And we didn't know this ?

It is something one half of the population has long suspected - and the other half always vocally denied. Women really do talk more than men.

In fact, women talk almost three times as much as men, with the average woman chalking up 20,000 words in a day - 13,000 more than the average man.

Women also speak more quickly, devote more brainpower to chit-chat - and actually get a buzz out of hearing their own voices, a new book suggests.

The book - written by a female psychiatrist - says that inherent differences between the male and female brain explain why women are naturally more talkative than men.

In The Female Mind, Dr Luan Brizendine says women devote more brain cells to talking than men.

And, if that wasn't enough, the simple act of talking triggers a flood of brain chemicals which give women a rush similar to that felt by heroin addicts when they get a high.

Dr Brizendine, a self-proclaimed feminist, says the differences can be traced back to the womb, where the sex hormone testosterone moulds the developing male brain.

The areas responsible for communication, emotion and memory are all pared back the unborn baby boy.

The result is that boys - and men - chat less than their female counterparts and struggle to express their emotions to the same extent.

"Women have an eight-lane superhighway for processing emotion, while men have a small country road," said Dr Brizendine, who runs a female "mood and hormone" clinic in San Francisco.