I am gradually, but remorselessly, being pushed out of the marital bedroom. The presence of six cats, four of them so small as to be easily squashed by a clumsy male foot, is only the start of it. My wife seems to have had her laptop computer grafted on to the end of her fingertips, so it is always with her and always switched on, which makes it hard for me to sleep, or gain her uninterrupted attention, or any sort of attention at all. It is her real partner in life now, and that is a fact I have to face.

Furthermore, my wife – understandably – dislikes my snoring. Which is not unfair. Once, when I was sleeping in a tent on the pavement outside my local library in order to try to prevent it being closed by the council, a passerby asked another volunteer if there was an angry dog inside the tent. That is the general sonic tenor of the night noises I make.

My wife is constantly stealing the bedcovers while simultaneously accusing me of doing the same. She is a light sleeper. If I get up in the night to take a piss, she usually complains, which makes me feel guilty. Her hands and feet are horribly cold and she always tries to warm them up on my bare skin. And she often turns the light on when she comes to bed (she usually goes after me) on the pretext of looking for something or other. Usually her laptop.

This technological aspect is a big part of what I suspect is not only a personal but also a societal sleep crisis – people have long had rows about whether they should watch TV in bed, but now it's about texting and emailing and tweeting after hours. There's a lot going on in the bedroom, just not what used to go on when we were first married.

I love sleep, but I'm really not getting enough of it – or not enough of good enough quality. I know this because although I probably get at least eight hours a night, I am still tired come the afternoon and I usually take a nap.

It has been occurring to me of late: why sleep together at all? Why not follow the Queen and Prince Philip's way and keep a safe distance? Sleeping alone in a bed – on the rare occasions I manage to do it – is unquestionably marvellous. All that space and silence and non-wifeness. It's like peace.

There is a lot of evidence that sleeping apart is gathering popularity – at least in America, who the British tend to follow closely in terms of social trends. There, the National Association of Home Builders says it's expects 60% of new homes to have dual master bedrooms by 2015. If this is anything like a guide to how many couples are sleeping together, then a trend is gathering momentum.

One 2005 American survey found that nearly one in four couples sleep in separate beds – mainly for the obvious reason that it gives them a better night's sleep. You might think that trading intimacy for 40 winks is a devil's bargain, suitable only for those whose marriages are heading for the rocks, but it's not necessarily that simple. Getting enough sleep is important for general health.

A survey of 70,000 women aged over 16, published in 2005, showed that women who slept five or fewer hours a night were a third more likely to put on at least 33lb than sound sleepers. That's a big difference. So it appears that sleeping together – as it tends to result in disturbed sleep – makes you fat. The scientific explanation for this is that after just a few days of sleep restriction, the hormones that control appetite cause people to be hungrier. So women who sleep less might eat more.

The result of this weight effect on men is not known, which unfortunately deprives me of an excuse for my muffin tops. However, it does help explain why I can't remember people's names or get my birthday dates mixed up because studies at the University of Vienna in 2006 showed that sharing a bed with a partner, for men specifically, reduces brain power. They performed worse in cognitive tests than when they slept alone. Again, this was due to lack of sleep (for some reason it didn't affect the women in the same way). So unless something is done soon, we are going to end up with a generation of fat women living with stupid men.

The main British guru of sleep studies is Dr Neil Stanley, who doesn't share a bed with his own wife. He is evangelical about the subject of separate beds. His studies suggest that on average, couples suffered more than 50% more sleep disturbances if they shared a bed.

Sleep disturbance has a big effect on health, with an increase in incidences of depression, stroke, heart disease and respiratory failure. It's also disproportionately correlated with divorce.

"Poor sleep is bad for your physical, mental and emotional health. There is no good thing about poor sleep," says Stanley. Thus sleep disturbance is not only about your partner kicking, stealing the bedclothes and waking you up in the night going to the loo. Stanley points out that the British average is to have a double bed width of 4ft 6in, whereas a standard single bed is 2ft 6in or 3ft. "That means you have nine inches less sleeping space in your bed than your child has."

Stanley also points out that the habit of couples sleeping in double beds is a relatively recent cultural development. People moved into double beds at the beginning of the industrial revolution, when families moved into cities and found themselves short of living space. In ancient Rome, the marital bed was a place for sex, but not for sleeping.

The idea that people should sleep together out of a desire for intimacy holds little appeal for Stanley: "Sleep is the most selfish thing you can do. People say they like the feeling of having their partner next to them when they are asleep. But you have to be awake to feel that. We all know what it's like to sleep in a bed with someone and have a cuddle. But at one point you say, 'I'm going to sleep now.' At that point, why not just take yourself down the landing?"

Why not indeed? However, for me, such a move would be a radical and somewhat disturbing experiment. Sleeping alone is for old couples and couples who have no physical interest in each other any more. The marital bed isn't just a sleeping arrangement. It represents closeness, sharing, the married state. Without a bed to climb into together at the end of the day, are you really any more than two people under the same roof?

Yet perhaps I am too set in my ways. I shouldn't fool myself. I am old – a few years shy of 60. So why pretend that I am not? Why not behave like the codger I am clearly becoming? My wife wouldn't blink twice if I moved into the next room (she's not what you would call a needy sort of woman). It might even give our sex life a fillip – you know, creeping in to the other's room of a midnight hour and all that.

Yet I just can't quite get my head round it. Perhaps I am just sentimental. To lie in bed and touch your partner at night, even with a partner who has appendages as cold as frozen cod portions, is something you don't ever do with anyone else. To listen to their night noises and experience their odours, however unsavoury.

It is not always a pleasant experience to share a bed with someone. But it is rather unique and it sets the mark on the particular status of the married condition. And most couples continue to take this view – according to one survey, only 8% of couples in their 40s and 50s sleep in separate rooms. The temptation does grow as you get older, though – more than 40% of over 70s sleep apart.

One family therapist put it this way: "The biggest problem in every couple is disconnection. And this decreases intimacy. It starts with, 'I'm going to take this kid here and you can take the other one there.'"

And sleeping alone means physical distance, which can lead to emotional distance. "A logical decision in one area has consequences in other areas."

As it happened, I spent the night before writing this column in the spare bed and I must say I had a wonderful night's sleep. I could grunt and snort to my heart's delight, shuffle about under the covers and wander off to the loo when I felt like it, without having to worry about someone silently cursing me.

I'm thinking a compromise may be in order – perhaps weekends together and weekdays apart. But another part of me thinks it's the thin end of the wedge. And the thick end of a wedge is designed to put a lot of space between objects. Already separated by technology, we will be just two people living under the same roof. That may be a relationship of sorts. But it's not a marriage.