OTHER people's shopping is a great source of interest - what else is there to do in the checkout queue but watch what's going on to the moving belt from the trolley in front?

Why there are a dozen cans of beans sailing down towards the scanner, but nothing else to indicate the presence of children or teenagers, or why one household needs three packs of sticky plasters, just take their place among life's little mysteries.

We've all done it to pass the time, but the Meat and Livestock Commission has had its spies out in five of the UK's top "multiple grocers" (supermarkets to you and me) with much more serious intent.

The commission has been cultivating a decision tree. The roots and branches are how and why we decide to buy meat products and the fruit is insight.

There's a paragraph or two of "insight" on most pages of The Shopping Decision Tree report to help those who design the displays and those who set them out to - no surprise here - sell us more meat.

If you shop for a carnivorous household, see if you fit the MLC's pattern.

Two-thirds of you won't take a written shopping list. As one of the remaining third who never fails to write one (though I frequently leave it on the kitchen table) that intrigues me. Have you all got fantastic memories or do you end up with three boxes of cornflakes in the cupboard but no spare tea bags?

You won't want to be without four "everyday" items: bacon, sausage, mince and sliced meat. Count most of us in on that one. I've generally got the first three in the freezer as the result of special offers, or in the fridge, and the fourth figures somewhere in the week.

You like mince because it's easy and very versatile (cottage pie, plate pie, spag bol, mince an' tatties, home-made burgers) and, like sausages and bacon, there's no real substitute if what you want isn't in stock. The "insight" here implies that good availability in a neatly categorised display is most important to you.

Bangers and bacon are the great stand-by; ingredients of the all-day breakfast and, like mince, if you can't see what you want, you're likely to go elsewhere rather than pick an alternative. On the other hand, a wide choice of sliced meats means you're happy to pick a substitute.

You buy joints, chops and steaks for "key occasions", meals planned ahead, but with the actual decision on what to buy often taken in the store. Price is important, money off offers are too, but you're much more willing to substitute another cut for the one you first thought of. The insightful store has an eye-catching display for joints and ideas for making chops and steaks appeal to children.

Chilled ready meals are for "key occasions" too, for spoiling yourself or for saving time. They're often impulse buys. Insight says the product must live up to the promise on the packet. Is insight an optimist?

Poultry, not surprisingly, falls between everyday and key occasions. Six out of ten of you know you want poultry before you go into the store. It's often on special offer, you look keenly at the price and, if you can't see what you want, will buy another meat, even though you think of poultry as healthy. On the other hand, poultry is readily bought if something else isn't available.

Yes, I reckon they've got it about right. It all fits in with the meat I buy, except in one vital factor, and those of you who share that are probably bursting to tell me to include you out of all this.

We never buy meat in a supermarket. We go to independent family butchers so we weren't part of the decision tree. That's maybe because we don't have to make our decisions alone; there's a bit of chat, a bit of advice, maybe an MLC recipe leaflet and (sometimes) a bit of jollying along.

I suspect we're more likely to be buying British, too