Gentlemen may prefer blondes but Britain's most sophisticated secret service agent tends to go for brunettes, according to an extensive investigation into James Bond's love life.

Academics who set out to discover what makes the ideal Bond girl found that apart from having long dark hair, she is likely to have an American accent – and to carry a weapon.

The unexpected findings were reached by a team who assessed the physical traits of all 195 female characters in the first 20 Bond movies, then contrasted the characteristics of the 98 who had "sexual contact" with Bond with those of the 97 who did not.

Unsurprisingly, Bond's sexual partners also tend to be younger, slimmer and more attractive than the women he does not bed – and they are less likely to wear glasses.

Those who fit the ideal type include Lois Chiles as Dr Holly Goodhead in Moonraker (1979) and Lana Wood as Plenty O'Toole in Diamonds Are Forever (1971).

The researchers studied all women who had speaking roles or who appeared in two or more scenes in each film from Dr No in 1962, starring Sean Connery, to Die Another Day in 2002, starring Pierce Brosnan. The average age of the women was estimated at 26.

Only 27 per cent of the women were blondes, compared with 40 per cent with black hair, 19 per cent brown and nine per cent red. Those with dark hair were proportionately more likely to get intimate with Bond.

The 18 per cent of women who had long hair were more likely to end up in a sexual situation with 007 than the 22 per cent who had short hair.

More than 90 per cent of the women were judged to be of above-average attractiveness – and the prettier they were, the more likely they were end up in bed with Bond.

Only a quarter of the women in the films had an American accent, but those that did were more likely to end up in a sexual liaison with Bond than the 43 per cent who had a European accent of some kind.

"A majority of female characters engaged in some sexual activity, particularly those in major roles. And the great majority of sexual behaviours involved Bond himself," says the research team, led by Kimberly Neuendorf, professor of communication at Cleveland State University, Ohio.

Three-quarters of the women in the films were white, eight per cent Asian and seven per cent black, with a handful of Arab and American Indian women. One in five female characters were dead by the end of the movie, including many who had had sexual contact with Bond.

Bond was more likely to have sexual contact with a woman if she used a weapon than if she did not.

(Agencies)