well for your parenting experience.

Ideally, you want to see the intimacy between you two increase after each joint decision you make, Pickhardt said. If instead, it drives you apart, that suggests your life as parents will be pretty stressful.

Above all, know that shared decision-making will only get more complicated once your baby arrives.

"Sometimes people will say, 'Well, sharing is easy.' Sharing is not easy," Pickhardt said. "Sharing is brutally hard to do."