Science: You have to laugh: it's the only medicine for a ticklish rat

Horizon

BBC1

Thanks to last week's , "Beyond a Joke", Professor Jaak Panksett will go down in scientific history as the man who made a rat laugh. No small feat. Panksett tickles rats, and using bat-detector equipment he records their hysterics. It's a sort of chirpy chuckle, not very infectious, but it's nice to know that rats aren't all business. I wondered if one could make a cat laugh using the same technique. In the spirit of scientific inquiry I cornered our own cat, Kipper, and tickled him. He bit me.

Before got down to its serious points about laughter and the importance of play, it first had to convince us to take its rat-amusers, laugh-trackers and tickle-monitors seriously. Denman Rooke's film tried to differentiate between "the self-tickle and an external tickle", to figure out why you can't tickle yourself, using a machine that appeared to have been made from an old movie projector with a foam finger on the end.

It was hard to divorce the absurdities of these people's jobs from the importance of their findings, which were a revelation. Human laughter, like that of rats, is a basic, instinctive language, which has everything to do with social relationships and nothing to do with humour. We laugh all the time, and not at jokes, but at statements like "Hey Joe! Where you been?" and "Here comes John!". Actually, this is a little depressing.

There's more. We have another laughter trigger in our higher brain. In a study of epilepsy, a young woman with electrodes implanted in the speech centres of her brain was shown a picture of a fork. When they turned on the juice she laughed so hard she nearly came out of her electro-hat. Watching herself crack up on video some years later she said, "It was so not funny", and laughed again. Weird.

About halfway through, the programme had to make a leap from these discoveries to their implications for child development. While the link is far from tenuous, it was a little difficult to follow at first. Before we knew it, we were talking about children with Attention Deficit Hyperactivity Disorder or ADHD, a syndrome that seems to have gathered a new initial since I last heard about it. There is no doubt that ADHD is debilitating, but in its most extreme form it can be treated with drugs, specifically Ritalin. The worry is that it is becoming a catch-all behavioural diagnosis. One in 18 American children is now classed as suffering from ADHD, and the US consumes five times more Ritalin than the rest of the world combined. In Britain, Ritalin prescriptions have leapt from 2,000 to 90,000 in the last six years.

Was this the same programme as the one I started watching, the one with the laughing rat? Yes, it was. Professor Panksett concluded, through "his growing understanding of rat laughter and play", that much of what is diagnosed as ADHD is "simply wanting to play in the wrong places". More controversially, he opined that ADHD may have once been a positive trait, "back when we were hunter-gatherers". I find the term "hunter-gatherer" - science-speak for "caveman" - preposterous. Who knows what hunter-gatherers got up to? It has become a simplistic way to account for traits which don't seem to fit into our modern life as shopper-drivers. The widespread misdiagnosis of ADHD is a scandal, but describing the behaviour of uncontrollable children as just so much leftover Ice Age boisterousness is not particularly helpful, or even enlightening.

Some confusion is inevitable with issues this complex, but there is one clear message: "Increasing class time at the expense of play does not increase academic performance. On the contrary, it produces many of the early signs of ADHD." Teachers have more or less known this all along, but these days no one listens to them. It's enough to sober up a rat.