The Emergence of Intelligence

"What a piece of work is a man! How noble in reason, how infinite in faculty! … In apprehension how like a god!"

— Hamlet, William Shakespeare

The question of intelligence is a deeply enigmatic one. It is a marvel of metacognition that we, beings of intellect, can question and reflect upon it at all. Yet, as a species, we have come to identify ourselves by our ability to think. And by this ability, we have often proclaimed ourselves above and apart from other living beings.

The theory of evolution poses an opposition to this idea. It proposes that all species are connected to each other through a long history of evolution, and the emergence of morphological traits, as well as the structure of the brain and therefore our mental capacities, can be accounted for by natural selection. The Victorian era witnessed a vigorous intellectual debate between two brilliant biologists on this subject—Charles Darwin and Alfred Rüssel Wallace.

In essence, the theory of evolution posits that random genetic mutations that cause individuals to be slightly better adapted to their environment tend to prevail and propagate within the population. Mental abilities, to him, were not fundamentally different from physical ones. Darwin insisted that intelligence and other human intellectual achievements could be explained by the same natural selection that might explain fingers and toes. Individuals with some form of primitive mental capacity were selected for due to increased survivability and progressively, organisms began to develop intelligence as we know it today.

Wallace, on the other hand, argued that certain quintessentially human abilities like mathematical and musical talent could not possibly have arisen through the blind workings of chance. After all, what selection pressures in the wild could possibly have led to the evolution of latent abilities like learning the calculus, solving the Rubiks cube, or enjoying music?

According to Wallace, besides raw natural selection, we have encountered another perplexing, yet equally powerful driving force—culture. With the emergence of culture and literature, human evolution became Lamarckian—not just genetic information, but knowledge gained over the lifetime of a parent could be passed on to the offspring.

The emergence of extraordinary intelligence, coupled with culture, helps us evade the need for further specialization through long, painstakingly slow natural selection. We have stumbled upon a sort of master key to evolution. We can colonize the Arctic without evolving a fur coat, take to the skies without evolving feathers and probe the oceans without evolving fins, all in one lifetime.

These abilities obviously exceed anything most humans might need to cope with their natural environment. This is especially true of conventional intelligence, the kind reared in schools and colleges. Consider an illiterate child from a tribal society. Given a modern education from primary school through college, they will be indistinguishable from any other child brought up in the cities. The child possesses a potential intelligence that they never would have needed for coping with their natural environment.

Evolution through natural selection is a stringent and ruthlessly efficient process. When an ability is beneficial for survival and propagation, it is passed on to the following generation. Thus, Wallace argues, natural selection can only explain the emergence of actual abilities expressed by the organism—never potential ones.

We know that the tremendous advances in the intelligence of the human species have occurred relatively recently—just about a thousand years ago. Human species have, however, existed long before us sapiens. Cro-Magnons and Neanderthals lived up to 120,000 years ago, and both species had cranial capacities larger than ours, hinting towards potential intelligence equal to or even greater than ours.

It was baffling to Wallace how these brilliant abilities waited a million years to be realized. So much so, that the only feasible explanation, he thought, was a “higher intelligence” directing the evolution of human nature.

On the origin of human intelligence, most modern theories resemble Darwin’s explanation on a fundamental level, but with important distinctions.

The modern argument suggests that esoteric and abstract abilities such as art, music, humour, fiction, religion, and philosophy may have evolved as specific manifestations of general intelligence—evolutionary side-effects, if you will. Intelligence, at its core, may be reduced to the ability to solve problems—especially ones pertaining to survival. If so, then Darwin’s natural selection accounts for these products of intelligence that enhance survival and propagation. For example, the invention of weapons most likely evolved as an intelligent response to a need for protection from predators and rivals. This explanation even extends to more complex yet survival-oriented abilities like communicating, hunting, hoarding food and constructing shelters. Once this intelligence was in place, it was used for all sorts of other things.

Despite research, intelligence, much like numerous other things that are so widespread in the biological world, is far from understood. How neurons actually perform abstract operations in mathematics, how our brains seamlessly interpret symbols in language and abstracts in art, the immense complexity of being creative, all remain as mysterious to us now as they did to Wallace. It’s inevitable he felt impelled to invoke divine intervention.