Research Review: The shared environment as a key source of variability in child and adolescent psychopathology

• Published in: Journal of child psychology and psychiatry Vol. 55; no. 4; pp. 304 - 312
• Main Author: Alexandra Burt, S.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01-04-2014; Blackwell
• Subjects: Adolescent; Adolescents; Adult and adolescent clinical studies; Adulthood; Adults; Biological and medical sciences; Child; Child & adolescent psychiatry; Child clinical studies; Children; Environment; Environmental aspects; Environmental Influences; Error of Measurement; externalizing; Family - psychology; genetically informed studies; genetics; Humans; Individual Differences; internalizing; Medical sciences; Mental Disorders - etiology; Mental Disorders - genetics; Mental Disorders - psychology; Meta Analysis; Miscellaneous; Psychology, Adolescent - methods; Psychology, Child - methods; Psychology. Psychoanalysis. Psychiatry; Psychopathology; Psychopathology. Psychiatry; Shared environment; Siblings; Siblings - psychology; Social Environment; Twin Studies as Topic - methods; Human; externalizing; internalizing; Shared environment; Internalization; Adolescent; Environmental factor; Genetics; genetically informed studies; Review; Psychopathology; Child; genetics
• ISSN: 0021-9630; 1469-7610
• DOI: 10.1111/jcpp.12173

Background
Behavioral genetic research has historically concluded that the more important environmental influences were nonshared or result in differences between siblings, whereas environmental influences that create similarities between siblings (referred to as shared environmental influences) were indistinguishable from zero. Recent theoretical and meta‐analytic work {Burt. Psychological Bulletin [135 (2009) 608]} has challenged this conclusion as it relates to child and adolescent psychopathology, however, arguing that the shared environment is a moderate, persistent, and identifiable source of individual differences in such outcomes prior to adulthood.
Methods
The current review seeks to bolster research on the shared environment by highlighting both the logistic advantages inherent in studies of the shared environment, as well as the use of nontraditional but still genetically informed research designs to study shared environmental influences.
Results
Although often moderate in magnitude prior to adulthood and free of unsystematic measurement error, shared environmental influences are nevertheless likely to have been underestimated in prior research. Moreover, the shared environment is likely to include proximal effects of the family, as well as the effects of more distal environmental contexts such as neighborhood and school. These risk and protective factors could influence the child either as main effects or as moderators of genetic influence (i.e. gene‐environment interactions). Finally, because the absence of genetic relatedness in an otherwise nonindependent dataset also qualifies as ‘genetically informed’, studies of the shared environment are amenable to the use of novel and non‐traditional designs (with appropriate controls for selection).
Conclusions
The shared environment makes important contributions to most forms of child and adolescent psychopathology. Empirical examinations of the shared environment would thus be of real and critical value for understanding the development and persistence of common mental health issues prior to adulthood.