The inhabitants of Arab countries – unlike Her Majesty's subjects here in Britain – are not generally expected to take an interest in the family lives of their rulers. In fact, it's a subject that ordinary Arabs, even if they do happen to be curious, are rarely permitted to know much about.

I was reminded of this yesterday with the announcement that Prince William, second in line to the British throne, is to be married next year. On such occasions the BBC abandons its usual sense of objectivity and starts behaving like Syrian state television. All other news gets pushed into the background, to be replaced by a succession of people, from the prime minister downwards, all saying how thrilled they are. A headline on the BBC website even proclaimed: "Royal engagement delights world" – as if the rest of the world really cares. In due course, the whole of Britain will be required to celebrate with a public holiday for the actual wedding.

Contrast this with the late King Hassan of Morocco whose wedding was held in secret. "Nobody knew when [King Hassan] wed his Berber wife Lalla Latifa and she never appeared in public or featured in family photos. He is understood to have maintained an extensive harem who lived in isolated luxury and were never allowed to bear children."

That is still the general rule among the more traditional Arab monarchies; royal wives are mostly invisible and in some cases it's not even clear how many wives the rulers have. Much the same applies to the increasingly monarchical republics, too. A few royal (or semi-royal wives) have been allowed to develop a public persona – in Jordan, Qatar, Egypt and Syria – through charitable work, but that's about as far as it goes. Others are treated as if they don't exist.

Perhaps this is changing a bit. Morocco's current king, Mohammed VI, broke somewhat with his father's tradition when he married. Official photographs were issued, though the wedding ceremony was held in private. Public festivities were planned but then suddenly postponed because of "the continuous aggravation of the situation in the Palestinian territories".

One obvious factor behind this low-key approach to the family lives of Arab royals is the seclusion of women, along with the idea in Arab-Islamic culture that it's bad form (at least for males) to show an interest in other men's wives.

But I think it's also connected with maintaining a distance between rulers and ruled. Arab rulers would not dare claim to be deities like the Roman emperors but they do try to give the impression of being more than ordinary mortals – remote figures who always know what's best for their people and whose wisdom is not to be questioned.

The British royal family, on the other hand (along with others in Europe) have tried to appear closer to the people by humanising themselves – with disastrous results in the case of the dysfunctional Windsor family, whose trials and tribulations have at times resembled a national soap opera. Far from establishing common ground with the public, this has tended to give the impression that Queen Elizabeth is the unfortunate matriarch to a bunch of posh, out-of-touch weirdos.

In Britain, we know plenty about our royal family, and certainly more than is good for them. But in terms of the way our country is governed, it doesn't really matter. These days, we keep them in their palaces mainly for their entertainment value. They may still own large tracts of the country but they don't run it: that is the job of elected politicians.

In Arab countries, though, kings and hereditary presidents actually govern – which is a major difference. Arabs have a right to know more about them, and what sort of people they really are.