Now –– it seems like we are going into the Twighlight Zone. Or beyond the world of what is scientifically possible to measure.
“Personality” is influenced by genetic, epigenetic, and environmental factors –– as well as being associated with mental health. However, the underlying genetic determinants are largely unknown. In the attached report, authors performed a meta-analysis of genome-wide association studies (GWAS), looking at phenotypes such as “being an extrovert“, “neurotic“, “openness to new ideas“, schizophrenia, bipolar disorder, and attention-deficit-hyperactivity disorder (ADHD).
Cohort sizes in the study [attached] ranged from N = 123,132 to 260,861. Authors identified six genetic loci –– including five novel loci –– that were significantly associated with these personality traits. Authors performed principal component analysis (PCA) to extract major dimensions underlying genetic variations among five personality traits and six psychiatric disorders (N = 5,422–18,759). Among these GWAS-significant loci, extrovertism was associated with variants in WSCD2 and near PCDH15, and neuroticism with variants on chromosome 8p23.1 and in L3MBTL2. The first genetic dimension separated personality traits and psychiatric disorders –– except that “neuroticism” and “openness to experience” were clustered with the psychiatric disorders.
High genetic correlations were found between “extrovertion” and ADHD, and also between “openness” and “schizophrenia” and “bipolar disorder.” The second genetic dimension was closely aligned with “extrovertism–introvertism” and grouped “neuroticism” with internalizing psychopathology such as mental depression or anxiety. Although these GWAS are academic exercises of general interest, clearly these findings will (highly likely) never be of any clinical utility (i.e. designing of drugs to target specific genes or gene products).
Nat Genet Jan 2o17; 49: 152-156