The molecular genetic architecture of human personality: beyond self-report questionnaires

• Published in: Molecular psychiatry Vol. 11; no. 5; pp. 427 - 445
• Main Author: Ebstein, R P
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.05.2006; Nature Publishing Group
• Subjects: Altruism; Animals; Behavioral psychophysiology; Behavioral Sciences; Biological and medical sciences; Biological Psychology; Dopamine; Dopamine D4 receptors; feature-review; Fundamental and applied biological sciences. Psychology; Gene polymorphism; Genetics; Genomics; Haplotypes; Humans; Medicine; Medicine & Public Health; Neuroimaging; Neurosciences; Neurosis; Neurotransmission and behavior; Novelty; Personality; Personality - genetics; Personality Tests; Personality traits; Personality. Affectivity; Pharmacotherapy; Polygenic inheritance; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Questionnaires; Receptors, Dopamine D4 - genetics; Self report; Self-Assessment; Serotonin; Serotonin Plasma Membrane Transport Proteins - genetics; Serotonin transporter; Social sciences; Temperament - physiology; Jerusalem Israel; Israel; molecular genetics; dopamine d4 receptor (DRD4); serotonin transporter (SLC6A4); personality; review; temperament; Human; D4 Dopamine receptor; Questionnaire; Self evaluation; Psychometrics; Personality; Review; Temperament; Serotonin transporter; Genetics
• ISSN: 1359-4184; 1476-5578
• DOI: 10.1038/sj.mp.4001814

Molecular genetic studies of personality began with two high impact papers in 1996 that showed provisional associations between the dopamine DRD4 exon III repeat region and Novelty Seeking/Extraversion. These first two reports were shortly followed by an investigation linking Neuroticism/Harm Avoidance with the serotonin transporter ( SLC6A4 ) promoter region polymorphism (5-HTTLPR). In the ensuing decade, thousands of subjects have been studied for association between these genes and personality, assessed by using self-report questionnaires, with erratic success in replication of the first findings for Novelty Seeking ( DRD4 ) and Harm Avoidance (5-HTTLPR). Small effect sizes characteristic of non-Mendelian traits, polygenic patterns of inheritance and true heterogeneity between studies confound attempts to reach a consensus regarding the role of common polymorphisms in contributing to personality domains. Nevertheless, the current state of personality genetics is far from being bleak. Several new paradigms especially functional neuroimaging or ‘imaging genomics’ have strengthened the connection between 5-HTTLPR and anxiety-related personality traits. The demonstrations that early environmental information can considerably strengthen and even uncover associations between genes and behavior (Caspi's seminal studies and more recently the demonstration that early environment impacts on DRD4 and Novelty Seeking) are notable and herald a new era of personality genetics. Finally, consideration of the broader phenotypic expression of common polymorphisms (e.g. the ‘social brain’, altruism, etc.) and the use of new experimental paradigms including neurophysiological, neuropsychological and computer games that go beyond the narrow self-report questionnaire design will enable a deeper understanding of how common genetic polymorphisms modulate human behavior. Human personality, defined by Webster as the quality or state of being a person or the complex of characteristics that distinguishes an individual, surely requires a more encompassing view towards understanding its complex molecular genetic architecture.