We Owe our Success to our Hands, not our Heads

Posted on 23rd January, 2026 in News

Never has so much been written about why we humans dominate the planet. The consensus has generally been that it is because we are more intelligent than other animals, and the most popular theory is that our bigger brains have enabled us to live in larger, more complex groups. The evolution of language has been seen as a crucial factor, along with our ability to indulge in abstract thinking. Anthropologists have even gone on to speculate that being able to produce representational art, tell stories, believe in gods and to play music were key to the success of our own species Homo sapiens. Artists and the humanities-educated chatterati have understandably pounced on these ideas and trumpeted them as proven facts. There is every reason, however, to believe that in defending the dominance of their worldview they protest too much. After all, it is engineers and labourers, not people who are noted for their aesthetic sensibilities, religiosity or artistic ability, who have built the modern world – not artists or musicians.

In fact, it is difficult even to prove what we have always assumed, that humans are cleverer than animals. In many cognitive tests, animals can actually outperform humans. Experiments on spatial memory show that chimpanzees can remember the position of large numbers of points on a computer screen far better than people. Animals as different as jays and squirrels also perform astonishing memory feats to find nuts they have cached in the soil months before. Whenever we have presented animals with cognitive tests that relate to their ecological needs they turn out to be far cleverer than we have given them credit for. Even the long-held viewpoint that humans are the only species that is capable of making and using tools has long-since broken down. As long ago as 1962, the primatologist Jane Goodall discovered that chimpanzees use grass stems to probe for termites within their nests, and leaves or handfuls of moss to raise drinking water to their lips. We have since found more and more examples of tool use in a huge range of creatures. Chimpanzees fashion a range of wooden tools to break into bees’ nests, spear bush babies and dig for roots in the soil and they even use stone hammers to break open the shell of nuts. Elephants brandish sticks in their trunks; new Caledonian crows fashion hooks from the leaves of Pandanus palms and use them to extract grubs from within the branches of trees; dolphins cover their beaks with sponges to protect them when they are foraging on the ocean floor; and octopus cover their vulnerable bodies with cocoanut shells. And in recent weeks, media reports have showcased a cow, once thought of to be amongst the least intelligent of mammals, that  has learnt how to use a broom as a tool, holding it in its mouth to scratch itself. 

So if it is not just the intellectual ability to make and use tools that sets us apart, what is it that has put ourselves on a course that has led us to dominate the planet? The answer is in plain sight – our hands. All the tool-using animals I have just mentioned are limited in their capabilities by their anatomy. No matter how intelligent, dolphins, crows and cows could never freely manipulate a wide range of tools because all they have to do it with is their mouth. Elephants’ trunks make them more versatile at using tools, since they are long and flexible, and end in two sensitive “fingers”. However, since they are not stiffened by bones, trunks have limited strength and elephants only have one trunk, so they cannot hold a tool in one trunk and work on it with another. Great apes have mobile arms and hands and jointed fingers covered with with soft pads backed by nails. This allows them to pick fruit from the trees, test whether it is ripe, and remove the peel, but because they have to use their hands and arms for climbing, in many respects they are poorly adapted for manipulation. They have long fingers to hook around branches and short thumbs to allow them to let go more easily. Consequently chimps cannot hold onto spherical objects like stones with any strength, while sticks all-too easily slip through their grasp. Moreover, being quadrupedal, chimps have to squat on their haunches to perform any task and so cannot swing their arms about with any speed or power.

Our ancestors, the early hominins were different from the very start. As soon as they came down from the trees, around five million years ago, the constraints on the evolution of their arms was lifted.  Freed from climbing duties, their fingers could shorten and their thumbs lengthen, allowing them to hold onto large stones and grasp thick branches in power grips within their palm, and to manipulate small sticks and stones in precision grips within their fingertips. And standing upright, they could use muscles from all around their body to help swing their arms. By rotating their shoulders with their leg and trunk muscles, they could power sling actions that would swing their upper arms, and then their forearms. This allowed them to hit harder, dig deeper and throw further than any other animal. They could even hold a stick in a power grip with their palm and use it as a third element in the sling action, to swing it as a club. Hominins could break open marrow bones with stones, and stab or pierce live prey with simple spears. The could also use their arms in a more controlled way like cranks to sweep their hands back and forth to use knives to slice through animal flesh. Using simple hand held tools hominins could access a far wider ranger range of tools than their rivals, and become effective foragers and feared scavengers and predators.

By two million years ago, with the advent of the first totally terrestrial hominin Homo erectus, the morphological transformation of the human body was more-or-less complete. From the neck down these early relatives of ours would have looked just like us. The head was different, however, as their brains were not much larger than those of chimps and half the size of our own. But it was at this point, unable to escape from predators into the trees, that selection pressures must have focussed more on the brain and on improving intelligence.

Part of the increase in brain size that has occurred since then must have been down to the need to provide our hands with better control. Certainly, huge areas of both the sensory and motor cortex of human brains are dedicated to our hands, giving brain “homunculi” their gigantic hands and grotesque, distorted appearance. But a lot more must have been down to their need to learn from other individuals how to make and use better tools and to teach their children and other relatives and friends how to do it. Being able to observe other people would have been important, and being able to speak and listen to others would have also helped. And being able to cooperate with others would have enabled them to share important tasks. Eventually these enabled members of our genus to perform a myriad of other useful tasks with our hands, such as to set and light fires, sharpen their tools, haft them onto handles, make bows and arrows, build bigger homes and make clothes.

Of course, one major consequence of learning how to perform these useful practical accomplishments, the selection pressures would be to improve our social skills, and strengthen our cooperation, enabling us to live in larger, more cohesive groups. And it would also enable us to carry out more enjoyable tasks, such as drawing animals, making jewellery, fashioning and playing musical instruments, and making up and telling stories, even ones about non-existent spirits and gods. By improving our communication skills we would have become more quintessentially human.  It is hard to see how these new-found abilities would have improved our survival prospects, however. Quickly-drawn sketches are just as informative as beautiful oil paintings; simple drum rhythms just as good at conveying information as complex symphonies; and it is hard to imagine how listening to sagas about the amorous adventures and warfare of bloodthirsty warriors would have helped hunter gatherers in their everyday lives.

Much has changed since humans reached the peak of their abilities to survive unaided in the wild as hunter gatherers. The advent of agriculture ten thousand years ago forced us to adapt our tools for the cultivation and harvesting of plants and herding of animals. We have learnt how to build machines and to harness power from draft animals, from the wind and from the flow of streams to drive them. And in the last three hundred years we have learnt how to extract power from fossil fuels to build a new industrial world. Our engineering abilities have enabled us to make tools and build machines that carry out many of the essential manual tasks with which we were formerly burdened. We can do so many things while hardly lifting a finger that we have begun to forget how hard it is to live without complex tools and powerful machines. We have begun to disregard the importance of our hands as tools, and to denigrate the people who build and run the world in which we live. We all need to learn to value and respect the individuals who work so well together to keep the world going – not artists and musicians, but engineers.