What has homo sapiens really bought at the cost of schizophrenia?
Evolutionism seen through a philosophy of language

Antonino Pennisi, Alessio Plebe(*) and Alessandra Falzone
Dept. of Cognitive Science, University of Messina, Italy

(*) aplebe@unime.it

One of the most intriguing positions in the evolution debate is that
schizophrenia is the price that Homo sapiens pays for language.  Language and
schizophrenia are both unique traits of the human species and are equally
distributed around the world.  Crow (Crow, 1996, 2000) (Crow and Kim, 2000)
proposed a common origin, back in a genetic mutation able to alter the
anatomical and functional hemispheric balance, fixed in the sexual X chromosome
about 100,000 years ago.  Several facts support his thesis: the distribution of
handedness among the normal and the psychotic population (Gur, 1977), the dating
of the supralaryngeal vocal tract specialization (Lieberman, 1975, 1991), and
the finding of FOXP2 as a putative genetic correlate (Enard et al., 2002).
However, there are two drawbacks to Crow's theory, one concerning the evolution
history and another the linguistic characterization of schizophrenia.  On the
first point, while schizophrenia and language are human specific, lateralization
is not; on the contrary it is widespread among current species and through
paleontological ages (Rogers and Andrew, 2002).  Concerning the second point,
the linguistic deficits connected to schizophrenia are highly arguable.  If the
schizophrenic patient were really deprived of the hemispheric specialized
processes, his linguistic performances - especially syntax - should suffer as a
result.  This is not the case.  Linguistic studies (Irigaray, 1985)(Pennisi,
1998), have shown that some schizophrenic patients even exhibit enhanced
syntactic capabilities.  They not only preserve normal articulatory performances
but are especially able in morphological constructions (neologisms and
paralogisms built on formally correct monemes) and discourse constructions (oral
and verbal fluency, precise syntactic linkage and ordering).  Thanks to such
abilities, they can build complete "neolanguages".  Extended linguistic analysis
reveals that even verbigerations retain organization of meaning intact.  So,
what is the specific language pathology of schizophrenia? As Crow himself noted
(Crow, 2000), the original traits of schizophrenia are a) internal voices; b)
the theft of thought, and c) the escape of ideas.  All seems to depend on a lost
identification of the linguistic self.  In other words, defects seem to seat at
the upper cognitive level responsible for the self-identification mechanisms,
showing, when corrupted by schizophrenia, a "loss of natural evidence"
(Blankenburg, 1971).  Several EPR studies support this view (Rockstroh et al.,
2001).  Therefore the schizophrenic deficit seems to be a weakness in the
ontological rooting of language in reality more than a defect in its formal
mechanics.  If this is the case, Crow's slogan can be rephrased as:
"Schizophrenia is the price that Homo sapiens pays for the capability of
language to generate existential semantics".  And not for articulatory and
syntactic capabilities.  Still believing in a common root for language and
schizophrenia, lateralization and the emergence of a linguistic consciousness
now appear far too distant for an explanation.  Too distant in time, from the
origin of the brain hemispheric specialization to the evolution of a
language-centered form of life.  But too distant in ontogenesis as well, from
the sole biological inheritance to the fundamental role of the cultural
environment in the emergence of language functionality.  Janet's "fonction du
reel" (Janet, 1903), can only emerge from the binding between the natural and
the historical aspects of language, something which is missing from
schizophrenic language. 

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Enard W., Przeworski, M., Fisher, S.E., Lai, C.S.L., Wiebe, V.,  Kitano, T.,
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Rockstroh, B., Kissler, J., Mohr, B., Eulitz, C., Lommen, U., Wienbruch, C.,
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Janet, P. (1903). Les obsessions et la psychastenie, Paris, Alcan, vol II, 433.