Every summer and every Christmas, the weekend broadsheets publish some sort of holiday reading list, calling in the favours of the famous to give their views on the best books of the year. For book-lovers, the lists do several important things. First, they serve to inform the non-publishing world of who in publishing is - either privately or professionally - sleeping with who, who hopes to sleep with who in the near future, and who has recently been relegated to a bitter celibacy.

Second, they act as excellent absentee guides for the better-read burglar. Third, they inform the general reader which Wittgenstein-citing pillock they should kick sand at. And fourth, they act as excellent involuntary indicators of male/female reading tastes.

It remains peculiarly difficult to alter the fact that women will read a book by any author - male or female - but men tend only to read books by other men. Of the 56 books suggested by the male celebs in the Observer's most recent summer reading guide, only six were by women. Until fairly recently, you could have argued that there just weren't enough female authors to go round. Return to the classics, and the argument counts for something; for every slim Jane Austen, there are always a hundred overweight Thackerays. But part of the point of the summer reading lists is to promote the most recently published books, and - in the year when a children's book by a female writer managed to outsell every other book published by several squillion percent - you'd be hard pushed to argue that women are still underrepresented in the bookshops.

So what is this subtle literary separatism that keeps the boys so far from the girls? Conduct even the most fallible of straw polls, and the same fact emerges: unless compelled towards Eliot or Brönte or Woolf by the school syllabus, even the best-read men will not have managed more than a couple of token well-intentioned efforts. Even among more recent offerings, only those books by women which have been most confidently hyped and soundly endorsed (preferably by other men) will appear on the general male radar.

But does the same happen in reverse? Yes, probably. For women, the more ostentatiously macho writers - Hemingway, Pynchon, Mailer - exude a clubbish exclusivity which can seem either dull or incomprehensible, or both. Life is just too short to accommodate Big American Books about baseball and masturbation. On the other hand, there comes a point where most women have to make a conscious decision between reading Sylvia Plath forever, or moving on to something which doesn't make them want to stick their head in the oven - even if it does happen to include cricket or God, or sprockets.

There are other small discrepancies between male and female reading habits. It is a truth universally acknowledged that, while male writers are obsessed with the first sentences of their books, female writers tend to be much more bothered by all the ones that come afterwards, and are usually incapable of remembering any first lines at all except for the one beginning with "It is a truth universally acknowledged ..."

Men like puns; women prefer something resembling humour. ("Not just any puns," objected one male friend, "only mine.") Men like books with "Sinister Deadly Ultimatum" or "Lingering Disembowelment" in the title. Women like books with "Diet" or "Men - Sad Primitive Emotional Nematodes?" in the title. According to the organisation Book Marketing Ltd, women buy more books than men, but men spend more money on the books they do buy. Men are capable of tolerating rock biographies, books which consist entirely of lists, and books with characters called "Swyddffynnon the Elfish". Women can put up with whole books consisting of pictures.

So are any of these disparities really a cause for outrage? Yes, it probably is a disgrace that men still maintain such an intractable prejudice against writing by women, but not when you consider that more than half the British population - male or female - consider themselves to be "light or nonexistent" bookbuyers. Or when you realise that a third or so of the British population never read at all. And that, however reluctantly, it is necessary to concede that even bad puns and sprockets are better than nothing at all.