The etiology of schizophrenia and the origin of language: overview of a theory.
Schizophrenia is present in all human populations with approximately the same incidence. Why does such illness persist given that it is associated with a reproductive disadvantage? What is the balancing advantage? A possible explanation is linked to human language. According to this hypothesis schiz...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2003
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| Summary: | Schizophrenia is present in all human populations with approximately the same incidence. Why does such illness persist given that it is associated with a reproductive disadvantage? What is the balancing advantage? A possible explanation is linked to human language. According to this hypothesis schizophrenia occurs as a manifestation of genetic diversity associated with language--the function by which Homo sapiens has separated from other primate species. Language originated by a genetic mutation that allowed the cerebral hemispheres to develop with a degree of specialization (or lateralization) reflected in cerebral asymmetries. Individuals with schizophrenia show lesser structural and functional brain asymmetries than the population as a whole, and this finding can be interpreted as a delay, or failure in, establishing hemispheric dominance for language. We review recent evidence supporting this theory. |
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