Forgiveness is the secret to happy relationships | Life and style | The Guardian Forget retaliation and revenge if someone hurts you, says Dr Luisa Dillner: learn to forgive and you'll be happier and healthier Of the few certainties in life (the best known being death and paying taxes), there is one that is inevitable in close relationships. One day, someone you love or feel close to will hurt you. They may be unkind about your looks, or your friends. They may run off with the au pair, or insult your family. Being close to someone means they can kick you where it hurts the most. And if they do, how will you respond? Retaliate, of course. If not straight away, you can always bear a grudge, so that however long it takes, even as you breathe your last, you will try to exact revenge. Except that vengeance is no longer current. These days, it's all about forgiving. The UN's report Forgiveness, which looks at the psychological research into the subject, cites studies showing the importance of forgiving within personal relationships, as well as between war-torn nations. It makes you healthier and happier, the research says; it makes you feel stronger – it was Mahatma Gandhi who said, "Forgiveness is the attribute of the strong" – and better about yourself. Holding a grudge is bad for your blood pressure (no surprises there), causes anxiety and can reduce your life expectancy. It affects you and not them – the offender has probably forgotten all about what's making you bitter and twisted. In relationships, couples who forgive each other are happier than those who don't – and happier couples are in any case more likely to forgive each other than those who have been making each other miserable for years. But forgiving – as well as being dull compared with revenge – is by no means easy. Forgiveness experts define it as a process that results in your losing the desire to retaliate and letting go of negative emotions. You can forgive but not be reconciled to the person you are forgiving. You can forgive without telling them. No wonder it's not easy: the International Forgiveness Institute at the University of Wisconsin-Madison has a forgiveness model with 20 steps. One of the world's experts on forgiveness is Frank Fincham of Florida State University. "Forgiving brings you peace and closure," he says. "But it takes time. It's more accurate to say to someone, 'I will try to forgive you.' To say you'll forgive and forget is a contradiction. You can forgive only when you remember." So how do you forgive? First think about the benefits (no obsessing over how upset you are, no more feeling anxious or put upon), then about things you might have done wrong (no one is perfect); revisit what happened, seeing if you can understand your reaction and why the other person might have behaved in the way they did. As Fincham says, "It's a free choice to forgive or not, but you can usually make a cost benefit analysis for it."