How do you know when you’re grown up — properly grown up? In an age when you’re as likely to crash into your mum as a school friend at Glasto, one of the few reliable signs that you’re over the threshold of adulthood is feeling not entirely comfortable when discussing how much you earn.

There is a moment, probably around your mid to late twenties, when to ask, “How much do you make?” is more of a faux pas than “... and have you ever contracted genital warts?” Money, not sex, is the last taboo.

If someone asked me how I voted, I would tell them. I would also be honest about the number of sexual relationships in my past (although I might do a little redacting, depending on the company). And I will admit to having failed my driving test 13 times. But if you ask how much I earn, I will go all coy and change the subject. My earnings are between me and the nice lady at the film and television branch of HM Revenue & Customs.

You see, I would be embarrassed if it turns out that I am earning more than you, especially if you work with disabled children, but I would be mortified if you are getting a shedload more than me, especially if we are related. Happiness, it has been said, consists of earning that little bit more than your brother-in-law.

I am not alone in my squeamishness. If you value your personal space at parties, start asking people how much money they make and see how much lebensraum you get. Anyone over a certain age will move on swiftly.

Nobody minds talking about what they made in their first job — I would happily admit to making £8,000 as a BBC trainee back in the dawn of time — but as I went through my twenties I noticed that my friends were getting more and more cagey about the size of their pay cheques — as was I. Gradually we learnt the art of showing rather than telling: Mercedes versus Vauxhall Astra, Notting Hill or Hackney, rollups or Silk Cut. Nobody talked numbers any more, they sported brands.

Of course, this taboo is observed most absolutely in the workplace itself. Unless you are compiling the payroll, chances are you will have no idea what the person sitting next to you earns; you might guess but unless you steam open their envelopes you will never be sure.

Naturally, employers are happy with this code of silence; if you take someone on and match the inflated salary they got at their last gig, you don’t want to have to do the same for those already working for you doing roughly similar jobs, whose wages have been going up at the rate of inflation. There is no collective bargaining if everyone is on individual deals.

The disclosures about the BBC were remarkable not so much for their expenses claims as for the bizarre inequities of their remuneration. How does the controller of BBC1 feel about the fact that the director of BBC North is paid nearly 50% more than her? Perhaps he is rebuilding Hadrian’s Wall by hand. Why does the BBC3 controller get more than his equivalent at BBC4? It must add a certain piquancy to corporate awaydays.

Harriet Harman, deputy leader of the Labour party, wants to introduce legislation that will bring transparency into the question of pay, ban “gagging” clauses and make employers publish the salaries of the men and women they employ by pay band. Even the thought of it makes me squirm.

Imagine going into the office one day and finding everyone wearing a T-shirt with their salary on the front: it would be much worse than going naked to work. But would it make for better business? It’s possible. If you knew that everyone you worked with was aware you were earning £500 a minute, you might think twice before taking that comfort break or buying that dodgy Dutch bank.

Knowing what other people earn might actually make businesses function better — all the players at Manchester United know down to the last Ferrari what their team-mates earn, but that doesn’t stop them playing successfully as a team. Public sector workers all have a pretty good idea, too, of how much they are being paid relative to their peers.

You could say that pay banding stifles ambition and rewards longevity rather than merit, but I think it also introduces an element of vocation. You don’t go into nursing or teaching for the money, but it is reasonable to expect that experience and qualifications should be reflected in your salary. People don’t resent pay differentials if they can see the reason for them.

The American company Gore, which makes Gore-Tex, the waterproof fabric, has a flat pay structure: teams vote on who should get extra remuneration. Gore is consistently in Fortune magazine’s top 50 companies to work for and its staff turnover is famously low. Just think how the office dynamic would change if your bonus depended not just on impressing your boss but also on convincing your peers. Every company has a grafter and a slacker; their colleagues know who they are, even if the bosses don’t. An elective element to your salary would certainly make for a more civil workplace — there are going to be a lot of extra cups of tea being made around decision time.

Even though I can see the benefits of all this transparency, I still don’t want to tell you how much I earn. I don’t even want to reveal how much I am being paid for writing this, although I can tell you it is definitely less than the blessed Jeremy Clarkson (to my right) but considerably more than I pay the woman who looks after my children. I don’t think there is much justice in this (although, of course, Clarkson is worth every penny), and for that reason I would like to remain shrouded in mystery.

• My dog is in an interesting condition and I am on stand-by for the patter of tiny paws. Being new to the dog midwifery game, I went online to find out what the form was, only to discover that whelping is as fraught with ideological debate as human childbirth.

On the one hand there is a school of thought that says dogs should give birth naturally, without intervention, except for a little low lighting and their favourite music; in the other corner are the interventionists that recommend regular sonograms and advise you to have a scalpel handy when the time comes in case you have to perform an emergency c-section.

When the puppies are born there are endless decisions as to the right way to wean, house-train and discipline. Mumsnet, that online bastion of right-on, or self-righteous, mothering (depending on your attitude to controlled crying), should open a canine section: Bitchnet.

Editor’s note: Daisy Goodwin was paid £500 for this article

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