One of the unexpected consequences of publishing a novel is that people suddenly seem willing to pay to hear me speak. Sometimes I don't even have to invent anything new to say, I simply get to read out loud the words I've already written on the page and everyone listens politely and then claps, which seems as good a way as any to make a living.

I was at just such a reading last week in Ireland in front of a nice, respectable audience – the kind of people you can imagine advertising insurance plans for the elderly on TV – and I was about two-thirds of the way through when I realised, to my horror, that the passage I had chosen to read included the word "penis" in the final paragraph.

In a book of 100,000 words, this was the single mention of genitalia. Why on earth had I not noticed it before? But it was too late. On I read, the offending word flashing up at me like a Soho sex-shop sign. As the sentence got closer and closer, the word became bigger and bigger until it was burning itself into my mental synapses.

In the end, I skipped over it. Words spoken out loud sound far stronger than they do on the page – especially rude ones. Perhaps, I thought to myself afterwards, it's a kind of anti-Tourette's, where I can't bring myself to swear in public but can shout inoffensive phrases in social settings. So if you happen to pass a woman on the street screaming: "Nice weather today, isn't it!", that's probably me.

In the taxi on the way back to the airport the following morning, I fell into conversation with the driver, who asked me what my novel was about. I sketched the plot for him briefly – the tensions between a family of three, the betrayals and compromises of their intertwined lives.

He listened attentively, then said: "Ah yes, that sounds like the kind of thing a woman would write."

I asked him what he meant.

"Well now, no offence, but women like to write about… small things."

I should point out here that at no stage had I mentioned the penis. It appeared the taxi driver simply believed that female writers concentrated on the everyday, domestic sphere whereas male authors tackled Grand Themes.

It is a familiar argument. There is a presumption that if a woman writes a sprawling family saga it betrays a lack of imagination, as though she has taken the material of her own petty life and applied to it the thin varnish of fiction. But if a man does the same, he is somehow writing about the human condition.

I've lost count of the number of times readers or reviewers have assumed my novel is autobiographical. Similarly, Nora Ephron's bestselling novel Heartburn, which charts the course of a failing marriage, was almost universally assumed to be a thinly disguised version of her marriage when it was published in 1983. Referring to this a few years ago, Ephron pointed out: "Philip Roth and John Updike picked away at the carcasses of their early marriages in book after book, but to the best of my knowledge they were never hit with the 'thinly disguised' thing."

And whenever brilliant writers such as Anne Tyler or Joanna Trollope or Maggie O'Farrell publish their latest novel, there will always be someone somewhere who claims it is "aimed squarely at the women's magazine market". I can't recall Jonathan Franzen being told his writing is "aimed squarely at the readers of Men's Health", nor do I see it as a disadvantage when a book is seen as accessible. Shouldn't literature be about communication? Or should we all be aiming to craft impenetrably postmodern prose no one wants to read?

I wish I'd said all of this to the taxi driver. Instead, wanting to avoid unnecessary conflict, I changed the subject.

Typical woman.