A religious upbringing reduces the influence of genetic factors on disinhibition: Evidence for interaction between genotype and environment on personality

Abstract

I nfor mati on on per sonal i ty, on anxi ety and depr essi on and on sever al aspects of r el i gi on w as col l ected i n 1974 Dutch fami l i es consi sti ng of adol escent and young adul t tw i ns and thei r par ents. A nal yses of these data show ed that di ffer ences betw een i ndi vi dual s i n r el i gi ous upbr i ngi ng, i n religious affiliation and in participation in church activities are not influenced by genetic factors. The familial resembl ance for di ffer ent aspects of r el i gi on i s hi gh, but can be expl ai ned enti r el y by environmental influences common to family members. Shared genes do not contribute to familial r esembl ances i n r el i gi on. The absence of geneti c i nfl uences on var i ati on i n sever al di mensi ons of religion is in contrast to findings of genetic influences on a large number of other traits that were studi ed i n these tw i n fami l i es. Di ffer ences i n r el i gi ous back gr ound ar e associ ated w i th di ffer ences in personality, especially in Sensation Seeking. Subjects with a religious upbringing, who are currently religious and who engage in church activities score lower on the scales of the Sensation Seek i ng Questi onnai r e. The most pr onounced effect i s on the Di si nhi bi ti on scal e. The r esembl ances betw een tw i ns for the Di si nhi bi ti on scal e di ffer accor di ng to thei r r el i gi ous upbr i ngi ng. Recei vi ng a r el i gi ous upbr i ngi ng seems to r educe the i nfl uence of geneti c factor s on Di si nhi bi ti on, especially in males.Keyw or ds: genotype ϫ envi ronment (G ϫ E) interaction, twins, religion, personality, sensation seeki ng I ntr oducti on A frequentl y observed fi ndi ng from behavi oural geneti cs research i s that resembl ances betw een fami l y members for a w i de range of human characteri sti cs are mai nl y due to shared genes and not to shared envi ronment. We have studi ed vari abl es rel ated to personal i ty, psychopathol ogy, l i fe styl e, cardi ovascul ar di sease, brai n functi on, cogni ti on and i ntel l i gence i n tw i ns of di fferent ages. These tw i ns, and someti mes thei r fami l y members such as parents and si bl i ngs, parti ci pate i n research projects that requi re them to come to the l aboratory for el ectrophysi ol ogi cal assessment of brai n functi on, for exampl e, or they are vi si ted at home for assessment of IQ or for 24-hour ambul ant regi strati on of heart rate and bl ood pressure. Other tw i n families parti ci pate i n l arge scal e surveys that are conducted by mailed questionnaires.In Fi gures 1 and 2 a summary i s presented, separatel y for mal es and femal es, of the mai n resul ts from these studi es i n Dutch tw i ns, w ho are regi stered w i th the Netherl ands Tw i n Regi stry. 30 The dark bars represent heritabilities, the shaded bars give esti mates for the i nfl uence of shared envi ronment and the l i ght bars show the i nfl uence of uni que envi ronmental effects (i ncl udi ng any effect of age). In these fi gures, the vari abl es have been grouped i nto four ...

The moderating effects of religiosity on the genetic and environmental determinants of smoking initiation

“…This could be similar to the effects of marriage providing social support as reported in a study that identified a diminished genetic influence on alcohol consumption in married female twins compared with their unmarried counterparts (Heath, Jardine, & Martin, 1989). Similar to studies on alcohol initiation, a religious upbringing has been shown to attenuate the heritability of behavioral disinhibition (Boomsma, de Geus, van Baal, & Koopmans, 1999). To our knowledge, no reports have investigated whether indices of religiosity influence the genetic liability for smoking initiation.…”

“…Although the studies by Koopmans, Slutske, van Baal et al (1999) and Boomsma et al (1999) found that a religious environment attenuates the heritable contributions to behavioral traits, they were limited by having to stratify their samples on the basis of twin pairs who were concordant for the presence or absence of a religious upbringing. To take full advantage of a continuum of a measure of religiosity, the present study used a method for modeling the genetic effects of a trait as a linear function of an environmental moderator (Purcell, 2002).…”

Behavioral genetics of personality

“…In another Dutch twin study, interaction between personality and environment was observed [41]. Those twins with a religious upbringing did not demonstrate as many genetic effects on the development of so-called disinhibition, characterized by sensation seeking, enjoying drinks, wild parties, and numerous sexual experiences.…”

Mapping genetic influences on human brain structure

“…interactions (23,24). These are posited to explain the paradox of high heritability but strong environmental effects on IQ (see (25,26) for a discussion of thè Flynn effect' and multiplier effects).…”