Apparently, it’s a bad habit to cross your legs. It twists your pelvis, elevates your blood pressure and results in lower back pain. The other day someone explained the perils of crossing your legs, detailing the structure of the hominid skeleton. At one point they pulled out their masterstroke argument: “Gorillas don’t cross their knees.”

Later on, I wondered: is that right? I fell into a pensive mood. I would have crossed my knees, supercharging my thinking, except I now knew how dangerous that would be. I fantasised about seeing a gorilla with their knees crossed, just sitting there, flipping through a copy of the newspaper, which is what I often do when I have my legs crossed.

I’d also enjoy seeing a monkey bite their nails or a dolphin scratch their crotch. Human beings have so many bad habits, I’d like to think we’re not the only ones to have parts of ourselves in need of reform.

Dogs, after all, have plenty of bad habits. Some of their habits are even worse than those of humans. You won’t find me chewing on other people’s shoes or barking at children just because they’ve decided to walk past our front door. I don’t rush my food. I rarely shed fur. I have never knowingly bitten a postman.

Cats are even worse. I may cross my legs but, compared to a cat, I’m relatively well-behaved. I don’t cough up fur balls. I don’t scratch the furniture. I have only once vomited on a bed, something that for a cat is so commonplace an activity as to be hardly worth recording.

Then again, cats rarely drink three beers too many, yell at politicians on the TV, or eat a whole packet of peanuts just before bedtime, so maybe we are even.

By the time you get to my age, what’s called your ‘personality’ is just an accretion of bad habits.

Emus are total bastards. I know they are on the country’s coat of arms – a privilege they owe to the fact that, alongside the kangaroo, they are unable to go backwards. This, it seems to me, is making a positive out of a negative. It also ignores the fact that if you get too close to them, they’ll bite you. The coat of arms should, at the very least, come with some sort of warning. Put it in Latin if you like: “Hic avis mordet.”

By the time you get to my age, what’s called your “personality” is just an accretion of bad habits. Crossing your legs is the least of them. A personality that, in your twenties, was described as “exuberant and carefree” is now “talks too much and refuses to use deodorant”.

Likewise, “thoughtful” somehow becomes “dreary”. “Caring”, even worse, becomes “interfering”. If we all triumphed over our bad habits, I sometimes wonder what would be left? “Oh, that’s Richard. He just sits there.”

It could be worse. We could be mice. Our household experienced a mouse infestation a month after the neighbour decided to get chickens. The mice lacked all etiquette. First, they chewed through all the food in the pantry, then they cavorted on the kitchen benchtops. Some nights, once we were asleep, they had an orgy on the couch. It was like living in a student share house in 1983. Every morning, I’d have to apply a heavy application of Domestos. It was even worse when I was dealing with the mice.

Humans, it’s true, are the champions when it comes to bad habits. Some bad habits are small, but some are big. Climate change is nothing more than the bad habit of selfishness, expressed on a global scale. World poverty? It’s just an ill-mannered refusal to share. Did no one have parents to teach them how to behave?

All the same, is the animal kingdom an appropriate yardstick against which to measure ourselves? Is it fair to use the gorilla as a template for human behaviour? Sure, gorillas don’t cross their knees, hurrah for them, but they also tend to walk on their knuckles and to roar. If I did that in Colesworth, they’d call in the authorities. And if gorillas travelled on trains, lolling on their large backsides, they’d be accused of manspreading. “Can’t you at least cross your legs?” would be the chorus heard up and down the carriage.

Meanwhile, I sit and fret. I’ve spent so many decades crossing my legs, I now find it impossible to stop. Ditto: biting my nails, jiggling my right leg, and reading the best bits of the newspaper aloud to Jocasta, a minute-and-a-half before she was about to read the paper for herself.

Could I at least cross my ankles? Apparently not. That’s dangerous too. And so I sit, my pelvis perfectly aligned. My blood pressure is fine, and I have no pain in my lower back. All the same, I have an urge to beat my chest, roar aggressively and then assemble a harem of six females.

Which, presumably, is the explanation for all that gorilla bad behaviour. Someone told them they weren’t allowed to cross their legs. Poor saps. I say: embrace your bad habits. It may be all we have left.