The age-old question of why the chicken crossed the road has finally been answered: it wanted to reach the comfort and safety of the battery farm on the other side. According to a study by the animal behaviourist Jeff Downing, of Sydney University, it isn’t battery cages that leave chickens feeling stressed but the wide open spaces of free-range farms.

Dr Downing studied levels of the hormone corticosterone, released when an animal is in a stressful situation, in both battery and free-range birds and concluded that, contrary to popular opinion, the former are no less happy than the latter. He also observed that hens bred indoors, away from the threat of predators, do not become startled like outdoor hens every time a shadow falls upon them.

I can’t say I am surprised by Dr Downing’s findings. Occasionally I walk past a free-range chicken farm in Norfolk and have always been amazed by how few of these liberated birds actually bother to venture out of doors: most choose to stay crammed in their sheds.

It is the same with pigs. Pig farms have been forced at great expense under animal welfare laws to reconfigure their pens to allow pigs to wander around, but when I visited a farm to see the animals enjoy their freedom I found them slumped on the ground: the removal of the pens, the farmer told me, had made no difference to their behaviour at all.

I don’t know where the notion that battery-farming is cruel came from, but it certainly didn’t arise from asking the birds. Our preference for free-range eggs – which now account for 37 per cent of all those consumed in the UK – is just aesthetic: it comforts us to think, as we crack open an egg, that the chicken who laid it came from some tumbledown farmyard.

If it gives us pleasure to buy food produced in a more traditional manner, that is one thing. But to assume that the kind of farming that suits our environmental consciences must necessarily be in the best interests of chickens is deeply patronising to the poultry community. How can we possibly know what is going through the mind of a hen? All I know is that if chickens are even slightly like humans the last thing they would want to do, to use the fashionable expression from animal welfare regulations, is to “express natural behaviour”. How many of us, given the choice between a life of foraging for nuts and berries, stark naked in the rain, and living in a small, centrally heated flat with a fridge full of food, would choose the former?

If we prefer the lazy life, why assume that farm animals are different? I doubt whether we will ever get to the bottom of animal psychology, but I suspect we could get closer to satisfying the desires of a chicken not by casting it outdoors but by plying it with junk food, beer and a live feed from Big Brother.

Times Recommends

• It’s not just about Iraq, it’s about Blair’s style
• You can’t rank hospitals like football teams
• Minarets are not an essential part of Islam