The Problem of Non-Shared Environment in Behavioral Genetics
The role of non-shared environment (NSE) in the development of psychological traits is usually comparable with that of the genotype. However, no specific factors of NSE with significant impact on such traits have been discovered so far. We propose that the current failures in understanding the origin of NSE are at least partly due to the fact that behavioral genetics has left out one of the key sources of phenotypic variation. This source is the intrinsic stochasticity of molecular processes underlying individual development. At the critical stages of ontogeny, even minor fluctuations in gene expression or gene-product functioning can remarkably affect the phenotype; this role is experimentally proved in multiple model organisms. In the present paper, several mechanisms of molecular stochasticity, which could affect the development of psychological traits, are discussed. We propose to distinguish external NSE (any external differences) and internal NSE (intrinsic molecular stochasticity). Available data indicate that the impact of external NSE is likely to be low, which makes the presumptive role of internal NSE rather decisive. If our assumption is true, the paradigm of behavioral genetics should be revised, and comprehensive analysis of molecular stochasticity during individual development is strongly required.
KeywordsBehavioral genetics Psychological traits Non-shared environment Molecular stochasticity Phenotype formation
The authors are grateful to anonymous reviewers for their very helpful commentaries and to Maria Lebedeva for her kind assistance in preparation of the text.
This study was funded by Russian Foundation for Basic Research (Grant 15-04-05579).
Compliance with Ethical Standards
Conflict of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- Allis CD, Jenuwein T, Reinberg D, Caparros M-L (2007) Epigenetics. Cold Spring Harbor Laboratory Press, New YorkGoogle Scholar
- Astauroff BL (1930) Analyse der erblichen Stoerungsfaelle der bilateralen symmetrie im Zusammenhang mit der selbstaendigen variabilitaet aenlicher Strukturen. Z indukt Abstamm Vererb 55(3):183–262Google Scholar
- Bar-Yam Y (1997) Dynamics of complex systems. Addison-Wesley, ReadingGoogle Scholar
- Bourgeois P, Bolcato-Bellemin A-L, Danse J-M, Bloch-Zupan A, Yoshiba K, Stoetzel C, Perrin-Schmitt F (1998) The variable expressivity and incomplete penetrance of the twist-null heterozygous mouse phenotype resemble those of human Saethre–Chotzen syndrome. Hum Mol Genet 7:945–957. https://doi.org/10.1093/hmg/7.6.945 CrossRefPubMedGoogle Scholar
- Changeux J-P, Garey L (1997) Neuronal man: the biology of mind. Princeton University Press, New JerseyGoogle Scholar
- Deater-Deckard K, Pike A, Petrill SA, Cutting AL, Hughes C, O’Connor TG (2001) Nonshared environmental processes in social-emotional development: an observational study of identical twin differences in the preschool period. Dev Sci 4:F1–F6. https://doi.org/10.1111/1467-7687.00157 CrossRefGoogle Scholar
- Dirac PAM (1935) The principles of quantum mechanics, 2nd edn. The Clarendon Press, OxfordGoogle Scholar
- Falconer DS, Mackay TF (1996) Introduction to quantitative genetics, 4th edn. Longman, EssexGoogle Scholar
- Feldmeyer D, Lübke JHR (eds) (2010) New aspects of axonal structure and function. Springer, BerlinGoogle Scholar
- Frank-Kamenetskii DA (1967) Diffusion and heat transfer in chemical kinetics. Nauka, Moscow [in Russian]Google Scholar
- Galton F (1875) The history of twins as a criterion of the relative powers of nature and nurture. Fraser’s Mag 12:566–576. https://doi.org/10.1093/ije/dys097 Republished as: Galton F (2012) The history of twins as a criterion of the relative powers of nature and nurture. Int J Epidemiol 41:905–911CrossRefGoogle Scholar
- Goswami A (2012) The physicists’ view of nature part 2: the quantum revolution. Springer Science & Business Media, BerlinGoogle Scholar
- Griffiths AJF, Wessler SR, Carroll SB, Doebley J (2010) An introduction to genetic analysis, 10th edn. WH FreemanGoogle Scholar
- Jablonka E, Lamb M (2005) Evolution in four dimensions: genetic, epigenetic, behavioral, and symbolic variation in the history of life. MIT Press, CambridgeGoogle Scholar
- Koshland EE Jr (1984) Individuality in bacteria and its relationship to higher species. In: Fox SW (ed) Individuality and determinism: chemical and biological bases. Plenum, New York, pp 1–31Google Scholar
- Kozlenkov A, Wang M, Roussos P, Rudchenko S, Barbu M, Bibikova M, Klotzle B, Dwork AJ, Zhang B, Hurd YL, Koonin EV, Wegner M, Dracheva S (2016) Substantial DNA methylation differences between two major neuronal subtypes in human brain. Nucleic Acids Res 44:2593–2612. https://doi.org/10.1093/nar/gkv1304 CrossRefPubMedGoogle Scholar
- Kulkarni G, Xu Z, Mohamed AM, Tang X, Limerick G, Wadsworth WG (2013) Experimental evidence for UNC-6 (netrin) axon guidance by stochastic fluctuations of intracellular UNC-40 (DCC) outgrowth activity. Biol Open 2:1300–1312. https://doi.org/10.1242/bio.20136346 CrossRefPubMedPubMedCentralGoogle Scholar
- Landau LD, Lifshitz EM (1965) Quantum mechanics. Pergamon Press, OxfordGoogle Scholar
- Loehlin JC (1992) Genes and environment in personality development. Sage Publications, Newburg ParkGoogle Scholar
- Luo C, Keown CL, Kurihara L, Zhou J, He Y, Li J, Castanon R, Lucero J, Nery JR, Sandoval JP, Bui B, Sejnowski TJ, Harkins TT, Mukamel EA, Behrens MM, Ecker JR (2017) Single-cell methylomes identify neuronal subtypes and regulatory elements in mammalian cortex. Science 357:600–604. https://doi.org/10.1126/science.aan3351 CrossRefPubMedPubMedCentralGoogle Scholar
- McCrae RR, Costa PT Jr, Ostendorf F, Angleitner A, Hrebícková M, Avia MD, Sanz J, Sánchez-Bernardos ML, Kusdil ME, Woodfield R, Saunders PR, Smith PB (2000) Nature over nurture: temperament, personality, and life span development. J Person Soc Psychol 78:173–186. https://doi.org/10.1037/0022-35220.127.116.11 CrossRefGoogle Scholar
- Plomin R, DeFries JC, Knopik VS, Neiderheiser J (2013) Behavioral genetics. Macmillan, PalgraveGoogle Scholar
- Ridley M (2003) Nature via nurture: genes, experience, and what makes us human. Harper Collins Publishers, New YorkGoogle Scholar
- Ruvinsky A (2016) Genetics and Randomness. CRC Press, Boca RatonGoogle Scholar
- Schroeder M (1991) Fractals, chaos, power laws: minutes from an infinite paradise. WH Freeman, New YorkGoogle Scholar
- Strunnikov VA, Vyshinskiy IM (1991) Realisational variation in silk vorm. In: Shumny VK, Ruvinsky AO (eds) Problems in genetics and the theory of evolution. novosibirsk. pp 98–114 [in Russian]Google Scholar
- Tikhodeyev ON (2013) Classification of variability forms by key factors determining the phenotype: traditional views and their modern revision. Ekologicheskaya Genetika 11(3):79–92. [in Russian]Google Scholar
- Tvorogova VE, Gurina AA, Tkachenko AA, Lebedeva MA, Tikhodeyeva MY, Tikhodeyev ON (2017) Stochastic variation of flower structure in Trientalis europaea L. Wulfenia 24:61–74Google Scholar
- Van Kampen NG (2007) Stochastic Processes in Physics and Chemistry. 3 rd ed. Elsevier, AmsterdamGoogle Scholar
- Vogt G (2015) Stochastic developmental variation, an epigenetic source of phenotypic diversity with far-reaching biological consequences. J Biosci 401–446. https://doi.org/10.1007/s12038-015-9506-8
- Von Wrigh GH (1974) Causality and determinism. Columbia University Press, New YorkGoogle Scholar
- Waddington CH (1962) New patterns in genetics and development. Columbia University Press, New YorkGoogle Scholar