1
What Makes Us Human

An extraterrestrial zoologist observing our planet's wildlife a few hundred thousand years ago might well have been puzzled. The strange, soft-skinned, almost hairless primates that had emerged over the previous million years did not initially look like a good evolutionary bet, but they were doing incredibly well. Despite lacking the fangs, claws, or protective carapaces that other animals needed for safety, they were thriving. And they were developing skills and practices that the planet had never seen in any animal before. They lived in socially organized bands; nurtured and controlled fire to keep warm at night, deter predators, and cook food; planned and organized collaborative hunting; manufactured tools and weapons, sometimes with the aid of other tools; and developed practices like caring for the sick and burying the dead.

Their exploration of the planet grew steadily more ambitious. They populated not only the entire African continent but also the gigantic Eurasian land mass to the north and east. Ambrose Bierce quipped (before either of the twentieth century's great world wars) that although humans seem addicted to extermination of their own species as well as others, nonetheless humankind 'multiplies with such insistent rapidity as to infest the whole habitable earth and Canada.' As generations passed, they steadily became more and more expert at making complex tools, weapons, ornaments, pictures, sculptures, clothes, and boats. They had found a new way to pass knowledge and skills down the generations, completely transcending biological transmission of physical traits through genetic inheritance. We don't know when it happened: maybe 100,000 or 200,000 years ago, and possibly hundreds of thousands of years earlier; but at some time in the prehistoric past Homo sapiens (or quite possibly their immediate ancestors, Homo erectus) had developed language.

Today there are roughly 7 billion of us humans. We are the most important animals on earth, if only because of our unparalleled power to modify and perhaps destroy the planet's very capacity to support life. Animals of other species do all sorts of clever things, and alter their environments in many ways, but it's nothing comparable to what humans do. The complexity of human thought, behaviour, technology, and environmental modification is of an entirely different kind.

The aspects of human life that make our species unique depend in numerous ways on the special human ability to use language. For anyone who thinks it is important to understand what humans are like and why, a scientific comprehension of the capacity for language is essential. Linguistics is the scientific field devoted to achieving that understanding.

What Languages Are

What exactly do I mean by a 'language'? In a sense the whole discipline of linguistics is devoted to a long-term project of properly answering that question by giving a full theory of the nature of human languages, the things they share, and the ways in which they differ. But as a rough starting point, human languages are structured systems for making articulated thoughts fully explicit both internally (mentally) and externally (in a form perceptible to other humans), and linguistics studies all components of such systems, together with the ways in which they are used.

It is extremely common for people to take 'language' and 'communication' to be the same thing. In this book, however, they are never equated. They are clearly distinct in that each is found in the absence of the other. Most communication, even between humans, has nothing to do with language (think of frowning, winking, shrugging, grinning, eyebrow-raising, caressing, or glaring). Some of it isn't even voluntary (blushing, limping, trembling). And conversely, lots of the use we make of language involves no communication in any reasonable sense. Think of someone silently planning a speech that they will never give, or checking a document for wording errors, or silently reflecting on whether likely has exactly the same meaning as probable.

All animals communicate, but only humans have languages in the sense that is relevant for this book. That doesn't mean I disapprove of talk about the language of music, flowers, art, or architecture. It's just that when we get down to brass tacks, these metaphorical extensions of the term 'language' should be ignored, because they will only encourage confusion. When I talk about language I will never be referring to concertos, carnations, collages, or cupolas.

Let me get just a little more specific about languages. The systems that linguists study connect virtually unbounded numbers of sentence meanings (arbitrarily complex thoughts) to external realizations, in a medium-independent way (a given sentence can be presented in either written or spoken form). Thus the subject matter for linguists extends from the study of the ways in which speech sounds are made (phonetics) to the study of how meaningful sentences are used in context to convey implicit meanings (pragmatics). Sentences can instruct or query or exhort or signal emotion, and crucially they can express claims, either true and false, and can be used not only externally, for communication or easing of social interaction, but also internally, for reasoning.

Consider a specific sentence like Everybody seems to be leaving. You don't need to utter it aloud; you can just think it. You can also privately and internally figure out its logical consequences; for example, it implies that apparently nobody is planning to stay. It could provide grounds for thinking that pretty soon the place will be empty. You could make it audible by saying it out loud, or make it visible by writing it down (in lower-case letters, or capital letters, or for that matter in Morse code), but you don't have to. It's still a sentence. And crucially, you can do any or all of these things without being in a situation where the statement could conceivably be true. The sentence doesn't just pop up involuntarily in your mouth when everyone does actually seem to be leaving. You can consider the sentence and grasp its meaning whether it's true right now or not.

Other animals show no signs of being able to do anything of this sort. Various cases have been reported of animals (from monkeys to prairie dogs) that produce warning cries when predators are spotted, and make different sounds for different types of predators - one call for a snake on the ground, another for an eagle in the air, and so on. But they produce these calls involuntarily when a predator is noticed, and they never use the calls for anything else. It's nothing like what you, as a speaker of a human language, can do. You can wonder aloud about who would win in a fight between an eagle and a snake, without there being any eagles or snakes in the vicinity. No monkey can do that.

That's not to say animals are unintelligent. Dogs, in particular, have a wonderful social ability: more than any other animal, they use their intelligence to attempt to figure out what we're paying attention to and what we might be planning. They have admirable memory powers, too. A border collie named Rico (1994-2004) was trained to fetch any of about 200 specific named toys on command. In fact, if given an unfamiliar name ('Fetch the glimp!') Rico would run and fetch a previously unnamed toy, if there was one, assuming the new word was its name (an apparent word-learning behaviour known as 'fast mapping').

However, this was entirely the result of intensive training and supplying of rewards. Rico only responded to the owner's fetch commands, and responded solely by running to fetch the named toy. Everything was task-based and in the moment. As the psycholinguist Paul Bloom noted, humans can use a noun like sock in other ways than by running to the bedroom to fetch one in order to get a snack as a reward. Complaining about having lost one, for example, or asking whether it's time to go out and buy some. That kind of word use is the province of humans alone. And it forms just one small part of the array of human abilities that linguistics seeks to understand.

Languages of the World

About 7,000 distinct languages are in use among human communities today. I say 'about', because making the number precise is not really possible. No sharp scientific distinction can be drawn between two slightly different forms of one language and two distinct but very closely related languages. The distinctions are only assumed to be really clear where social and political facts draw suitable lines.

We take Flemish and Dutch to be different languages, because of the Belgium-Netherlands border, though they're extremely similar. We imagine that people on either side of the Netherlands-Germany border speak different languages, when in fact the local rural dialects on either side hardly differ at all. Everyday Urdu and Hindi are almost identical except for minor pronunciation differences (though they diverge in learned and culture-specific vocabulary), but their Pakistani and Indian speakers very firmly insist that they are different languages. This suggests we may be overcounting languages.

But in other ways we may be undercounting. We take lowland Scots to be just English with a Scottish accent, but linguists generally regard Scots and English...