These are excerpts and elaborations from my book "The Nature of Consciousness"
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Co-evolution The US anthropologist Ralph
Holloway ("The evolution of the
human brain", 1967) claimed already in the 1960s that brain reorganization
must have preceded brain evolution: ancient hominids still had a small brain
like apes but could already do things that an ape's brain couldnt do like full
bipedalism. He posited a form of positive feedback between mental evolution
and bodily evolution. The US anthropologist
Terrence Deacon believes that language and the brain co-evolved. They evolved
together influencing each other step by step. In his opinion, language did not
require the emergence of a language organ. Language originated from symbolic
thinking, an innovation that occurred when humans became hunters because of the
need to overcome the sexual bonding in favor of group cooperation. Both the brain and language
evolved at the same time through a series of exchanges. Languages are easy to
learn for infants not because infants can use innate knowledge but because
language evolved to accommodate the limits of immature brains. At the same
time, brains evolved under the influence of language through the Baldwin effect. Language caused a reorganization of the
brain, whose effects were vocal control, laughter and sobbing, schizophrenia,
autism. Deacon rejects the idea of a universal
grammar ā la Chomsky. There is no innate
linguistic knowledge. There is an innate human predisposition to language, but
it is due to the co-evolution of brain and language and it is altogether
different from the universal grammar envisioned by Chomsky. What is innate is a
set of mental skills (ultimately, brain organs) which translate into natural tendencies,
which translate into some universal structures of language. Another way to describe this
is to view language as a "meme". Language is simply one of the many
"memes" that invade our mind. And, because of the way the brain is,
the meme of language can only assume such and such a structure: not because the
brain is pre-wired to such a structure but because that structure is the most
natural for the organs of the brain (such as short-term memory and attention)
that are affected by it. Chomsky's universal grammar is an outcome of the evolution of language in our
mind during our childhood. There is no universal grammar in our genes, or,
better, there are no language genes in our genome. The secret of language is
not in the grammar, but in the semantics. Language is meaningful. Deacon envisions a hierarchy of levels
of reference (of meaning), that reflects the evolution of language. At the top
is the level of symbolic reference, a stable network of interconnected
concepts. A symbol does not only refer to the world, but also to other symbols.
The individual symbol is meaningless: what has meaning is the symbol within the
vast and ever changing semantic space of all other symbols. At lower levels,
Deacon envisions less and less symbolic forms of representation, which are also
less and less stable. At the lowest, most fluctuating level of the hierarchy
there lie references that are purely iconic and indexical, created by a form of
learning that is not unique to language (in fact, it is widespread in all
cognitive tasks). The lower levels are
constrained by what humans can
experience and learn, which is constrained by innate abilities. The higher level,
on the other hand, is an emergent system due to the interaction among linguistic
agents. According to US
neuroscientist Rhawn Joseph, one of the youngest parts of the brain, the inferior parietal lobe of
the left hemisphere, enabled both
language, tool making and art itself. It enabled us, in other words, to create
visual symbols. It also enabled us to create verbal symbols, i.e. of writing. The inferior parietal lobe
allows the brain to classify and label things. This is the prerequisite to
forming concepts and to abstracting in general. Surprisingly, this is also the same organ that enables meaningful
manual gesturing (a universal language, that it is also shared with many
animals). Thus the evolution of writing is somehow related (neurally speaking)
to manual gesturing. The inferior parietal lobe was one of the last organs of
the brain to evolve, and it is still one of the last organs to mature in the
child (which explains why children have to wait for a few years before they can
write and do math). This lobe is much more
developed in humans than in other animals (and non-existent in most). The
neurons of this lobe are somewhat unique in that they are multimodal: they
are capable of simultaneously processing different kinds of inputs (visual,
auditory, movement, etc). They are also massively connected to the neocortex,
precisely to three key regions for visual, auditory and somatosensory processing. Their structure and location makes them
uniquely fit to handle and create multiple associations. It is probably this
lobe that enables us to understand a word as both an image, a function, a name
and many other things at the same time. Joseph claims that the emotional
aspect of speaking is the original one: the motivation to speak comes from the
limbic system, the archaic part of the brain that deals with emotions, and that
we share with other mammals. The limbic system embodies a universal language
that we all understand, a primitive language made of calls and cries. Each
species has its own, but within a species all members understand it. Joseph
believes that at this stage the vocal hemisphere is the right one. Only
later, after a few months, does the left hemisphere impose structure to the
vocalizing and thus become dominant in language. The US evolutionary psychologist Geoffrey Miller believes that the human mind was largely molded by sexual selection and is therefore mainly a sexual ornament. Culture, in general, and language, in particular, are simply ways for males and females to play the game of sex. When language appeared, it quickly became a key tool in sexual selection, and therefore it evolved quickly. Darwin had already speculated that
language may have evolved through sexual selection(as a means to impress sexual
mates). Miller agrees, finding that the usual explanation (that language helps a
group trade key information) is only a small piece of the puzzle (individuals,
unless they are relatives, have no motivation to share key information since
they are supposed to compete). Even more powerful is the
evidence that comes from observing the behavior of today's humans: they compete
to be heard, they compete to utter the most sensational sentences, they are
dying to talk. Miller also mentions anatomical
evidence: what has evolved dramatically in the human brain is not the hearing
apparatus but the speaking apparatus. Miller believes that language, whose
intended or unintended effect is to deliver knowledge to competitors, must also
have a selfish function, otherwise it would not have developed: individuals who
simply delivered knowledge to competitors would not have survived. On the other
hand, if language is a form of sexual display, then it makes sense that it
evolved rapidly, just like any other organ (bull horns or peacock tails) that
served that function. It is unique to humans the same way that the peacocks
tail is unique to peacocks. It is pointless to try and teach language to a
chimpanzee the same way that it is pointless to expect a child to grow a
colorful tail. Back to the beginning of the chapter "The History of Language: Why We Speak" | Back to the index of all chapters |
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