WHAT struck me about Barack Obama's victory in the US Presidential elections this week was the optimism with which he opened and closed his emotional and intensely moving acceptance speech.

Suddenly the world seemed a little less grim. Hope was bursting on to the horizon. He began with the words, “America is a place where all things are possible”. And, in case there were any doubters in his ecstatic audience, ended with the chanted message: “Yes, we can”.

Well, who really knows whether that's true? Sceptics might call such optimism “hope in the face of reason”, and question how one man can possibly change all that is wrong with the United States and, indeed, with the world.

But optimism itself can be a surprisingly powerful force that is shown to extend lives and improve people's health and wellbeing. Optimism comes in two varieties: dispositional and situational. The former is hardwired. Some of us are just sunnier than others, no matter what our circumstances, thanks to the helpful deck of genes that fate dealt us when we were born.

Situational optimism, on the other hand, is what we feel when we use information to calculate success at a particular point - when the state of Virginia went for Obama for instance. What is curious (and contrary to our assumptions) is that pessimism is not the opposite of optimism. They are actually quite separate traits. And while optimism is good for our health, pessimism is not.

Clues about the effect

of optimism came from a study of a group of elderly nuns, who had all written brief autobiographical statements on their entry into holy orders at the age of 20. These were categorised on the basis of how many positive statements they included. The nuns who showed the least positivity died on average nine years earlier than those who were most positive, despite them all having lived as similar a life as it is possible to have.

Furthermore, interviews with older people have revealed that an optimistic outlook is linked not only to a longer life, but also to being a non-smoker, having only a moderate alcohol intake, taking brisk walks and doing regular exercise. So there is something about the health practices of optimists that make them take better care of themselves. Interestingly, optimists also tend to rate their own health as being better, even when it is not.

On the other side, even moderate levels of pessimism have been shown to have an effect on blood pressure and, in those recovering from coronary surgery, greater release of enzymes that are associated with heart attack.

A very strange twist is that it isn't a clear-cut situation, with optimism all good, and pessimism all bad. Optimism can be a predictor of birth complications and even more strangely has been found in studies to be associated with a reduced immune function. And, perhaps, this is where the need for careful realism comes in. World-weary cynics are rarely floored by grief when outcomes are not as sunny as the Pollyannas among us might hope. They just get on with it.

The best approach is to be a moderate optimist. However, as a convinced glass-half-full optimist, I still believe that we have seen a world-changing event this week.

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