That's men for you/Padraig O'Morain's guide to men's health:You know that irritatingly cheerful chap who's always bursting with optimism no matter how bad you feel?
He's the one who jolts you out of your gloomy Monday morning thoughts with a "Cheer up, it might never happen" and who brays like a donkey at his own brilliance while you wish you had a machine gun to hand.
The bad news, I'm afraid, is that this annoying individual may be in a healthier condition than you simply because of his boundless optimism.
Men appear to benefit more than women from being optimistic, but women benefit too. It is all to do with your levels of cortisol, a hormone linked with stress and ill health if you get too much of it.
A study published in the British Journal of Health Psychology sets out the results of an experiment on optimism conducted at the City University of Hong Kong.
Eighty healthy men and women gave samples of their saliva and completed questionnaires about their levels of optimism.
When the saliva samples were analysed, the researchers found that men who were in an optimistic mood had lower levels of cortisol when they woke up in the morning.
In women, optimism did not seem to affect their levels of cortisol at the start of the day.
However, if men or women had been generally optimistic for the previous month their cortisol levels tended to be lower throughout the day.
Indeed, even if they were in a bad mood on the day the sample was taken, the cortisol level was lower if they had been optimistic for the previous month.
This seems to provide evidence that the positive state of mind is good for your physical health, at least when it comes to cortisol levels.
So that optimistic chap who makes you grind your teeth with frustration is benefiting from low cortisol levels while the stress he is inducing in you, his victim, is probably sending your cortisol levels through the roof.
And if all this sends you to an early grave, he will probably be there, braying and prancing about and urging the mourners to "Cheer up, it might never happen."
Cultivating optimism is, among other things, a matter of accepting that you have the skills and the ability to handle whatever is going to come up during the day.
If you are a pessimist, you will say that is ridiculous and that to hold such a belief is to fool yourself.
Well, yes. Optimism does indeed involve a certain amount of pulling the wool over your own eyes. But so does pessimism. It is just as unrealistic to tell yourself that you do not have the skills or the ability to handle whatever is going to come up in your life as to tell yourself that you have these skills.
So what you need to do is to quit arguing about it and acknowledge that you have the skills and the resources to handle most of the things that you will face.
In holding that belief, you will be right a lot of the time and wrong some of the time. If you go around being miserable and assuming the worst you will, in my opinion, be right some of the time but wrong a lot of the time.
So why not take the more optimistic route? I do not mean to suggest that you need to go around like that irritating fellow mentioned above.
You probably would not want to be like him anyhow. Nor do I suggest that you go around saying everything in the whole world is fine and dandy.
But quietly reminding yourself that you do have the skills and resources to handle most of what you will have to handle today is a good way to cultivate an optimistic attitude. That is the recommendation of psychologist Dr Martin Seligman who studies the effect of positive attitudes on people's behaviour.
Try it for a while and see what happens.
The worst that can happen, if you're a pessimist, is that you will be a bit less miserable than you are now.