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Tool Use, Culture and Human Hubris

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Chimpanzees, our closest relatives, demonstrate something awfully close to culture, once considered uniquely human. Chimps toy with cultural evolution through tool use, also once regarded as exclusive to our species. A study published on January 30, 2013, in the journal PLOS ONE demonstrated how a cohort of chimps wise in the ways of using a straw to suck juice out of a container can pass on that knowledge by demonstrating the technique to naive chimps.

We humans have always thought of ourselves as particularly intelligent, special, above all other animals. Religion tells us that only we were made in the image of god. The son of god comes in the form of a man, not chimp or weasel. We proudly note our compassion, humor, altruism and impressive capacity to generate language, mathematics, tools, art, and music. In citing this self-serving list to bolster our claim to exalted status, filtered expediently to our benefit, we assume that humans possess, and other animals utterly lack, these honorable traits or capabilities. We ignore the inconvenient fact that we choose to define and measure intelligence in terms of our greatest strengths. We arbitrarily exclude from the definition of intelligence higher brain functions in other animals. We make bold claims of our uniqueness and divine status, only to find over time that each claim ultimately fails as we advance our understanding of animal intelligence and behavior. There is no better example than tool use and culture. (All the examples below are from numerous scientific journals and books, all of which can be found in the bibliography in Chapter 3 of Beyond Cosmic Dice: Moral Life in a Random World).

Tool Use

Tool use at one point was indeed long considered solely the providence of human ingenuity. But in fact non-human primates and birds commonly use tools, mainly to gather food. Chimpanzees, for example, regularly use stems as tools and can even pound stones with purpose, although they have never mastered flint-making. Chimps also use leaves as toilet paper. Egyptian vultures will search up to 50 yards for a rock to use to smash an ostrich egg. Green herons drop a small object onto the surface of the water to attract fish, which are fooled into thinking prey is nearby. The heron then turns the table and makes a meal of the unsuspecting fish.

If an elephant is unable to reach some itching part of his body with his trunk, the nearest tree often serves to relieve the problem. Just as often, however, an itchy elephant will pick up a long stick and give himself a good scratch with that instead. If one stick is insufficiently long he will look for one better suited to the task.

With what appears to be clear intention, elephants have been observed to throw or drop large rocks and logs on the live wires of electric fences, either breaking the wire or loosening it such that it makes contact with the earth, thus shorting out the fence. Elephants are undoubtedly clueless about electron flow, but have mastered the use of a tool to avoid its unpleasant consequences.

Some animals have graduated from tool use to tool fabrication. On the Galapagos Island, one of the many finch species made famous by Darwin uses a cactus spine as a spear to pry grubs from tree branches. Once this woodpecker finch has procured his shish kabob, he holds the skewer under foot to munch on the tasty snack. The bird will then carry the spine to another tree looking for the next meal. This finch, though, is not always happy with what nature provides, and improves the cactus spine for its purpose. One finch was observed shaping a forked spine into a single spike, and others shorten the spine to just the right length for probing and holding. Some finches can learn to use the tool by watching others do so.

These feats are noteworthy, but provide only examples of one animal using one tool for one purpose. Even more impressive is the learned use of a tool set. Chimpanzees in East and West Africa sequentially use four tools to obtain honey, all gathered together for that specific purpose. They start with a battering stick, then a use a chisel-like stick, followed by a hard-pointed stick, finally ending with a long slender flexible dip stick to pull out the honey. Each tool is used in a specific sequence, and sometimes made to order by clipping, peeling, stripping or splitting the wood to the desired specifications.

New Caledonian crows are famous for their ingenious tool fabrication, both in the wild and in captivity. Betty, a female crow, was filmed taking a piece of wire and trying to use it to grab some food at the bottom of a narrow tube. After several unsuccessful attempts, she removed the wire, fashioned a hook on the end, and subsequently used her new weapon to grab the food with ease. In the wild, these crows make an impressive variety of tools using a wide range of materials for diverse purposes. These birds actually shape different hooks for different tasks. This is tool use by any definition.

Culture

Until recently, the transmission of information through culture, or socially learned tradition, was thought to be found only among humans. Many considered this the "last stand" in proving human uniqueness. Culture seems to be clearly a uniquely human invention. In some human cultures, two people greeting each other will bow, where in others the two will shake hands. Some kiss once or twice on the cheek. Some societies prefer vodka over wine. Culture defines the context of our lives.

But in the 1950s, a few brave researchers demonstrated that culture was indeed found in other species, although this conclusion was resisted for several decades.

On the small Japanese island of Koshima, researcher Kinji Imanishi observed one day that a young female macaque named Imo took some precious sweet potatoes that were inconveniently covered with sand to a nearby stream to wash them off before eating them. That alone was interesting because the behavior had never before been seen. But more impressive, over time the entire colony adopted the innovation, and their descendants wash their potatoes even today because mothers continue to pass down the new tradition to the next generation.

Imo and her colony are not just an isolated example. In 1963, in the Nagano Mountains of Japan, another young female macaque named Mukubili waded into a hot spring to get some food that had been thrown in the water. The warm water was apparently a delightful respite from the bitter cold mountain air, and a few other young monkeys climbed in. Much as in human cultures, at first the behavior caught on only with the youth, but the old folks eventually got hip. The behavior is now well established in the entire troop, and has been passed on through many generations. In another example of youth-driven culture, some juveniles learned to roll and throw snowballs. That has no survival value, but is fun. The practice spread to others in the troop and is now a common play behavior.

The indisputable conclusion that other species have culture, however, is not the result of a few casual anecdotes or isolated case studies. Instead, presence of culture in other animals is seen as the result of carefully recorded observation by disparate scientists over many decades. In 1999, a group of researchers got together to compare notes from their years of field work with chimpanzees. Eventually they documented 39 examples of behaviors present in one group of chimps but not another, even when the groups lived in similar environments and had access to the same foods and potential tools. Cultural differences were seen in courting behavior, hunting strategies, tool use, social grooming, medicinal plant use and vocalizations. The behaviors were passed on from one generation to the other within a social group, and not reinvented anew with each generation. More recent work with orangutans has shown similar examples of culture and social learning. The difference in behaviors between groups was even more striking in orangutans, which interact with neighboring groups less than chimpanzees.
In the final blow to the notion that culture is somehow uniquely human, various forms of social learning within and between generations have been demonstrated beyond primates, including in birds, rats, elephants, whales (in addition to composing), and perhaps even in fish.

Get Over Ourselves

In defining our uniqueness, we are using a bizarre circular logic, working backward from a desired result. We look at all of our capabilities as humans, and then declare that those very sets of capabilities are what make us better than other animals, if not the image of god himself. But even when we give ourselves a big handicap by creating self-serving definitions that we know beforehand will prove advantageous, the categories of "uniquely human" talents are shrinking rapidly as we learn more about other animals and their adaptive behaviors. Characteristics previously considered special to our species have eventually been found, at least to some degree, and often with some humor, elsewhere in the animal kingdom. We see in the animal kingdom examples of impressive brain development, intelligence, self-awareness, empathy, social organization, even some ability in mathematics, as well as of course culture and tool use.

We are faced with the need to combat a fierce bias. People tend to believe that our species is superior to and separate from the animal kingdom, that we are the end point of the evolution of life on earth. That notion is not only false but extraordinarily dangerous. It is this hubris and arrogance that drives much of our most unsustainable behaviors. If we are special we need not respect natural resources put here by god for our use; nor must we protect animals we believe to be our inferiors. Yet biological reality on the ground is quite different from this species-centric view: human are nothing but a normal consequence of natural selection, and certainly not the pinnacle of evolution. We are nothing special, and bacteria are the proof. We desperately look for traits only we possess, like tool use and culture, only to be thwarted by animal ingenuity. It is time we got over ourselves and adopted a more humble attitude about our role in the biosphere. The chimps are watching as they sip their juice.