It's a lot harder than one would imagine finding a really good example of a chimpanzee painting. Neither of the two I've selected as examples are beyond reproach: they are not immaculate works of the chimpanzee type. Most normal people would be likely to notice the vague centring in Willi Baumeisters work Mortaruru with Red Overhead. Would a chimp put the ovals one above the other so perfectly? With a bit of luck, maybe. The scribbly bits at the bottom give us a feeling that a chimp might have done them if it had picked up the right sort of tool. I think we can give it about eight out of ten if we mark entirely on the degree of authenticity in the chimpanzee painter illusion - but we can see luck would have had to have been involved.

Baselitz is maybe a better chimpanzee painter - or at least his work More Blondes is a more compelling example of a chimpanzee painting. The feeling of utter abandon in the paint starts us well. The layering is a further authentic touch - we can see the animal picking up one brush after another, and charging each in turn with color - perhaps been previously coached to the task by an animal psychologist, or indulgent owner. We see it splodging away, perhaps with a momentary air of diligent interest, before deserting its easel as some other fancy takes it - and we see it gambol off, brush in hand, in search of some more stimulating pursuit. But this is rather a superficial judgement. If we stick to our original definition - "most normal people would think it could have been done by a chimpanzee" we soon see the flaws in it. Many normal people would question whether the registration of the green streaks of paint over the reddish ones would be achievable by a chimpanzee.

But worse than that - if we turn the painting upside down we find that it takes on a sort of figurative air, and the co-incidence required for this is all too much. We seem to see a crudely executed picture of a person sitting or lying on a bed or chair. We seem to almost switch to a toddler painting.

Some key points for a genuine chimpanzee painting: