Top marks to the clever scientists at the University of Bonn, who have uncovered the fact that men are motivated by money. The revelations don't end there. They have also discovered that men like money even more if they know they've got more than the next guy. Astonishing.

The research, published in the journal Science, is the result of extensive tests on 38 pairs of males who were asked to perform a simple task for financial reward. I'm thinking polishing a car or tuning a TV. The guinea pigs were paid different amounts and told what their counterparts earned.

Using magnetic resonance tomographs, the experts examined circulation during the activities. High blood flow indicated the nerve cells in the ventral striatum, the "reward region" of the brain, were particularly active. A wrong answer, and no payment, resulted in reduced blood flow. But the area "lit up" when volunteers earned money, and showed more activity if a participant received more than his opposite number.

There are no results recorded for the rush of blood to the head brought on by wasting money on silly studies. This is up there with some old favourites stashed in our Daft Scientific Studies file: people with big hands feel pain less; alcoholics have difficulty understanding people; extreme sports enthusiasts have a greater need for excitement.

So you can keep your Herzberg, Maslow and McGregor, and all their years of study into motivational psychology. And you can bin traditional economic theory that assumes it's the size of the reward that's important. It's all down to a healthy competitiveness.

Franklin D Roosevelt once said: "Happiness is not in the mere possession of money; it lies in the joy of achievement, in the thrill of creative effort."

Poppycock, say Bonn's boffins. And anyone who has ever lived in the cash-obsessed, materially covetous real world.

There's another dimension the scientists have yet to formulate, although I'm sure they're investing much time and money on the next step in their quest to understand the getting-one-over-on-Andy-in-accounts phenomenon. That's how you convert your cash into goods to further promote the envy factor.

I imagine the next round of research is already under way. A whole university-load of neuroscientists is, at this very moment, wiring a bunch of blokes up to really expensive machines to measure their responses when they're told that Sid at number six has a new Saab or Pete in personnel has a plasma telly.

The my-wallet's-bigger-than-your-wallet has long been the approach of choice for flexing your machismo. But chaps are getting more refined. It doesn't have to be hard cash you flash. There are more subtle ways of displaying your plumage.

When they start waving them in our office - wallets, silly - it's techie kit that gets them going. The smaller, the better, strangely. Music collections are also a hit. Increasingly, these are virtual, so not much substance there. And then there are allotments. Don't underestimate them - the selectiveness of the produce grown or the sheer size of the parsnips. It all serves to put the test into testosterone.

Meanwhile, we have to wonder why the brains of Bonn did not test women. Maybe this is ongoing. Rumour has it the results have been delayed because the subjects couldn't make up their minds what colour of money it was they wanted, and whether it would match the curtains.

So what might light up a woman's reward centre? Shoes to die for? Dazzling jewels? Baileys on ice? No - forget those clichés of birdness. Just knowing you earn more than Andy in accounts will suffice.