More than two million years ago,
Homo habilis invented the tool. Next,
Homo erectus made use of fire; then Homo sapiens conquered the world. In just a few millennia, in the era we call
the Palaeolithic, human beings, walking upright and with tools in each hand,
imposed a new knowledge and a new way of life on the world.
Indispensable to all these stunning achievements is the
longest-running of them all: the aggregate development of culture by thousands of human
generations whose lifetimes worked nonstop to improve and adapt the myriad ways
in which we can think, behave, and make decisions, both as collective minds in
groups and as solo individuals working out the problems of the universe as well
as our next cup of coffee. The strength
and plasticity of culture, as well as the human brain, makes us the world’s
most adaptable and successful species—through the collective brain and
creativity of humankind.
Symbolic thinking
Our unique human ability to imagine, manufacture, and put to
use symbols is an act of absolute liberation from the material world and from
the present moment, allowing us to see beyond what is in front of us, backwards
into the past, and forward into the rich potential of the future. Emerging evidence from archeology is
showcasing that symbolism began to emerge as part of a great cognitive
revolution in the form of art (now beyond 40,000 years ago) and mathematics at 30,000.
While the flowering of mathematics in applied
problem solving goes back only 500 years to the Scientific Revolution, its
origins are ancient and worldwide as a symbolic language of its own that
developed independently as a trained skill, from simple computation to defining infinity.
However great the potential of abstract thinking,
engineering still must fit the numbers and concepts to the human form. The operations researcher must fit the design
of space vehicles like the LEM to the dimensions of the human body and
brain. Animal traps and weapons
ballistics had to fit what humans could fashion, carry, and track. In this way, our own inventions must work
for us. Culture, as the Ur-invention, became the
invisible force driving our brains, bodies, and behavior both as individuals
and groups (thinking, learning, expression, and problem solving), from our
first survival on the African plains to the sophistication of urban life on-earth
and off. On the Internet and in subcultures,
using technological acumen and prolixity---cultural intelligence underlies and animates
everything human, yet is certainly the least understood of anything humans have
produced.
Art
Culture could not begin its own invention without our
species' ability to think symbolically.
This mindset began in the Paleolithic, the early phase of the Stone Age,
about 2.5 million years in duration, marked by stone, wood, and bone tools, and
cave art starting with the monumental act of leaving handprints created by our
prehistoric relatives. These handprints
in red ochre have moved back in time from the Maltravieso cave in Spain, dated
back 64,000 years and painted by a Neanderthal, well before Altimiria’s bison
of 16,000 to 9,000 BCE, the “Sistine Chapel of Paleolithic Art.” Discoveries in the Blombos cave in South
Africa then moved the clock back on art-making with a 100,000-year-old
pre-European animal-bone paintbrush and palettes, abalone shells for mixing red
ochre paint, and sea-snail shells with holes for stringing and wearing as
jewelry.
In his article on symbolic thought (New York Times,
Dec. 5, 2014), Ferris Jabr notes the significance of a simple handprint: “The suggestion of a human hand on a cave
wall, a nation’s flag, even a Rothko—each is a powerful mental heuristic
designed to conjure a particular emotion, a memory, an idea.” The elegance of symbols, Jabr says, is that
they bypass the issues of changing the world in the act of changing the way we
perceive it, enlarging its possibilities by acts of thought alone. That is, by the power of ideas.
Language
Evidence of language is also moving backwards on the
timescale of human evolution. Like art
and jewelry, speech is intimately involved in conceptual and imaginative
thinking. Recent research points to
language development as occurring millions of years ago rather than the
benchmark of just 200,000 (Sawallis et al., 2019). Two forces, first, the reshaping of the human
throat, and second, syntax, the way words work together in sequential order to
convey linguistic meaning, are considered the critical events in the body and
brain that make symbolic communication possible. Unfortunately, linguistic
evolution, unlike physical development, doesn’t have much data to work with
because soft tissue doesn’t leave fossil evidence. But speech is not just a physical and
muscular act made possible by laryngeal descent—our lowered larynx compared to
other primates. It is a mental capacity
that is at once intensely social and inherently symbolic.
Mathematics
The oldest known mathematical artifact is the Wolf Bone of
Czechoslovakia, with 55 notches in two groupings, dated at 30,000 years ago;
the second-oldest is the Ishango bone discovered in Zaire, dated 10,000 years
earlier, with three columns of marks suggesting computation either as a tally
or a calendar. Hunter-gatherer societies
used number systems, and the names for numbers can be tracked as they gradually
increased in independent lexicons over time.
The earliest mathematical texts are Egyptian and Babylonian
dating to 2,000 BCE, covering arithmetic, geometry, and the Pythagorean
theorem, continuing in ancient Greece.
The Greeks introduced deductive reasoning and formal proofs to
conceptual thinking about math. The
Romans applied math to surveying, structural and mechanical engineering,
bookkeeping, lunar and solar calendars, and the arts. The Chinese added place value and negative
numbers. The Hindu-Arabic numeral system
is in worldwide use today, coming from India in the first thousand years BCE. From the Maya of Mexico and Central America
came the most critical concept to computation – the zero, a triumph of abstract
cognition.
