Could a government dare to set out with happiness as its goal? Now that there are accepted scientific proofs, it would be easy to audit the progress of national happiness annually, just as we monitor money and GDP.

It is now possible to quantify people's levels of happiness pretty accurately by asking them, by observation, and by measuring electrical activity in the brain, in degrees from terrible pain to sublime joy.

Nothing keeps people together like the exalted conviction that they alone are to be spared that eternal anguish of hell fire to which everyone else will be condemned.

So what really works? Treatments in jail do some good, but it's mostly too late: finding a family and a job or just growing older make most prisoners eventually give up crime.

The strongest predictor of unhappiness is anyone who has had a mental illness in the last 10 years. It is an even stronger predictor of unhappiness than poverty - which also ranks highly.

People want the right to die at a time of their own choosing. Too many families have watched helplessly as a relative dies slowly, longing for death.

One in six people suffer depression or a chronic anxiety disorder. These are not the worried well but those in severe mental pain with conditions crippling enough to prevent them living normal lives.