The digest guide to... happiness

You can will yourself happier. Nathaniel Hawthorne likened happiness to a butterfly, "which, when pursued, is always beyond our grasp, but which, if you will sit down quietly, may alight upon you." Poetic but probably wrong according to recent psychology research. A study earlier this year found that people who made a conscious effort to improve their mood while listening to upbeat music felt happier afterwards than those who just listened passively.

Happiness breeds success. It's obvious that success in love and work makes most people feel happier, but there's also evidence that the causal direction runs the other way too. Studies have measured people's happiness and then observed their success over subsequent years, simultaneously controlling for other extraneous factors that might have caused both the happiness and later success. These studies found that happiness tended to precede fulfilling work, satisfying relationships and a long life. Short-term mood boosters also trigger increased altruism and sociability.

Other people experience more misery than you realise. We tend to put on a brave face in public, which may explain why psychologists have found that we tend to underestimate other people's experience of negative emotions – even our close friends. Related to this, there's evidence that we need to be careful about promoting happiness. Although well-intentioned, happiness campaigns may lead people to cope less well with their negative emotions because they feel there's a societal expectation to be happy.

People with mental disorders can still experience joy. While we have a habit of overestimating most people's happiness, we risk making the opposite error when it comes to people with depression and other mental disorders. A study published in 2011 made the important observation that many people with mental illness still experience frequent bouts of positive emotion. From a survey of over seven thousand people, Ad Bergsma and his team found that those with mental illness were less happy than those without, but that the majority of the patients said they "often felt happy" during the preceding four weeks.

Our average happiness levels are remarkably robust. Rather like a pond that soon returns to calm no matter the size of the stone you throw in it, psychological research has shown that people's sense of happiness is stubbornly immovable, regardless of how good or bad the experiences one endures. This can be a good thing. Healthy people think their mood will plunge if they develop a chronic illness, and yet research with kidney patients shows that they experience just as much positive emotion as healthy people. We also tend to overestimate the impact of money on our happiness.

Frequent, subtle mood-boosters are key to happiness. Given the largely immovable nature of our  happiness levels (psychologists liken this to a "hedonic treadmill"), high impact positive events like winning the lottery are only likely to have a short term influence on our positive emotion. According to a 2008 study, the secret to increasing our average happiness levels is to engage in frequent, more subtle mood-boosters. They surveyed people leaving religious ceremonies or leaving the gym and found that they were happier than before they'd arrived. What's more, the more they'd attended over the last month, the happier they tended to be.

Multiply your joy by sharing your good news. Telling others about our good news gives us a special enduring happiness boost. Simply writing about the news or having a chat with someone in general does not have the same effect. However, the benefit is not a given. We need the listener to respond enthusiastically, in what researchers call an "active constructive" style. In fact, past research shows that the way friends and family respond to positive events in our lives is a more reliable predictor of the future health of that relationship than the way they respond to our negative news.

We're happier when busy but our instinct is for idleness. Psychologists think it's an evolutionary hang-over to conserve energy. It means that, given the choice, we tend to choose the lazy option, even though it doesn't make us happy. Fortunately, research shows that providing people with even the most specious reasons to be more busy and active is enough to get them going and they end up feeling happier as a result.

Become a political activist. Aristotle argued that we're political animals at heart and that active involvement in society fulfils a basic human need. Research published in 2009 appeared to back him up. Malte Klar and Tim Kasser found that students involved in political activism were happier than their uninvolved peers. What's more, students encouraged to write to their college cafeteria director calling for more ethically sourced food said afterwards that they felt more energised and alive, as compared with a control group who wrote calling for more choice.

Retail therapy works. In 2011, researchers had 69 undergrads keep diaries of their shopping habits and mood for two weeks. Sixty-two per cent of purchases had been motivated by low mood, 28 per cent as a form of celebration. The retail therapy purchases were overwhelmingly beneficial, leading to mood boosts and no regrets or guilt, even when they were unplanned. Only one participant who'd made a retail therapy purchase said that she would return it, given the opportunity. "There seem to be positive consequences to buying oneself a small treat; one does feel better," the researchers said.