One of the themes of my forthcoming novel, Secrets of the Pomegranate, is prejudice and the way we – as individuals and collectively – can be blinded, sometimes wilfully, by preconceptions about whole ‘categories’ of people. Equating Muslim with terrorist is one example.

My own preconceptions were brought home to me a year or two ago when I fell victim to thieves on a bus in my home town of Granada. The two neatly-dressed young women, working as a team but not visibly together, did not look like thieves. One of them was pregnant. (Why, I wondered later, should that make a difference?) If they had been male, of ‘dodgy’ appearance, I would have been more alert. Their tactics were – with hindsight – obvious, yet I ignored all the signs because these women didn’t fit the stereotypical image in my head. An irrational prejudice that cost me two days’ delay in my travel plans (I was on my way to the airport for a trip back to Britain), the price of an emergency passport plus a replacement for the 10-year one I had only recently renewed, about £150 in cash, a night’s accommodation in Málaga, a new flight – expensive because last-minute – and a huge amount of stress and wasted time.

I had given up my seat to the pregnant woman, who was distracting me with faces and sighs while her accomplice busied herself with my rucksack, which was not on my back but resting on top of my suitcase right under my eyes with my hands on it. Having checked there was nothing of value in the outside pocket, she somehow managed, in no more than a minute, to retrieve a small bum-bag from deep within the main compartment They were clever but not that clever. Various odd details had already made me suspicious, slightly nervous – but not of them. Only hours later did I piece together the sequence of events.

So what do thieves look like? Must they be male, shabbily dressed, not too young, nor too old? I was appalled to realise how much I had been influenced by a stereotype. But it also taught me a lesson, showing me how our preconceptions can rebound, to our own detriment. Some twenty years ago I was robbed of my purse on an underground platform in London. The man who brushed past me was middle-aged, dressed in a suit, carrying a briefcase. He didn’t look like a thief either.