Schizophrenia and Human Self-Domestication: An Evolutionary Linguistics Approach

Area of Science:

• Evolutionary biology
• Neuroscience
• Genetics

Background:

• Schizophrenia (SZ) is a complex neurodevelopmental disorder with persistent social, cognitive, and language deficits.
• The high, stable incidence of SZ across human populations suggests deep evolutionary roots.
• Current understanding of SZ's multifactorial etiopathogenesis, involving genetic and environmental factors, remains incomplete.

Purpose of the Study:

• To explore the hypothesis that SZ pathophysiology is linked to human self-domestication.
• To investigate the role of the neural crest and associated genes in SZ.
• To examine the connection between domestication syndrome traits and SZ.

Main Methods:

• Comparative analysis of human traits with mammalian domestication syndromes.
• Examination of genes associated with domestication, neural crest development, and SZ.
• Analysis of gene expression profiles in brain regions critical for language in SZ patients.

Main Results:

• Individuals with SZ exhibit more pronounced domesticated traits morphologically, physiologically, and behaviorally.
• Genes implicated in domestication and neural crest function constitute approximately 20% of SZ candidate genes.
• Many of these genes show altered expression in the brain areas of SZ patients involved in language processing.

Conclusions:

• Schizophrenia may represent an aberrant developmental pathway for human language faculty.
• The findings suggest a partial contribution of altered genes related to the domestication syndrome and neural crest to SZ.
• This perspective offers a novel framework for understanding the evolutionary underpinnings of schizophrenia.