The size of a man's finger can show how good he is at sport, research has proved.

Experts at Northumbria University carried out tests to establish male hormonal exposure while in the mother's womb by measuring men's index and ring fingers.

The ring finger has more testosterone receptors than the others, while the index finger is very sensitive to the female hormone oestrogen, making the ratio a good guide.

The longer the ring finger, the higher the testosterone exposure.

And the ratio between the length of the ring and index fingers is one of the most fascinating biological markers, offering clues to phenomena as diverse as sexual orientation, heart disease and footballing prowess.

But the research discovered that the most intriguing link is between the very long ring finger and sporting ability.

A study of professional footballers, including Alan Shearer and Paul Gascoigne, found they had longer ring fingers, on average, than non-footballers.

International footballers had longer ring fingers that non-internationals, and Premiership stars had longer ring fingers than players in the lower leagues.

Homosexual men and women, however, are likely to have a ring finger that is significantly longer than the index, suggesting high exposure to testosterone in determining sexual orientation.