It shouldn't come as much of a surprise that rats gamble, since everything that lives and moves gambles. Getting out of bed in the morning is a gamble that the day and life won't end when a hammer that has slipped out of the hand of a roofer two doors down from the newsagent where you get your paper every morning doesn't land on your cranium as you pass. You bet it won't happen, or you stay in bed and sod the crossword. Foxes gamble when they rummage through your rubbish bin that the local hunt isn't about to come round the corner and tear them to pieces (no one having told them about the recent legislation). The pigeon in my garden gambles that the cat won't sneak up behind it as it hoovers up the spilt seeds under the bird feeder. It knows the cat's around, knows the food's around. Doesn't want to die, wants to eat. Takes a risk, on whatever basis pigeons work these things out. Living things gamble or they stay absolutely still and die of starvation.

But here's the clever and the not so clever thing about science: unless all this risky living is taking place in a laboratory, it can't be measured, and if it can't be measured it's just what they call, contemptuously, 'folk psychology'. So they stick rats in a cage, give them four holes to poke into, and see if they go the 'good' route and choose sweeties in smaller quantities but more reliably, or the 'bad' route and choose less reliability in higher doses. Like patients with frontal lobe damage, says the Professor, the rats 'just don't learn from their experiences. They continue to choose from the "bad decks".’ According to him the regular reward is the 'optimal strategy'. Well, according to me and my frontal lobes, and the rats in his lab, we like lots and lots of sugar and we're prepared to wait out a drought in order to get it. In the long run apparently we get less sugar, but that's the Professor's long run. Me and the rats like a little excitement in our lives. So sue us.

The optimum world of neuropsychologists where everything behaves according to a balanced formula of energy and risk versus food and reproductive gain is as neat and boring as living at the end of the Tube line. Even rats bred to live in a cage, while neuroscientists do or don't give them what they never knew they did or didn't want in the first place, can take the unreasonable route. Right on, the rats.