Civilisation and its contented

The publishers have done Daniel Nettle's new book, Happiness, few favours. The cover, the titchy page size and the subtitle ( The Science behind your Smile ) all suggest one of those cheesy little "how to be happy" books you might give a distant relative at Christmas. It is no such thing. Until its weak ending, it is an authoritative, challenging, even profound analysis of the most up-to-date research into its subject - a topic that, as Nettle says, has provoked and perplexed thinkers throughout history, and almost all of us to this day.

The vast majority of people - at least in Western societies - believe that the purpose of living is to be happy. In this they have been sustained by the ancient Greeks, by the US Declaration of Independence ("all men are... endowed with certain unalienable rights... life, liberty and the pursuit of happiness"), by Jeremy Bentham and the utilitarian philosophers (who defined social good as the greatest happiness of the greatest number), and recently by the tiny kingdom of Bhutan, which has switched its collective goal from gross national product to "gross national happiness".

The odd thing is that nobody has any precise idea of what happiness is. Our language is replete with weighty words whose meanings are blurred: love, truth, honesty and justice, for example. But happiness is peculiarly hard to get a grip on, not only because it is difficult to differentiate from its close synonyms - contentment, pleasure, joy, satisfaction - but because it is riddled with contradictions. How can it be that the grass is always greener on the other side? Why do the things we desire because we are sure they will make us happy so frequently fail to do so? How come every available scrap of evidence - as Nettle convincingly demonstrates - proves that burgeoning affluence fails to increase either individual or national happiness? Why then does virtually every individual and every government in the world - with the arguable exception of the Bhutanese - myopically focus on increasing material wealth? Has everyone lost their marbles?

Nettle's answer is that there has been a widening divergence between humanity's past and present evolutionary needs. To use the well-known analogy, it is as though humanity was a huge tanker, set upon its course in prehistoric times and unable to change direction. Our genes focused on survival, and our brains learnt to make us feel happy about activities - such as increased material wealth - that aided our chances of surviving. Happiness is thus a means to an end and not an end in itself. Unfortunately, having reached this well-grounded conclusion, the author shrinks from accepting its corollaries. Instead, he finally reverts to the forlorn quest for personal happiness.

Nettle should have stuck to his guns. The overriding theme of the book is that bounteous happiness is the great mirage: never reachable. But this is relatively unimportant because for human beings, as for all living things, survival remains the central purpose of life and - affluent though Western societies are - greater affluence helps us survive still longer. Although many people now claim they do not seek great longevity so long as healthy survival is within their reach, there is little evidence they truly mean it. So maybe his publishers were right and Happiness is indeed intended to be just a cheesy "how to be happy" book.

Winston Fletcher is visiting professor in marketing, Westminster University, and chairman, Royal Institution.