The mathematical formula that proves couples should NOT have sex on their first date

The mathematical formula that proves couples should NOT have sex on their first date

By David Derbyshire
Last updated at 1:39 AM on 17th January 2009

Women increase their chances of being lucky in love if they avoid sleeping with men on the first date, scientists say.

Using a complex mathematical model, researchers have shown that lengthy courtships evolved to allow women to weed out unreliable partners.

Prof Robert Seymour, of University College London, used a branch of maths called game theory to explore the dating rituals of men and women.

The findings mirror the advice given to generations of women by agony aunts, big sisters and close friends.


Saying no: Mathematicians have shown that 'better' partners are willing to date for a longer time before having sex

His model is based on the idea that women have the most to lose from any new relationship because they can end up with a baby fathered by an inappropriate - or even absent - father.

It assumes that courtship is a battle between the sexes - with both sides compromising on the point in the developing relationship where they have sex.

'Courtship in a number of animal species occurs over an extended period of time,' said Prof Seymour.

'Human courtship, for example, can involve a sequence of dinners, theatre trips and other outings lasting months or even years.

'One partner - often the male - may pay the greater part of the financial cost, but to both sexes there is a significant cost of time which could be spent on other productive activities. Why don't people and other animals speed things up to reduce these costs?

'The answer seems to be that longer courtship is a way for the female to acquire information about the male.

'By delaying mating, the female is able to reduce the chance that she will mate with a bad male.'

The model looks at a simplified courtship between a man and woman in a society without contraception.

In the model, the courtship ends when the man or women quits or the female accepts a male as a mate.

It also assumes that there are just two types of men - 'good' ones and 'bad' ones according to his willingness to be a good dad, and that the males get a 'positive pay-off' from mating with any female.

It also assumes that 'good men' will wait longer before having sex.

The model looked at every variation of courtship to find the best - and most likely - compromise for the man and the woman.

Because bad males have a greater tendency to quite the courtship game early, women can increase their chances of mating with a suitable man by delaying sex, the researchers found.

'A male's willingness to court for a long time is a signal that he is likely to be a good male,' said Prof Seymour who published the findings in the Journal of Theoretical Biology.

'Long courtship is a price paid for increasing the chance that mating, if it occurs, will be a harmonious match which benefits both sexes. This may help to explain the commonly held belief that a woman is best advised not to sleep with a man on a first date.'

The model does not work so well in a society where contraception removes much of the risk of becoming pregnant. It also ignores social and peer group pressures on men and women.

However Prof Seymour believes it helps explain how the extended courtship of humans may have evolved in prehistoric societies tens of thousands of years ago.

Source: http://www.dailymail.co.uk/sciencetech/article-1119424/The-mathematical-formula-proves-couples-NOT-sex-date.html