We're all wired for kindness. We act kindly because we know instinctively it's the right thing to do, and believe the world could do with more kindness. A network of relationships sustained by kindness can benefit us all, both physically and psychologically. It can slow the effects of ageing too. People under stress tend to be more prone to infections and disease. As we get older, the immune system weakens. But studies have shown that both giving and receiving kindness boosts the immune system. A positive attitude to life's stressors helps us recover faster from illness and strengthens our ability to fight off disease. Kindness can even slow the formation of wrinkles. Groups of unstable molecules called free radicals produce something called oxidative stress in the body, which causes nasty physiological reactions, including hardening of the arteries and memory loss. It also leads to visible signs of ageing. But being kind produces a substance called oxytocin, often known as the 'love hormone', as we make more of it when we feel love, share positive contact and have sex. The less oxytocin we have, the more free radicals we get. A study at the University of California, Riverside, [asked] volunteers ... to perform five acts of kindness a week for six weeks. These included donating blood, paying for someone's parking or visiting an elderly relative. Using established measurements of happiness, psychologists found those who performed the kind acts became happier, while a control group who didn't, well, didn't.