A FEW years ago I had a conversation that utterly changed my attitude towards animals. The topic of this conversation was not, in itself, particularly fascinating, being concerned mostly with mosquitoes and marshmallows. The discussion did not flow easily, partly because my interlocutor kept scratching her bottom and trying to stick a twig in my ear. What made this conversation extraordinary, however, and unlike any other I have had, was that it took place with a chimpanzee.

Panbanisha, a 14-year-old female bonobo or pygmy chimp, had been taught to “speak” by scientists at the Georgia Primate Centre using a pictorial keypad and voice synthesiser. At the time of our meeting, she had assembled a working vocabulary of 250 words, but an understanding of perhaps 3,000 more. From these, scientitists concluded that Panbanisha understood such concepts as loss and regret, the past and the future, truth and falsehood. She was able to construct quite complex sentences, and knew the difference between “put the water in the orange juice”, and “put the orange juice in the water”; she was, in short, a great deal more coherent that John Prescott.

I left my encounter with Panbanisha convinced that animals do think. The issue has long divided scientists. Some argue that animals appearing to perform mental feats are not motivated by thought but by automatic mechanisms and responses to stimuli. Others maintain that since thinking and language are the result of human evolution (we think because thinking has proved a useful asset), we should therefore expect to find that non-human animals have attained similar, if less well-developed, cognitive and rational abilities. Some go even further, arguing that there is a “language” common to all animals, with four basic topics of conversation: who’s having sex with whom, who’s boss, what’s for supper, and property values (the right postcode, if you are human; the best branch, if you are a chimp.)

We are heading into Dr Doolittle territory here, but if modern zoology has revealed one thing above all, it is that animals are far more sophisticated in their mental calculations than previously imagined. This is not merely true of those creatures that happen to be on the evolutionary trail closest to our own. Betty, a New Caledonian crow at Oxford, was recently filmed bending a length of wire in order to hook a bucket, suggesting that birds know how to construct tools. An even more extraordinary test was recently carried out on two ravens, proving that these birds are capable of complex deception. During an experiment to explore bird foraging, Austrian scientists found that the dominant raven used his subordinate to find out which of several tins contained cheese, and then bullied him away from it; the subordinate raven, however, developed a devious tactic by pretending to find food in one tin, luring his boss over, and then, while the dominant male was rummaging in the empty tin, slyly sidling off to the full one. The dominant bird, when he discovered the trick, displayed all the symptoms of extreme raven irritation.

Descartes held that speech and reason set man apart from all other animals, and thus non-human animals were beyond ethical consideration. The slow erosion of this approach is one of the most important societal changes of the past 40 years. While there are still arguments over what a fox feels as it is chased by hounds, almost nobody would now argue that animals are beneath moral consideration. True, we remain deeply confused in our attitudes: the number of animals used for research is sharply down, but the hideously cruel foie gras industry has doubled in size over the past 14 years; few still wear fur, but we choose to ignore the often unspeakable conditions on factory farms. Yet the general trend is undoubtedly towards humane treatment of animals, and greater humility in human beings: less, and less cruel experimentation; food raised without suffering. By 2012, every one of Europe’s 200 million hens will be legally entitled to a perch. A small step up for chickens, but a revolution compared with the way previous generations have approached barnyard animals.

The change springs not from mere sentimentality or anthropomorphism, but a realisation, powered by scientific discovery, that the distance between animal and human being, between us and them, is far smaller than tradition and religion have asserted. That gap grew narrower still this week with the discovery of Homo floresiensis, or Flo, the miniature cousin of man, 18,000 years old and 3ft tall. Our long-assumed uniqueness as a species was tempered by the knowledge that all those years ago another sort of human being walked the earth, albeit with smaller steps.

Flo was different; but not so different that she, and you, and I, and Panbanisha the chimpanzee, could not have sat down together and had an interesting conversation about the things that interest us all: the boss, sex, food and real estate.

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