THE LAST WORD

he news published in Nature last week that mother rats are cleverer than their virgin sisters means that motherhood is both good for the brain and good for Britain.

This is splendid news. All those married men in the Cabinet may soon forfeit their sermons on marriage in favour of motherhood (whether single or married). And instead of seeking Viagra on the NHS, men may be encouraged to ingest oestrogen to improve their performance.

Researchers in Richmond, Virginia, report that the differences between their victims weren't genetic - all the rats being female - but derived from the greater volume of female hormones produced by pregnancy. This, it is believed, may have long-lived effects on human faculties, particularly the work of memory located in the hippocampus.

We should not rush to make too much of this discovery, however. Haven't men disappointed us before when they've trawled the bodies and minds of rats to discover the meaning of life? In this case the neuroscientist Craig Kinsley was prompted to compare virgin and mother rats when he noticed his wife's "amazing transition" after the birth of their daughter - he was astonished to discover that she could do several things simultaneously. Will his rats explain the conundrum played out every week in The Royle Family: why does Barbara do everything while Jim can't get out of his chair?

But you know there might be something in it. I have consulted the characteristics of the little community nesting in my own household, and suddenly all is revealed.

The only virgin is Rosella, a cockatiel much loved by myself who is the image of Dusty Springfield with bouffant and orange cheeks (actually, her ears). She is, as far as we know, a virgin and she is, we all aver, raucous but simple-minded.

She can do only three things, and only one at a time; she's good at looking at herself in the mirror - nothing gives her greater pleasure, confirming suspicions of virginal vanity; she can impersonate a Canon bubble-jet printer but not a Hewlett Packard laser jet; and she can pretend to be a fire alarm but not the Cuban All Stars.

I'd thought she was stupid because she is a cockatiel. Not so; it's because she's a virgin.

Then there was "The Guvnor", a Russian hamster who spent too much time alone in his room when he wasn't tramping on his treadmill. He could not cope with complex tasks. It must be admitted that he could connect with paper - not to read, but to shred. And he could manage to masticate a carrot. But not simultaneously. Yep, you've guessed. A virgin.

Our late and much loved Robin (the dog) lived a long life in which he learnt to love pasta, humans and snooker on telly. He was a cosmopolitan dog. As far as we know he was a virgin, unless his affair with the hairy hearth rug counts. And then there was that business with the leather briefcase. But no babies and not very bright.

Sally Cinnamon and Roxanne Sade, by contrast, are mothers. These feline rappers are an affront to the married men's movement. You should see them sashay down the railway embankment to hang out with Magnus, the heavy breather in the bushes. If their virginity had nine lives, they'd have lost all of them.

The theory must be right. These sistas are not only hot but clever. Since her whoring and mothering season, Roxanne can open a kitchen cupboard containing goodies with one paw. She is, in care-in-the-community speak, "capable of independent living".

Sally used to know what time the children (human) came home from school and waited in the window to greet them. These gals taught their kittens to eat from a bowl, shit in a tray and pretend to adore humans. But behind Sally's devotion also lurked something more sinister. When she was in motherhood mode, other creatures seemed to come to sudden, mysterious and sticky ends.

Was her self-satisfaction due to her motherhood and "fulfilment" or was it because she enjoyed being a serial killer? Whether as a killer or a mother she was clever. If that was due to her hormones, they didn't discriminate between benign or malignant activity.

That's the problem. Science can only tell us so much, and it tells us as much about who is asking - as well as answering - the questions.

So many women who have had babies testify to the exhausting alchemy of joy, sleep-starvation and sclerosis of the brain during and after pregnancy. So they'll be reassured that neuroscience is, at last, telling mothers that they're not ne'er-do-wells after all; their brains are even better than their blokes'. But then they knew that already.

Kinsley's research tells us about the awe of a man who witnessed his wife's metamorphosis via motherhood into wonderwoman. No doubt he noticed that parenthood changed her life (if not her brain). But not his.