Despite our best efforts, prejudices can sometimes be difficult to overcome.

I am walking through Bradford and there is a young homeless man sitting cross-legged with his back to a wall, an empty takeaway coffee cup in his lap. He is thin and bony and his clothes are shabby. He doesn’t ask anyone for money, just sits there.

My first instinct is to sort of veer away as though I’m going to cross the road, while I pat my pocket for change. I pull out a few coins. It isn’t a lot and I dither for a moment, wondering if it looks too paltry, before changing course and dropping them in his cup and walking on.

Later the same day I am coming up to him again, not veering away because I have my “I’ve already donated” face on. Just behind me and to my side are three men. They are being fairly loud, slightly lairy with each other. One is a big bloke with a shaved head, another is wearing a tracksuit. My danger radar kicks in, the spider-sense that tells you that if you said the wrong thing or looked at them the wrong way, especially if this was several hours later and beer had been drunk, then things might get a bit nasty.

A young woman in a short skirt walks towards us and the three men mutter things that I can’t quite catch and all laugh. We are coming up to the homeless guy, me and the three men. From the corner of my eye I sense them slowing, looking towards him.

I slow my pace down as well, but they cut behind me. I glance at the homeless man. He is looking straight ahead, his eyes fixed on a point on the pavement, perhaps his danger radar – and, let’s face it, he probably has a more finely-tuned one than me, living rough and begging – is kicking in as well.

I walk several steps past him and slow, and stop, turning around. I’m not sure what is going to happen, but I can see the three men approaching the homeless guy. He continues to stare straight ahead.

I wonder what I’m planning to do. Other people hurry past. What if they start to have a go at him? What am I supposed to do? I have vague notions of lowering my voice a couple of octaves, telling them to leave it, move on. This, I consider, will likely get me a kicking as well, should such a thing be about to occur. But it’s too late, I’ve already stopped and turned round. Either I’m going to witness something horrible and stand mutely by and watch, or I’m going to have to get involved. I feel a rush of blood to my head.

The big man with the shaved head leans forward, a cigarette in his mouth. Then he drops a handful of change – more than I did – into the homeless guy’s cup and gives him a friendly smile.

The three men walk on, chatting.

Prejudices. Despite our best efforts, they can be difficult to overcome, sometimes.