What do writers tell themselves when they get a bad review? As a literary critic for the past 13 years, it's not a question I've liked to ponder too much. Especially when the answer isn't likely to be, "I take on board every sensible, accurate word that perceptive reviewer said ... "

But recently, the tables have been turned. I'm gamekeeper turned poacher, and have felt for the first time the full force of the Bad Review. My first non-fiction book has managed to attract the attention of no fewer than 27 reviewers and most of that number have been, I'm relieved to say, extremely positive. A few were mixed, and a couple too silly to take seriously. But a small number – four, to be exact – were downright hostile.

Not wanting to run and hide – actually, I was hoping for some comfort – I posted the negative reviews on Facebook. My writer friends (yes, I have some) duly obliged. "She's just a wannabe writer," said one, of the author of a particularly cutting example. "Those who can, do; those who can't, criticise," said another. "It's personal – she's probably getting back at you for a bad review you've written about someone she knows," said a third.

Were they kidding? Is this really what writers think of critics? That they spend their time typing up vicious reviews of authors because they're jealous, or to defend their friends? Or because it's the closest their talentless, deluded minds can get to literary immortality? The thing is, having been on the "other side" for so long, I know better. I know that the majority of reviews are not personal, and are not written by people who can't master the craft hitting out at those who can.

But you don't have to be a critic to know this. A cursory glance at the majority of broadsheet books pages would show that most reviewers are not "wannabes" – most of them are also published writers. Gone are the days when the critic was in one corner and the author in the other, two different species eyeballing each other before the fight to the finish. It's a strange hybrid, this author-critic creature. I can't think of another art form where the "practitioner" and the critic overlap like this. Where are the dancers who are also dance critics? Where are the playwrights who also write theatre reviews? Where are musicians who critique bands? Only in literature does this overlap occur, although writers, it would seem, would prefer to believe that it doesn't. Writers would prefer to believe that critics are separate, and that their separation means they're the enemy, and out to get them.

The irony is that writers are generally meaner to other writers than critics are. Few critics have anything to gain by penning a bad review. (Writers like to believe Michiko Kakutani achieved the status she has by writing bad reviews of the big boys, but if that were true, we'd all be doing it). Writers, on the other hand, have everything to gain, and that's when the hybrid crossover becomes a problem. After all, it was a writer (a historian, in fact), Orlando Figes, who gave bad reviews to his rivals on Amazon, then pretended he hadn't. It was Philip Kerr who wrote a bad review of Allan Massie's latest book on Amazon, after Massie had criticised Kerr's last two books. It's writers who have personal scores to settle; who drop their professional guard and let rip. Critics, by and large, (there will always be the odd exception) say what they think of a book. If they say they don't like it, that usually means they don't like it, not that they really spend their time waiting for the chance to hit back at a bestselling author for the luxury Tuscan villa he owns and they'll never have, or because their homes are filled with ceiling-high rejection slips from publishers for their own hopeless literary efforts.

No, those "comforting" words from writer friends couldn't comfort me at all. All I could do was shrug my shoulders and think, four critics didn't like my book but over 20 of them did, and take strength in numbers. And wait for the chance, of course, to post that anonymous poisonous review on Amazon some time soon ...