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Because educational achievement at the end of compulsory schooling represents a major tipping point in life, understanding its causes and correlates is important for individual children, their families, and society. Here we identify the general ingredients of educational achievement using a multivariate design that goes beyond intelligence to consider a wide range of predictors, such as self-efficacy, personality, and behavior problems, to assess their independent and joint contributions to educational achievement. We use a genetically sensitive design to address the question of why educational achievement is so highly heritable. We focus on the results of a United Kingdom-wide examination, the General Certificate of Secondary Education (GCSE), which is administered at the end of compulsory education at age 16. GCSE scores were obtained for 13,306 twins at age 16, whom we also assessed contemporaneously on 83 scales that were condensed to nine broad psychological domains, including intelligence, self-efficacy, personality, well-being, and behavior problems. The mean of GCSE core subjects (English, mathematics, science) is more heritable (62%) than the nine predictor domains (35-58%). Each of the domains correlates significantly with GCSE results, and these correlations are largely mediated genetically. The main finding is that, although intelligence accounts for more of the heritability of GCSE than any other single domain, the other domains collectively account for about as much GCSE heritability as intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE. We conclude that the high heritability of educational achievement reflects many genetically influenced traits, not just intelligence.academic achievement | twin studies | behavioral genetics | general cognitive ability | personalized learning

These findings indicate that early individual differences and impairments in word recognition are principally influenced by genetic factors and may involve partly distinct genetic or environmental effects in boys and girls. Crucially, they also provide evidence that reading impairments are linked genetically to the normal distribution. Genetic risk for early impairments in word recognition is continuous rather than discrete.

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Introduction A number of different theoretical approaches to understanding the etiology of ejaculatory dysfunction have been proposed, but no behavior genetic study has yet, to our knowledge, been conducted to explore the genetic and environmental influences on ejaculatory dysfunction. Aim The aim of the present study was to explore the genetic and environmental effects on premature (PE) and delayed (DE) ejaculation in a population-based sample. Methods The genetic and environmental influences on PE and DE were investigated in a population-based sample of 1,196 Finnish male twins, age 33–43 years, with 91 identical and 110 complete twin pairs. Several different aspects of ejaculatory function were measured by a self-report questionnaire (e.g., latency time, subjective experience of ejaculatory control). Factor analyses distinguished two subcomponents of ejaculatory function, and subsequently, composite variables measuring PE and DE were created. Structural equation modeling was performed on the composite variables. Main Outcome Measures Measurement of genetic and environmental effects on PE and DE. Results The results suggested moderate genetic influence (28%) on PE, but not on DE (0%). There was a moderate familial effect on DE with shared environmental effects accounting for 24% of the variance. However, omission of the shared environmental component did not directly result in a significantly decreased model fit for DE, and omission of the additive genetic component did not directly result in a significantly decreased fit for the PE model. Conclusions The findings from the present study provide useful information regarding the etiology and understanding of ejaculatory dysfunction.