FATHERS WILL DO anything for their little princesses. They turn a blind eye as the house becomes a palace of pink fluff. Later on they play a pivotal role in their daughters’ social development — that of chauffeur.

Dads will even, we learnt this week, shift political allegiance for their daughters. Andrew Oswald, from Warwick University, and Nattavudh Powdthavee, of the Institute of Education at London University, have discovered that how parents vote is linked to the gender of their children. The more daughters there are in a household, the more likely the parents are to vote Labour or Liberal Democrat. In an unpublished paper that has been submitted to an economics journal, the pair declare: “This paper provides evidence that daughters make people more left wing. Having sons, by contrast, makes them more right wing.” The academics go on to speculate that left-wing families become so through a predominance of females down successive generations.

The researchers have been accused of propagating gender stereotypes, and of perpetuating the idea that women go in for softer politics than men. The feminist ire, however, is misdirected. Some of the most exciting scientific research points to a similar, intuitive conclusion — that, on the whole, men and women think and behave differently. One emerging theory of autism — a condition that affects three times as many men than women — is that autistic behaviours are extreme versions of typical male traits. So, for example, a preoccupation with objects becomes an obsession. Psychopaths, whose lack of a conscience is linked very strongly to brain abnormalities, are also predominantly male. While we are busy dismantling the gender barriers that sprang up historically through sexism, contemporary research is erecting new ones under our very noses.

Professor Oswald and Dr Powdthavee drew their data from the British Household Panel Survey, which has monitored 10,000 adults in 5,500 households each year since 1991 and is regarded as an accurate tracker of social and economic change. Among parents with two children who voted for the Left (Labour or Lib Dem), the mean number of daughters was higher than the mean number of sons. The same applied to parents with three or four children. Of those parents with three sons and no daughters, 67 per cent voted Left. In households with three daughters and no sons, the figure was 77 per cent.

But it was the “switchers” who provided the most compelling evidence. By examining declared voting preferences for the period 1991 to 2004, Professor Oswald and Dr Powdthavee found that 539 people switched from Left to Right, and 802 switched from Right to Left. The most significant difference between these two groups of switchers? The voters who swung from Right to Left had borne, on average, more daughters.

Professor Oswald, the father of two daughters, sat on the results for three months. He decided to release them this week, after finding the same pattern in German households. For every daughter a German has, he is 2.5 per cent more likely to vote for the SPD, the largest party of the Left. The link holds true even when parental age, income and education are taken into account, and Professor Oswald is certain it is causal. Since voting patterns cannot determine the gender of children, he says, the children’s gender must be influencing parental voting pattern.

But how and why? He frames his theory in utilitarian terms: because women tend to be more group-oriented, and to be paid less, we may expect them to favour a political system that taxes heavily and spends the taxes on communal improvements, such as crèches or police patrols. Women benefit from such policies without bearing a high tax burden because they are on low incomes. Parents of daughters are subconsciously aware that such policies favour women, and thus feel more inclined towards them.

But we still need to explain why parents would vote for something that benefits their offspring rather than themselves. Here Professor Oswald invokes Darwinian theory, which is that people make decisions that are likely to benefit their children. When children prosper, their chances of reproducing also flourish, and the genetic line is more likely to be continued. He believes that a switch in voter behaviour is a “subconscious nod” in this direction. While everyone assumed that parents moulded the political allegiances of their offspring, he says, the idea that one’s priorities change after parenthood is perfectly intuitive.

Professor Oswald was berated on the radio this week by a (female) journalist not only for reinforcing gender stereotypes but also for dreaming up a theory and then finding the facts to fit. It is a naive and futile accusation. The academics asked no leading questions, instead they analysed one of the most comprehensive sets of data available to social scientists. They kept quiet until they found the same trend in another data set. And that is the marvellous thing about cold, hard numbers: you can’t argue with a respectable analysis, especially when it throws up the same result twice.

The journalist went on to decry the preponderance of pink clothes for baby girls, and announced that she had bought tractors rather than dolls for her own infant daughter. She will find that gender is not so easily subverted, especially in the light of behavioural research that shows boys will be boys and girls will be girls. Since the research also suggests a shrinking role for parental influence on a child’s behaviour, she should prepare for the pink fluff.

Times Recommends

• Fragility always gets my sympathy vote
• Double it and you get the real jobless total
• Has al-Megrahi paid his council tax?