Section A You’d imagine that asking people to rate themselves on a ten point scale in response to the question 'In general, how happy or unhappy do you usually feel?' would only lead to wild inaccuracies.【46】But when scientists compare such basic measures to a full-blown psychological assessment, the results are fairly consistent. It would seem we' re rather good judges of our happiness, and this fact has allowed the use of simple questionnaires and interviews to survey more than a 'million people across many nations. 【47】It’s also quite clear that happiness isn’t just some whimsical concept dreamt up in the 1960s by the hippies and advertising agencies. Richard Davidson at Wisconsin University monitored electrical activity in the brain to show how a highly attractive photograph causes a particular portion of our left hemisphere to illuminate, while a horrific photo stimulates our right side. Indeed, people prone in general to more of this left-portion activity tend to score higher on all counts of good mood, whereas right-siders are decidedly gloomy. The same is true for new-born babies. 【48】What’s more, it seems likely that around 50 per cent of our characteristic level of happiness is an inherited factor. This can be estimated because in 1996, Lykken and Tellegen at Minnesota University compared 663 pairs of identical twins. A further 69 pairs were identical twins who had been reared apart, yet these twins still showed at least a 50 per cent similarity in their self-reported happiness, a far higher percentage than the non-identical twins. Strong evidence indeed that we probably have a genetically predetermined set range. But we should remind ourselves that, as in all aspects of biological inheritance, our genetic potential needs the right environment if it is to unfurl in accordance with our DNA blueprints. So learning to live regularly in the upper end of your happiness set-range is where skill and know-how can pay dividends. How well you play the hand you' re dealt could account for a great deal. And there are other reasons to feel we have everything to play for. For instance, the surveys show that no stage of life is inherently any happier than another, despite everything our parents told us about our school and college days. If anything, life feels better as you get older.【49】Moreover , intelligence as measured by IQ tests is a very poor predictor of life success or happiness. And there’s little if any difference between male and female average self-ratings, though women are more prone to intense swings. The bottom line is, life feeling good pays no heed to age, IQ or gender. It’s open to all-comers. Trouble is, we don’t always know how to generate wholesome, renewable happiness, and sometimes our default response is to reach for the quick-fix, in one form. or another.【50】Yet, we shouldn’t forget that feeling miserable is most often a healthy response, simply nature’s way of telling us to make important improvements. So here’s our chance to cultivate home-grown, evergreen , deeply rooted happiness, without the hangovers. (46)