This is my notes from the second part of the Pinker and Bloom
article.
It has been argued that if language was an adaptation it
would be better and more different than it actually is
(Piattelli & Palmanni). However Pinker and Bloom argue that
natural selection cannot reach perfection because there is
always a conflict of interests. For example in language, the
speaker wants to use the minimum number of words to get his
message across whereas the hearers want to understand the
message using the smallest amount of effort. so therefore a
code is needed which is a compromise between the two demands.
Pinker and Bloom argue state that any communication system
need to have the same parity setting. This standardization
is much more important than any other adaptive feature. some
constraints could have been selected, simply because they
linked with parts of a standardized code. Each member of a
community needs to learn in the same way as other members.
There are many possible rationale for any form-meaning
pairing, we we apply rationale to predict the form from the
meaning. The problem is the different rationales can impress
different speakers. These individual differences need to be
forgotten to communicate. Pinker & Bloom suggest that the
structure of grammar could come about as every child comes to
this conclusion.
In argument of Gould's theory, Pinker and Bloom argue that
courtship behaviour must be stereotyped to be understood and
therefore must be resistant to change in life. A code like
this which is standardized must be hardwired into device and
not acquired. Therefore universal grammar came about from
evolution because our species all needed to understand the
same initial rules so that we would be able to understand
each other.
Pinker and Bloom then go on to say that language acquisition
must originally have been a gradual process where each step
was small enough to have been produced by a random mutation
or recombination and each stage must have given the speaker a
reproductive advantage.
Lieberman believes that detailed genetically transmitted UG
which is identical in every human is outside the range of
biological plausibility. P & B argue that natural
selection selected out variation especially in adaptively
complex mechanisms such as language. Also, there is
variation in grammatical ability as we al have different
styles due to the accessibility and genetic differences.
This view is supported by evidence that there are genetically
transmitted syndromes causing language deficits.
Geschwind asked "how was a mutation successful if the people
around could not understand them?"
Argument: a mutation is likely to be shared by other people in
family so other kin could probably understand them, then
the rule could be elaborated on so that others outside the
family could understand it. Also comprehension abilities do
not have to be linked directly with production abilities e.g
we cannot speak in Shakespeare style language but we can
understand it.
P * B also explain the BALDWIN EFFECT:- If it takes cognitive
effort to decode information, it then causes pressures for
evolution to form neural mechanisms which would make decoding
such information more automatic.
Many linguistic rules are all or none operations so how could
they have been formed by a gradual process, as they can only
be understood as a whole? However, P * P argue that not
everything has to evolve in a continuous sequence. No single
mutation could have formed universal grammar but could have
led to a parent with a n-rule grammar having an offspring
with a n-rule + 1 grammar.
In answer to Bates's argument that UG was either endowed by a
single creator or by a single mutation e.g. like the Big
Bang, P & B believe that genetic change could be caused by a
nonlinguistic system popping up in a system responsible for
communication. This mechanism would be used to encode and
decode information and selective forces could then shape them
so that they were specific to language.
Hinton and Nowlan showed through computer stimulation that
learning can guide evolution. Therefore the vast number of
human languages could be due to learning mechanisms existing
prior to language and then evolving through time to create
differences.
Premack state that "human language is an embarrassment for
evolutionary theory because it is vastly more powerful than
one can account for in terms of selective fitness." This
view supports common belief that only humans in modern
societies need to use the sophisticated machinery of language.
However language is not just important in industrial
societies. Modern huntergatherers have a folk biology where
knowledge about ecology and wild plants is passed through
generations. This information allows the Kung San tribe to
enjoy a nutritionally complete diet in conditions where it
would otherwise be impossible. Therefore the survival of
these people is dependent on the acquired knowledge gained
through language. They do not have learn about whether a
fruit is poisonous by trial and error.
The Kung sam community depends on cooperative efforts for
survival. There are no conflicts within groups as all
disputes are resolved through negotiation. The reliance on
communication for survival puts great importance on ability
to convey oneself easily and clearly and to embed
propositions within others to state beliefs about others.
In a groups everyone is competing for attention and
sympathy, therefore there is an advantage if you can engage
a person's interest and persuade listeners to agree with your
opinion. Tribal chiefs are gifted orators and also highly
polygamous and therefore their linguistic skills are carried
into the next generation easily.
The social value of language is important in evolution .
People have always cooperated for each others food and
safety, causing a series of prisoners dilemmas to arise.
Cooperation could either benefit all participants or make
them vulnerable to invasion by cheaters, who want the best
selfish outcome.
To sustain a cooperative lifestyle, memory and ability to
enforce social constraints is needed. It is also
advantageous in these prisoner's dilemmas for cheaters to be
able to fool people into believing they have paid a costs or
taken a benefit. This ability , in turn puts pressure on
ability to detect subtle signs of cheating and puts pressure
on cheaters to cheat in less detectable ways. This pattern
results in a cognitive arms race resulting in a rapid
evolution of structure and abilities. P & B give this as a
reason for explaining why humans have enlarged frontal
lobes.
Our use of persuasion and argument to frame an offer so that
it appears to present maximal benefit and minimum cost has
evolved because of our competition with others for
resources. Also our ability to learn about other peoples
desires and obligations has increased our fitness and
therefore evolved. Language even in primitive societies has
played a key role in reproductive success.
Biologists have argues that as chimpanzees share 99% of
humans genetic material they should show signs of language
and as biological ability cannot evolve form nothing, we
should be able to find nonlinguistic abilities in humans with
the same characteristics as grammar. For example, motor
programs could be preadaptation of syntactic rules.
However, signing abilities of apes show no significant
resemblance to human language and differs significantly with
signaling in deaf children. It could be said that as
language is discontinuous with primate abilities that it did
not evolve through natural selection. P & B argue that both
humans and chimps have evolved in different directions since
the split from a common ancestor 3.5 - 5 million years ago.
The 1 % difference in genetic material is actually 40,000
base pairs and even a one pair difference can result in a
difference in overall function. Therefore P & B state that a
1% difference in genetic material can cause many differences
in function.
Basically, Pinker and Bloom believe that language is a
complex design as it communicates propositional structures and
the only proved explanation for complex design is natural
selection. The flaw in their article is that they do not
look at how universal grammar evolved instead they look at
the broader area of language.
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