WHY DO women earn less than men? Why are there fewer women than men at the top of most professions? The answer, according to a new book, is not discrimination at work, nor even outdated working practices, it is biology, pure and simple. According to Kingsley Browne, professor of law at Wayne State University, Michigan, attempts by governments to remedy the earnings gap, or to tackle the "glass ceiling" which keeps women out of top jobs, are pointless. Most women, he claims, do badly at work because our temperament isn't suited to it.

Sounds familiar? Of course it is. Browne's book - Divided Labours. An Evolutionary View of Women at Work - is published in Britain later this month, but there is nothing new about his views. "Many of the greatest human achievements have been possible only through the kind of single- minded devotion and willingness to take risks that men disproportionately display," he suggests. While his explanation is "scientific", his claims about the differences between men and woman are an uncanny echo of the Rev Thomas Gisborne, addressing the same subject in a book published in 1797.

Law, politics and commercial enterprises, according to Gisborne, "demand the efforts of a mind endued with the powers of close and comprehensive reasoning, and of intense and continued application, in a degree in which they are not requisite for the discharge of the customary offices of female duty". Male minds, in other words, so there was no point in trying to improve women's performance through education. Gisborne lived, as we do, in a period of fin-de-siecle gender anxiety and was an early exponent of what became known in the Victorian period as the doctrine of "separate spheres".

This subject inspired hundreds of tracts in the 19th century and I sometimes wonder whether today's neo-Darwinians, enthusiastically arguing the case that biology is destiny, realise how closely their arguments mimic those of the Victorian clerics whom Darwin himself did so much to challenge. I also wonder whether people such as Kingsley Browne are interested in what millions of women really want, as opposed to handing down a prescription for working life which favours successful men and employers who are happy to exploit cheap female labour.

At a moment when Opportunity 2000 is predicting that women will soon make up 51 per cent of the workforce in Britain, it seems perverse to tell us we will never feel comfortable at work, rather than looking for ways in which employment practices could be changed to accommodate our needs. Men do this all the time, without calling into question their commitment to work. Last week, when electricians employed on the Jubilee line extension in London mounted a court challenge to the long hours they are expected to put in, no one suggested they were biologically maladapted to the workplace - just that they were fed up with working more than 60 hours a week. If Kingsley Browne is genuinely convinced that equal pay and flexible hours wouldn't help working women get greater job satisfaction, why is he so opposed to making the experiment?

A LESS palatable explanation for women's unhappiness at work is that offices and factories are not always friendly environments for female employees. Last month, a 45-year-old computer operator won her claim for unfair dismissal after an Exeter-based company which makes greeting cards sacked her for wearing "provocative clothing". The tribunal heard she had been described as "mutton dressed as lamb". A series of industrial tribunals involving the police - another began last week - have heard allegations from women officers about taunts from colleagues about their sexuality.

But it would be unduly optimistic to imagine that these occurrences are confined to traditionally male professions. I have just written to the producers of a BBC Radio 4 programme, Room for Improvement, explaining why I am no longer prepared to take part. After recording one of the programmes, I went for a drink with a producer and the presenter, Laurie Taylor. During a conversation about the programme, Taylor mentioned a male guest and remarked: "Of course he thinks you're a lesbian. He knows you don't fancy him and he thinks you're a lesbian."

As it happens, I don't think there's anything wrong with being a lesbian, but I do object to having inappropriate labels stuck on me - and to hearing the word used as the worst insult a man can dream up. Nor was I impressed by Taylor's defence that "men feel a little bit beleaguered" these days, given that I am outnumbered by men on almost every radio or TV programme I appear on. Obviously I gave as good as I got, suggesting to Taylor that he was suffering from - how can I put it in a family newspaper? - the male equivalent of penis envy. But working women can hardly be expected to feel at ease while even a minority of their male colleagues are prepared to behave in such a manner.