Discussion Using a large representative sample of the UK population, we found that personality factors explain around 6% of the variance in academic achievement at the end of compulsory education at age 16. However, at this stage of education Grit adds only 0.5% to the prediction of GCSE variance after accounting for the association between achievement and Big-5 personality factors. We believe that these results should warrant concern with the educational policy directives in the USA and UK (Shechtman, DeBarger, Dornsife, Rosier, & Yarnall, 2013). Twin analyses, conducted for the first time in the present study, showed that Grit (Perseverance of Effort and Consistency of Interest), just as other personality factors (Turkheimer, Pettersson, & Horn, 2013) are moderately heritable, with genetic factors explaining about a third of the variance. Shared environmental factors, which are factors that contribute to similarities between members of a twin pair growing up in the same family and attending the same schools, explained no significant variance in these scales. The majority of the variance in all personality factors was explained by environmental factors, which are the factors that do not contribute to similarities between twin pairs growing up in the same family and attending the same schools. It should be emphasized, however, that behavioral genetic results such as these describe components of variance in a particular population at a particular time. Specifically, heritability does not imply immutability. The most limiting finding, for any possible intervention, is that shared environmental influence is negligible. This means that current differences between families and schools explain little variance in the
Discussion Using a large representative sample of the UK population, we found that personality factors explain around 6% of the variance in academic achievement at the end of compulsory education at age 16. However, at this stage of education Grit adds only 0.5% to the prediction of GCSE variance after accounting for the association between achievement and Big-5 personality factors. We believe that these results should warrant concern with the educational policy directives in the USA and UK (Shechtman, DeBarger, Dornsife, Rosier, & Yarnall, 2013). Twin analyses, conducted for the first time in the present study, showed that Grit (Perseverance of Effort and Consistency of Interest), just as other personality factors (Turkheimer, Pettersson, & Horn, 2013) are moderately heritable, with genetic factors explaining about a third of the variance. Shared environmental factors, which are factors that contribute to similarities between members of a twin pair growing up in the same family and attending the same schools, explained no significant variance in these scales. The majority of the variance in all personality factors was explained by environmental factors, which are the factors that do not contribute to similarities between twin pairs growing up in the same family and attending the same schools. It should be emphasized, however, that behavioral genetic results such as these describe components of variance in a particular population at a particular time. Specifically, heritability does not imply immutability. The most limiting finding, for any possible intervention, is that shared environmental influence is negligible. This means that current differences between families and schools explain little variance in the
True%20Grit%20and%20Genetics_revision_clean_091115.docx