Positive psychology has a schmaltzy American feel that might not translate well into a British setting. Dr Nick Baylis of Cambridge University is working with colleagues to "tweak" positive psychology for "British ears". He calls his research the "study of wellbeing" rather than the science of happiness. As a forensic psychologist, he worked with young offenders at Feltham and decided that studying what went wrong in damaged lives was not productive. "I had looked at broken lives. Now I wanted to look at lives that go well."

He founded the charity Trailblazers to give young offenders positive role models. In his Young Lives research project, he interviewed hundreds of accomplished people from Kate Adie to Jamie Oliver about their strategies for making the most of life. Their advice and ideas can be found in www.YoungLivesUK.com and in the book Wonderful Lives.

When Baylis went to Cambridge as Britain's first lecturer in positive psychology, he was treated as a "neo-Nazi", he says. The study of happiness was a "taboo subject". He sent an e-mail to colleagues who might have an interest in wellbeing, and received a reply from only one, Professor Felicia Huppert. She studies the secrets of a happy, productive old age, and theirs is now a fruitful collaboration. The British approach to wellbeing also emphasises good physical health and diet, proper sleep, relaxation and exercise, and spending time in the natural environment.

Given its famously bad health and diet, Glasgow is a city in need of positive medicine. It's become a live laboratory for the new science. Last month, Professor Seligman paid his second visit to Glasgow's Centre for Confidence and Wellbeing, to spread the happiness gospel to Scottish teachers, coaches and businessmen as part of the Vanguard programme, backed by the Scottish Executive. The sceptical Scots seem to welcome Seligman's empirical approach.

Dr Carol Craig, who runs the centre, is passionate about curing Scotland's epidemic of pessimism and low self-esteem. She points to many indicators of malaise: the Scottish suicide rate is double the English one, and antidepressant prescribing is 40% higher. A new UN report says that Scotland is the most violent country in the developed world. Scottish children are among the least confident anywhere, according to the World Health Organization.

Craig believes that the dark, forbidding nature of Calvinist religion is responsible for the dour Scottish psyche. "We're a culture that encourages feelings of lack of self-worth. We're a culture that goes out of its way to make sure people don't feel good about themselves," says Craig.

From a young age, Scots are taught humility, modesty and conformity. Scottish humour often pokes fun at those who "get above their station". Craig speculates that the high rate of emigration from Scotland has denuded the country of optimists and left too many pessimists behind. Could any of this be linked to the fact that men in one part of Glasgow, Shettleston, have a life expectancy of 64? (Scottish men, on average, live to 73.) And that west Scotland is the unhealthiest region in Europe, with high rates of heart disease, cancer and strokes? Has anyone found a causal link between happiness and health?