Abstract

Culture–gene coevolution proposes that biological and cultural processes mutually shape human behavior across generations. This review examines how individualistic and collectivist cultural systems may emerge through interactions among environmental pressures, neural plasticity, and genetic variation. Particular attention is given to pathogen stress theory, medial prefrontal cortex (mPFC) activation patterns, serotonin transporter polymorphisms (5- HTTLPR), oxytocin receptor genes (OXTR), and dopamine-related genes such as DRD4. The paper also incorporates comparative analysis using publicly available transcriptomic datasets from the Human Brain Transcriptome and Aging databases hosted through GeneNetwork. Three datasets associated with serotonergic and stress-related neural pathways were examined to compare transcriptomic variability across brain tissues relevant to social cognition and emotional regulation. Findings from neuroscience and cultural psychology suggest that collectivist cultures may provide adaptive social buffering for genetically stress-sensitive populations, while individualistic cultures may favor exploratory and novelty-seeking behavioral phenotypes. Epigenetic mechanisms further demonstrate how parenting styles and cultural environments influence gene expression without altering DNA sequences. Additional neurophilosophical perspectives concerning emotion regulation, free will, mindfulness, and psychopathology are integrated through recent interdisciplinary scholarship. The paper also discusses methodological limitations, ethical concerns regarding biological determinism, and the risks of cultural stereotyping. Finally, a personal reflection highlights the lived experience of navigating both individualistic and collectivist social systems. Overall, this review argues that human behavior cannot be explained solely by genes or culture alone, but rather through the dynamic interaction between biology, environment, and cultural learning.