Scientist reveals simple everyday act couples can do together to feel happier by 20 percent

A scientist has revealed there's a simple, everyday thing couples can do together to boost their happiness.

Keeping the spark alive in a relationship takes work, while the secret code to a successful, long and happy partnership is one not everyone has managed to crack.

Household chores and domestic labor is arguably the worst part of adulthood, and in relationships lamenting the laundry or dodging the dishes can become a contentious issue.

However, according to one psychologist, there's an easy trick couples can incorporate into their daily lives which surprisingly involves a common chore.

And not only can doing it make them feel happier by a whopping 20 percent, but the expert claims completing the task could be better than flowers or other grand gestures of appreciation.

Couples can boost their happiness by what they do together after enjoying a romantic meal (Getty Images)

Doctor Hannah Lawson, who has more than 12 years’ experience in relationship counselling and behavioural psychology, revealed to The Daily Mail that washing up holds the key to a harmonious partnership, providing one person isn't left with the load alone.

The pro said couples who engage in the seemingly dull errand together often say they feel closer, appreciated and happier in their everyday life.

That's because collaborating on the task promotes fairness and teamwork, Dr Lawson said, adding: "When you share even small chores, you show each other that you are equals. And that is often far more powerful than big romantic gestures."

Sharing the burden together also creates a space for couples to talk about their day, make plans or enjoy a seemingly mundane but intimate moment together without any disturbances.

The doctor said it creates an intimate moment (Getty Images)

When the dishes are constantly left to one person, it can build resentment and create an imbalance, she continued, stressing that it must be completed together.

For example, she suggested one person could wash and another dries, and popping some music on can also make the task seem more enjoyable.

"Think of it as a small daily ritual that pays you back with trust, respect, and a stronger emotional connection," the doc said.

Her insight also comes as a report from the Council of Contemporary Families discovered women in heterosexual relationships who are tasked with completing the dishwashing solo even suffer less sexual satisfaction compared to those who split the dishes with their partner.

"Sharing responsibility for dishwashing was the single biggest source of satisfaction for women among all the household tasks, and lack of sharing of this task the single biggest source of discontent," the scientific study added.

Women in heterosexual relationships report higher feelings of discontent if their partner doesn't help out with the dishes (Getty Images)

Dan Carlson, Assistant Professor, Family and Consumer Studies at the University of Utah and author of the study, summarised: "My findings suggest that the most mutually beneficial housework arrangement for couples is one where tasks are shared equally.

"Men may be equally satisfied doing no housework or sharing all or most tasks equally, but since women’s highest satisfaction is when all or most tasks are shared, the route to a happy relationship appears to lie in sharing.”

Dr Lawson made her comments in partnership with bathroom ad kitchen expert, Plumbworld, which added in a statement: "A simple five-minute routine can keep your sink clear – and your relationship healthier.

"Washing up together is one of those small habits that can make a huge difference.

"It supports better hygiene, fairness, and even improves your emotional wellbeing as a couple."