The Sainsbury's Finishing School

A debate over the etiquette at supermarket checkouts has been sparked this week after a customer in Sainsbury's was refused service by an irate member of staff until she hung up her phone. It went a little bit like this:

Cashier stares at woman.

Woman asks if everything's okay.

Cashier says:  'I will not check your shopping out until you get off your mobile phone.'

Woman ends her call and says:  'Apologies, I didn't realise that it was Sainsbury's policy that you are unable to use your phone at the checkout'.

'Well you learn something new every day', came her reply.

I have to agree with David Mitchell on this - both women sound nauseatingly passive-aggressive, irrelevant of the debate behind it - which is whether it's okay to talk on the phone while being served. It isn't against the law, but neither is weeing in the shower - this doesn't mean it's okay.

Earlier this year I stood behind a woman in a shop who, on reaching the front of the queue, said into her mobile: "Can I ring you back in a minute? I'm just getting served". Depressingly, I was shocked enough to remember it months later, which proves how often I've seen the opposite happen.

The concept of mobile phones is brand new when you look at the time span of the human race, but this isn't a good enough excuse to warrant the behaviour we display towards them. Not only do we stay on them when being served in supermarkets, we shun real conversation for texting. We favour looking through Instagram to looking up at the world without a filter. We watch gigs through a screen.

Our phones are the automatic answer to having a moment to wait in a queue. If we're not careful, smart phones will eventually outwit us. Not because they're becoming cleverer, but because ten brain cells pop every time we sit on a train and scroll through Facebook for the entire journey. I don't think this debate has everything to do with phones, though.

I've often been annoyed by checkout cashiers who have failed to acknowledge me. People lacking manners lack manners whether it involves a phone or not. Supermarkets require inevitable exchange between staff and members of the public that bring out these tendencies. Most of us spend more time than we'd like shuffling through supermarkets isles, and life sometimes requires important phone calls. The small part of me that isn't cynical thinks we (and this woman) should be forgiven if the two sometimes overlap.

Perhaps the rude customer in question was just complaining about the price of tuna to her friend on the phone, to which I say: fair enough.