The War of the Sexes: How Conflict and Cooperation have Shaped Men and Women from Prehistory to the Present

  • Paul Seabright
Princeton University Press: 2012. 256 pp. $24.95, £16.95 9780691133010 | ISBN: 978-0-6911-3301-0

My grandmother was a cleaner; my mother was a medical doctor. That is a single example of how, in the course of a few decades, women's educational and professional opportunities have increased vastly. As of 2010, about 60% of US women were in the workforce, making up nearly half of all workers; the picture for most other developed nations is similar. Women can do just about any job, and in many countries overt discrimination is illegal.

Despite a rise in professional opportunities for women, many are still paid less than men. Credit: W. WEST/AFP/GETTY

But other statistics tell a different story. In 2010, women made up just 1 in 7 company board members and 1 in 40 chief executives of Fortune 500 companies. And women still earn less than men for the same jobs. In the United States and Britain, a female lawyer earns, on average, about three-quarters of her male counterpart's salary. For newly qualified US medical doctors, the pay gap is widening: 17% in 2008, up from 12.5% a decade before.

In The War of the Sexes, Paul Seabright, an economist working at his subject's boundary with evolutionary biology, argues that human evolution can help to explain the inequities of today's white-collar, Western workplace. It is a story well worth hearing, but it is incomplete — partly because there is little decisive evidence for what causes gender gaps in employment, and partly because of some curious authorial choices.

The first half is an excellent primer on why males and females have evolutionary cause to behave in different ways. Sperm, Seabright explains, are cheap and plentiful; eggs, the opposite. This tends to make females choosy about their mates, and males less so. So males must compete for female attention by fighting among themselves, or by seducing prospective mates with advertisements of quality, such as gifts of food. Such differences in sexual supply and demand create conflicts of interest and incentives for deceit.

Paradoxically, our cooperative natures exacerbate these conflicts. Collaboration in child-rearing is key in humans because of the long childhood needed to grow a big brain. Men can provide resources such as meat, but in return, fathers and husbands have sought to control what (or, crudely but more accurately, who) women did.

In the second half of the book, Seabright investigates how such conflicts might explain the dearth of women at the top of the career ladder. Using evidence drawn mostly from the upper echelons of business, Seabright suggests two causes of inequality.

First, anyone who takes a career break suffers for it. Even years after returning to work, he or she can expect to be paid less than a colleague who stayed put. So, Seabright argues in a claim that is likely to be controversial, there is no systematic discrimination against women here — it is just that they tend to sacrifice office-time for child care. The cost of this, he says, results from a “signalling trap”: to get to the top, an employee must work all hours, not because it gets the job done, but because bosses take such behaviour as a sign of quality and commitment. Like a peacock investing in a huge tail to show off his good genes at the cost of his flying ability, this is hugely inefficient; but anyone who opts out unilaterally pays a disproportionate cost.

Second, Seabright argues that women are disadvantaged by networking behaviour. Each sex, for example, prefers to network with its own kind. In a male-led workplace, therefore, men's social and professional networks tend to overlap more than women's, so women are less likely to find professional opportunities. The evidence for this is more preliminary than that for the effect of career breaks, but it points in the right direction. If you look in executive directors' pay packets, for example, women seem to benefit less than men from being well connected.

Throughout the book, Seabright is terrific company — entertaining and convincing. In a debate in which both sides tend to fit the evidence to their ideology, he lets the data take the lead. His recommendations for a more equal workplace, such as compulsory sex balance on job shortlists and mandatory paternity leave, are sensible and modest. Yet as a whole, The War of the Sexes doesn't quite hang together.

The first half shows that natural selection has given men and women different priorities, and so different strategies. But I struggled to make the leap from the economics of sex to the economics of work, including the modern pay gap. I would have liked to see a chapter stopping off midway between prehistory and the present, to look at how developments such as agriculture affected men and women. As Seabright notes, the biological similarities between the sexes show that women's “subordinate and dependent” state must be a relatively recent development — in which case, it seems odd to rely so heavily on the distant past.

In particular, the missing 10,000 years leave Seabright nowhere to tackle sexism and bullying. He assumes that people are rational and well-meaning. There is little discussion of cultural barriers to equality, such as male bosses' desire to keep women subordinate and dependent even if it costs them money. This is where those at the sharp end of the problem lay the blame: last month, a survey of women in UK banking found that three-quarters think that the biggest hurdle to equality is the attitude of senior male managers.

If this were a book by a science writer, I would no doubt be moaning that it sought to explain all of human life by shoehorning it into one grand idea. Because it is a book by an academic, I'm moaning that it under-coheres, that the circumspection and caveats impede its argument. This is a dispatch from a field in its infancy, and the gaps in its thesis reflect the holes in our knowledge. But with people such as Seabright working to fill them, we can at least be optimistic that we will eventually understand what causes inequality, if perhaps less positive that we can fix it.