She has spent hours on her hair and make up, bought a new outfit¹ and done her nails. So perhaps it is only fair that her date should pay for dinner.

她花了好几个小时做头发、化妆，买了新衣服，还做了美甲，所以让她的约会对象付饭钱应该算是公平的吧。

Pretty women are less likely than plain Janes to offer to contribute towards the bill on a first date, research shows.

But they are not worried about the expense - it is likely to be because they believe their date should pay for the pleasure of being with them, according to researchers at St Andrews University.

The intriguing²（有趣的） finding comes from a study of 416 men and women who were asked to rate themselves for attractiveness, ahead of going on a series of hypothetical dates.

In each case, they were shown a picture of their ‘date’, told to imagine they had been for dinner together, and asked to decide who should pay for the meal.

They could decide to pay for the entire meal, nominate their date to pay or choose to split the bill.

The answers revealed that the good-looking women were less likely to want to contribute towards the costs. Handsome men were also reluctant to splash the cash.

Researcher Michael Stirrat said: ‘They quite literally³ bring more to the table, so they expect the other person to pick up the tab or expect to pay for the bill.’

Things, however, may change, if the man wants to impress.

The study, published in the journal Evolutionary⁴ Psychology⁵, showed that a man is more willing to pay for a good-looking woman.

Dr Stirrat said: ‘When a man offers to pay for the meal he is to some extent saying “I’m interested, I’d like a second date, I’d like to see you again”.’

But with women, the opposite is true. The study found that a woman expects a good-looking man to pay for her, perhaps as a way of making him invest in their future.

The researcher said: ‘When the woman lets the man pay for her, she is basically saying she’d like a second date.’

It also means that if a woman does insist on paying, or at least making a contribution, it may be a sign that the date hasn’t gone well.

Dr Stirrat said: ‘If he is less attractive, she’d rather split the bill（平均分摊费用） .’