Melbourne: A new study has shown that attractive couples are more likely to have daughters as compared to plainer parents who tend to have sons.
Satoshi Kanazawa, an evolutionary psychologist at the London School of Economics and author of `Ten Politically Incorrect Truths about Human Nature`, also argues that beauty is a stronger predictor of reproductive success for women than for men.
17,000 babies born in Britain in March 1958 were followed up at various points in their lives, including at age seven, when they were rated as attractive or unattractive by their teachers, and at 45, when they were asked to record the age and sex of their children.
Kanazawa found that while the children who were rated as attractive – 84% of the sample – were equally likely to have a son or a daughter as their first child, the unattractive children were more likely to have sons.
Children who were labelled ugly when they were aged seven had a 56% chance of having a boy.
"Physical attractiveness is one of the strongest determinants of women`s mate value," the Courier Mail quoted Kanazawa as saying.
He believes that the trend could be driven by the relative value of attractiveness in men and women. Men tend to rate attractiveness in women as important when seeking both long-term relationships and casual affairs.
However, women tend to rate physical attractiveness highly only for short-term relationships, ranking traits such as wealth and status as more important in the long term.
The study is to be published in the journal Reproductive Sciences.
David Spiegelhalter, a senior biostatistician at the University of Cambridge, said he was sceptical about the figures.
"We only get the clever analysis and are not told the raw data – the actual proportions of girls born to the beautiful and the ugly," he said. "As a professor of statistical jiggery-pokery, I know odd things can happen when adjusting for, say, social class."