It has recently become fashionable to blur the difference between humans and the rest of the animal kingdom to the point where it virtually disappears. In a way, this is preferable to the kind of idealist nonsense of the past. Humans are animals, and share a number of characteristics with other animals, especially our nearest relatives, the apes. The genetic difference between humans and chimpanzees is only about two per cent. Yet here too, quantity becomes quality. This two per cent represents a qualitative leap, which has decisively separated humankind from all other species.

The discovery of the rare species of bonobo chimpanzees, which are even closer to humans than other chimpanzees, has aroused a lot of interest. In their book Kanzi, The Ape at the Brink of the Human Mind, Sue Savage-Rumbaugh and Roger Lewin have given a detailed account of their investigations into the mental capacities of a captive bonobo, Kanzi. There is no doubt that the level of intelligence displayed by Kanzi is significantly higher than that so far seen in non-humans, and in some respects resembles that of a human child. Above all, it shows the existence of the potential for, say, tool making. This is a powerful argument in favour of the theory of evolution.

Nevertheless, the significant thing about the experiments that attempt to get the bonobo to make a stone tool is that they were unsuccessful. In the wild, chimpanzees use “tools” such as “fishing sticks” to get termites out of their nest, and even use stones as “anvils” to crack nuts. These operations show a high level of intelligence, and undoubtedly prove that humankind’s nearest relations possess some of the mental prerequisites needed for more advanced activities. But as Hegel once remarked, when we want to see an oak tree, we are not satisfied if we are shown an acorn instead. The potential for making tools is not the same as actually making them, any more than the mere possibility of winning £10 million on the lottery is the same thing as actually winning. Moreover, this potential, on closer examination turns out to be extremely relative.

Modern chimpanzees occasionally hunt small monkeys. But they do not use weapons or tools for this; they use their teeth. Early humans were able to butcher large carcasses, for which they needed sharp stone tools. No doubt, the earliest hominids used only ready-made implements like sticks for digging up roots. This is just the kind of thing we see with modern chimpanzees. If humans had stuck to a mainly vegetarian diet, there would have been no need to make stone tools. But the ability to make stone tools gave them access to a whole new supply of food. This remains true even if we accept that early humans were not hunters but mainly scavengers. They would still need stone tools to cut through the tough hides of large animals.

The proto-humans of the Oldowan culture in East Africa already possessed quite advanced techniques for making stone tools by the process known as flaking. They selected the right sort of stones, and rejected others; they used the correct angle for striking and so on. All this shows a high level of sophistication and skill, which is absent from the “work” of Kanzi, despite the active intervention of humans aimed at encouraging the bonobo to produce a tool. After repeated efforts, the experimenters were forced to admit that:

So far Kanzi has exhibited a relatively low degree of technological finesse in each of [the four criteria] compared to that seen in the Early Stone Age record.

And they concluded:

There is, therefore, a clear difference in the stone-knapping skills of Kanzi and the Oldowan tool-makers, which seems to imply that these early humans had indeed ceased to be apes.[47]

Among other differences separating even the most primitive hominids from the highest of the apes are important changes in body structure related to the upright stance. The structure of the bonobo’s arms and wrists, for instance, is different from that of humans. The long, curled fingers and short thumb prevent it from gripping a stone effectively enough to strike a powerful glancing blow. This fact has already been pointed out by others. The chimpanzee’s hand has a fairly well developed opposable thumb:

“but it is stubby and meets the forefinger along its side, not at its tip. In the hominid hand, the thumb is much larger and is twisted so that it faces the forefinger. This is a logical concomitant to bipedalism and produces a great increase in dexterity. All hominids seem to have had this kind of hand – even afarensis, the oldest one now known. Its hand is scarcely distinguishable from a modern man’s.”(Johanson and Edey)[48]

Despite all the efforts to blur the dividing lines, the difference between even the most advanced apes and the most primitive hominids has been established beyond doubt. Ironically, these experiments, intended to disprove the idea of humans as tool-making animals, proved exactly the opposite.

  1. Savage-Rumbaugh, S. and Lewin, R. Kanzi, The Ape at the Brink of the Human Mind, p. 218.

  2. Johanson, D. and Edey, M. Lucy, The Beginnings of Humankind, p. 325.