penis size , it will affect their sex life.

"In some cases it will affect how they behave around other men. And one has to remember that most people make their comparison with a flaccid penis ¡ª at the urinal or in a change room. The only erections we tend to see are the very big penises on porn stars ¡­ and my interview subjects didn't feel threatened by these giant penises because they felt they weren't real. It's in the real world that anxiety takes root."

Mr Fox's research is still in its early days, but one of the intriguing findings is that "a good penis size can compensate for other character flaws".

"So you may not be the nicest person around, but if you have a big (penis) you'll tend to feel good about yourself ¡­" he says.

In fact, the bigger penis may have no other useful role beyond being a comfort to its owner.

"We don't have any real evidence that there is anything gained from a large penis," says Dr Stephen Juan, Sydney University academic and author of The Odd Sex. "The ancient Greeks fought in the nude ¡­ in combat you reached for anything you could, so having a large penis would have been disadvantageous."

Contrary to Mr Fox's position, Dr Juan says the object of envy is the super-sized male porn star. "Just as men will see a (Hollywood) movie and look at the attractive, suave, charming, athletic male character and want to be like him ¡­ he will now look at the porno performer and want to be like him. Probably if we didn't have the porno industry, we wouldn't have the extent of this envy."

Meanwhile, my pills are in the mail. But the important thing is not to worry.