It’s not a message likely to be found on many Valentine’s cards but research has found that couples who argue together, stay together.

Couples who argue effectively are 10 times more likely to have a happy relationship than those who sweep difficult issues under the carpet, according to a survey of almost 1,000 adults.

Many couples mistakenly believe that avoiding discussing sensitive issues means avoiding an argument, which, in turn, will be good for their relationship, said Joseph Grenny, co-author of the New York Times bestseller Crucial Conversations.

“But the biggest mistake that couples make is avoidance,” he said. “We feel something but say nothing. At least until we can’t stand it anymore. So we wait until we are certain to discuss it poorly before we bring it up.

“We tend to avoid these conversations because we are conscious of the risks of speaking up, but unconscious of the risks of not speaking up,” he said. “We tend to only weigh the immediate and obvious risks without considering the longer term costs to intimacy, trust and connection.”

More than four in five respondents to the survey said poor communication played a role in a previous failed relationship.

One half cited poor communication as the significant cause of the failed relationship. But crucially, Grenny said, fewer than one in five believe they are usually to blame when a conversation goes poorly.

“The biggest unconscious mistake couples make is failing to take emotional responsibility for their feelings,” he said. “We think others are ‘making’ us feel the way we are – and fail to see our role in our own emotions. That’s why when we discuss our concerns with our loved one we are so often filled with blame and provoke defensiveness.”

Grenny said the three most difficult topics for couples to discuss were sex, finances and irritating habits.

“The success of a relationship is determined by the way in which sensitive issues are debated,” he said. “True love takes work. Real intimacy is not just about love but is also about truth. And crucial conversations are the vehicle for surfacing truth in a way that accelerates a feeling of intimacy, trust and connection.”

How to effectively argue with your partner

-Manage your thoughts

 - Soften your judgments by asking yourself why a reasonable, rational and decent person would do what your partner is doing

- Affirm before you complain

- Don’t start by diving into the issue. Let your partner know you respect and care for them first

- Start with the facts

- Strip out the accusatory, judgmental and inflammatory language

- Be tentative but honest

- Having laid out the facts, tell your partner why you’re concerned. But don’t do it as an accusation: share it as an opinion

- Invite dialogue

- If you’re open to hearing your partner’s view, they’ll be more open to yours