5 habits people in happy marriages avoid at all costs, therapists reveal

Marriages are hard work and it takes much more than love for them to survive the test of time. While some marriages break down as soon as challenges arrive, others thrive and become stronger over time. But, what are couples in happy and healthy marriages doing differently which sets them apart from the rest? Dr. Jacqueline Olds and Dr. Richard Schwartz-- couples therapists and associate professors of psychiatry at Harvard Medical School-- who have been married for roughly 50 years recently shared their insights with CNBC. Here we list their advice on the five habits people in happy marriages avoid at all costs:

When you argue with your partner, the sooner you apologize, the better.

It’s easy to shut down or stay upset—we get it. Holding a grudge doesn’t magically go away with age or experience. But the longer you let hurt feelings linger, the harder it becomes to truly talk things out.

A real apology isn’t about shifting blame or saying something like, “I’m sorry you felt that way.” Happy couples still have their disagreements—they just know how to make things right.

The key? Take responsibility. A good apology is about owning your part and showing your partner you care more about the relationship than being right.

Happy couples try not to correct each other in public.

For instance: When a couple is out with their friends and one of them starts telling a story, sometimes the details are a little off. Sure, there’s a natural urge to jump in and set the record straight—but over time, couples in happy and healthy marriages have learnt that it’s just not worth it. In the big picture, letting those little inaccuracies slide is far more valuable than being “right”. What really matters is making each other feel supported, not undermined. And it's the same for handling disagreements.

Dr. Jacqueline Olds and Dr. Richard Schwartz told CNBC, "One thing we hear a lot from clients is, 'You treat everyone else better than you treat me!' And often, their partner responds with something like, 'I’m just being my real self. Real love means not having to pretend.'"

They further shared that this kind of tension usually pops up when people start taking each other for granted. Out in the world, they’re polite and considerate with friends, coworkers, even strangers. But at home, that same effort and kindness disappear.

Here’s the truth: using “authenticity” as an excuse to stop being kind and thoughtful doesn’t make a relationship more real—it just makes it more hurtful. Being your true self shouldn’t mean being careless with the person you love most.

If you think something nice about your partner, don’t keep it to yourself—say it out loud. A sincere, specific compliment can go a long way in strengthening how you see each other and your relationship, the experts share.

"We’ve had plenty of moments where one of us does something great, and the other notices it... but says nothing. After being together for a long time, it’s easy to fall into the habit of assuming your partner just knows how you feel... But here’s the thing—no one ever gets tired of feeling seen and appreciated. Sharing those positive thoughts keeps the connection strong, especially as you both grow and change over time," they added.

The couples therapists also shared that one of the most common and biggest mistakes couples usually make is to take each other for granted. Instead of showing how much they love and care for each other every day, they wait for special moments and days to express themselves.

"If you’re waiting for your partner to soften and show you how much they care, you’ll likely be waiting a long time. Those cracks (fights) can then turn into breaks that are tougher to heal. In moments like these, try something simple like cooking their favourite meal. Remind yourself how much they enjoy it and revel in taking the time to craft it for them. Then tell them about the positive feelings that stemmed from the activity. This way, you’re not out in the cold waiting for love in return. Instead, you’re taking control of the situation and building an environment where it can flourish again," the experts shared.