@article {259, title = {Differences in exam performance between pupils attending selective and non-selective schools mirror the genetic differences between them}, volume = {3}, year = {2018}, month = {2018/03/23}, pages = {3}, abstract = {

On average, students attending selective schools outperform their non-selective counterparts in national exams. These differences are often attributed to value added by the school, as well as factors schools use to select pupils, including ability, achievement and, in cases where schools charge tuition fees or are located in affluent areas, socioeconomic status. However, the possible role of DNA differences between students of different schools types has not yet been considered. We used a UK-representative sample of 4814 genotyped students to investigate exam performance at age 16 and genetic differences between students in three school types: state-funded, non-selective schools (\‘non-selective\’), state-funded, selective schools (\‘grammar\’) and private schools, which are selective (\‘private\’). We created a genome-wide polygenic score (GPS) derived from a genome-wide association study of years of education (EduYears). We found substantial mean genetic differences between students of different school types: students in non-selective schools had lower EduYears GPS compared to those in grammar (d\ =\ 0.41) and private schools (d\ =\ 0.37). Three times as many students in the top EduYears GPS decile went to a selective school compared to the bottom decile. These results were mirrored in the exam differences between school types. However, once we controlled for factors involved in pupil selection, there were no significant genetic differences between school types, and the variance in exam scores at age 16 explained by school type dropped from 7\% to \<1\%. These results show that genetic and exam differences between school types are primarily due to the heritable characteristics involved in pupil admission.

}, isbn = {2056-7936}, url = {https://doi.org/10.1038/s41539-018-0019-8}, author = {Emily Smith-Woolley and Pingault, Jean-Baptiste and Saskia Selzam and Kaili Rimfeld and Eva Krapohl and Sophie von Stumm and Asbury, Kathryn and Philip S. Dale and Young, Toby and Allen, Rebecca and Yulia Kovas and Robert Plomin} } @article {271, title = {Evidence for gene-environment correlation in child feeding: Links between common genetic variation for BMI in children and parental feeding practices}, journal = {PLOS Genetics}, volume = {14}, year = {2018}, month = {11}, pages = {1-19}, abstract = {

The parental feeding practices (PFPs) of excessive restriction of food intake (\‘restriction\’) and pressure to increase food consumption (\‘pressure\’) have been argued to causally influence child weight in opposite directions (high restriction causing overweight; high pressure causing underweight). However child weight could also \‘elicit\’ PFPs. A novel approach is to investigate gene-environment correlation between child genetic influences on BMI and PFPs. Genome-wide polygenic scores (GPS) combining BMI-associated variants were created for 10,346 children (including 3,320 DZ twin pairs) from the Twins Early Development Study using results from an independent genome-wide association study meta-analysis. Parental \‘restriction\’ and \‘pressure\’ were assessed using the Child Feeding Questionnaire. Child BMI standard deviation scores (BMI-SDS) were calculated from children\’s height and weight at age 10. Linear regression and fixed family effect models were used to test between- (n = 4,445 individuals) and within-family (n = 2,164 DZ pairs) associations between the GPS and PFPs. In addition, we performed multivariate twin analyses (n = 4,375 twin pairs) to estimate the heritabilities of PFPs and the genetic correlations between BMI-SDS and PFPs. The GPS was correlated with BMI-SDS (β = 0.20, p = 2.41x10-38). Consistent with the gene-environment correlation hypothesis, child BMI GPS was positively associated with \‘restriction\’ (β = 0.05, p = 4.19x10-4), and negatively associated with \‘pressure\’ (β = -0.08, p = 2.70x10-7). These results remained consistent after controlling for parental BMI, and after controlling for overall family contributions (within-family analyses). Heritabilities for \‘restriction\’ (43\% [40\–47\%]) and \‘pressure\’ (54\% [50\–59\%]) were moderate-to-high. Twin-based genetic correlations were moderate and positive between BMI-SDS and \‘restriction\’ (rA = 0.28 [0.23\–0.32]), and substantial and negative between BMI-SDS and \‘pressure\’ (rA = -0.48 [-0.52 - -0.44]. Results suggest that the degree to which parents limit or encourage children\’s food intake is partly influenced by children\’s genetic predispositions to higher or lower BMI. These findings point to an evocative gene-environment correlation in which heritable characteristics in the child elicit parental feeding behaviour.

}, doi = {10.1371/journal.pgen.1007757}, url = {https://doi.org/10.1371/journal.pgen.1007757}, author = {Saskia Selzam and McAdams, Tom A. and Jonathan R I Coleman and Carnell, Susan and Paul F O{\textquoteright}Reilly and Robert Plomin and Llewellyn, Clare H.} } @article {275, title = {A polygenic p factor for major psychiatric disorders}, journal = {Translational psychiatry}, volume = {8}, year = {2018}, month = {2018/10/02}, pages = {205205 - 205}, abstract = {

It has recently been proposed that a single dimension, called the p factor, can capture a person\&$\#$39;s liability to mental disorder. Relevant to the p hypothesis, recent genetic research has found surprisingly high genetic correlations between pairs of psychiatric disorders. Here, for the first time, we compare genetic correlations from different methods and examine their support for a genetic p factor. We tested the hypothesis of a genetic p factor by applying principal component analysis to matrices of genetic correlations between major psychiatric disorders estimated by three methods-family study, genome-wide complex trait analysis, and linkage-disequilibrium score regression-and on a matrix of polygenic score correlations constructed for each individual in a UK-representative sample of 7 026 unrelated individuals. All disorders loaded positively on a first unrotated principal component, which accounted for 57, 43, 35, and 22\% of the variance respectively for the four methods. Our results showed that all four methods provided strong support for a genetic p factor that represents the pinnacle of the hierarchical genetic architecture of psychopathology.

}, isbn = {2158-3188}, url = {https://www.ncbi.nlm.nih.gov/pubmed/30279410}, author = {Saskia Selzam and Jonathan R I Coleman and Caspi, Avshalom and Moffitt, Terrie E and Robert Plomin} } @article {200, title = {Genome-Wide Polygenic Scores Predict Reading Performance Throughout the School Years}, journal = {Scientific Studies of Reading}, volume = {21}, year = {2017}, month = {2017/07/04}, pages = {334 - 349}, abstract = {

It is now possible to create individual-specific genetic scores, called genome-wide polygenic scores (GPS). We used a GPS for years of education (EduYears) to predict reading performance assessed at UK National Curriculum Key Stages 1 (age 7), 2 (age 12) and 3 (age 14) and on reading tests administered at ages 7 and 12 in a UK sample of 5,825 unrelated individuals. EduYears GPS accounts for up to 5\% of the variance in reading performance at age 14. GPS predictions remained significant after accounting for general cognitive ability and family socioeconomic status. Reading performance of children in the lowest and highest 12.5\% of the EduYears GPS distribution differed by a mean growth in reading ability of approximately two school years. It seems certain that polygenic scores will be used to predict strengths and weaknesses in education.

}, isbn = {1088-84381532-799X}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5490720/}, author = {Saskia Selzam and Philip S. Dale and Wagner, Richard K and John C DeFries and Cederl{\"o}f, Martin and Paul F O{\textquoteright}Reilly and Eva Krapohl and Robert Plomin} } @article {199, title = {Predicting educational achievement from DNA}, journal = {Mol Psychiatry}, volume = {22}, year = {2017}, month = {2017/02//print}, pages = {267 - 272}, abstract = {

A genome-wide polygenic score (GPS), derived from a 2013 genome-wide association study (N=127,000), explained 2\% of the variance in total years of education (EduYears). In a follow-up study (N=329,000), a new EduYears GPS explains up to 4\%. Here, we tested the association between this latest EduYears GPS and educational achievement scores at ages 7, 12 and 16 in an independent sample of 5825 UK individuals. We found that EduYears GPS explained greater amounts of variance in educational achievement over time, up to 9\% at age 16, accounting for 15\% of the heritable variance. This is the strongest GPS prediction to date for quantitative behavioral traits. Individuals in the highest and lowest GPS septiles differed by a whole school grade at age 16. Furthermore, EduYears GPS was associated with general cognitive ability (~3.5\%) and family socioeconomic status (~7\%). There was no evidence of an interaction between EduYears GPS and family socioeconomic status on educational achievement or on general cognitive ability. These results are a harbinger of future widespread use of GPS to predict genetic risk and resilience in the social and behavioral sciences.

}, isbn = {1359-4184}, url = {http://dx.doi.org/10.1038/mp.2016.107}, author = {Saskia Selzam and Eva Krapohl and Sophie von Stumm and Paul F O{\textquoteright}Reilly and Kaili Rimfeld and Yulia Kovas and Philip S. Dale and Lee,J J and Robert Plomin} } @article {196, title = {Publication Trends Over 55 Years of Behavioral Genetic Research}, journal = {Behavior Genetics}, volume = {46}, year = {2016}, month = {Sep}, pages = {603{\textendash}607}, abstract = {

We document the growth in published papers on behavioral genetics for 5-year intervals from 1960 through 2014. We used 1861 papers published in Behavior Genetics to train our search strategy which, when applied to Ovid PsychINFO, selected more than 45,000 publications. Five trends stand out: (1) the number of behavioral genetic publications has grown enormously; nearly 20,000 papers were published in 2010\–2014. (2) The number of human quantitative genetic (QG) publications (e.g., twin and adoption studies) has steadily increased with more than 3000 papers published in 2010\–2014. (3) The number of human molecular genetic (MG) publications increased substantially from about 2000 in 2000\–2004 to 5000 in 2005\–2009 to 9000 in 2010\–2014. (4) Nonhuman publications yielded similar trends. (5) Although there has been exponential growth in MG publications, both human and nonhuman QG publications continue to grow. A searchable resource of this corpus of behavioral genetic papers is freely available online at http://www.teds.ac.uk/public{\_}datasets.html and will be updated annually.

}, issn = {1573-3297}, doi = {10.1007/s10519-016-9786-2}, url = {https://doi.org/10.1007/s10519-016-9786-2}, author = {Ayorech, Ziada and Saskia Selzam and Emily Smith-Woolley and Knopik, Valerie S. and Neiderhiser, Jenae M. and John C DeFries and Robert Plomin} } @article {195, title = {Rotation is visualisation, 3D is 2D: using a novel measure to investigate the genetics of spatial ability}, journal = {Scientific Reports}, volume = {6}, year = {2016}, month = {2016}, pages = {30545}, abstract = {

Spatial abilities\–defined broadly as the capacity to manipulate mental representations of objects and the relations between them\–have been studied widely, but with little agreement reached concerning their nature or structure. Two major putative spatial abilities are \“mental rotation\” (rotating mental models) and \“visualisation\” (complex manipulations, such as identifying objects from incomplete information), but inconsistent findings have been presented regarding their relationship to one another. Similarly inconsistent findings have been reported for the relationship between two- and three-dimensional stimuli. Behavioural genetic methods offer a largely untapped means to investigate such relationships. 1,265 twin pairs from the Twins Early Development Study completed the novel \“Bricks\” test battery, designed to tap these abilities in isolation. The results suggest substantial genetic influence unique to spatial ability as a whole, but indicate that dissociations between the more specific constructs (rotation and visualisation, in 2D and 3D) disappear when tested under identical conditions: they are highly correlated phenotypically, perfectly correlated genetically (indicating that the same genetic influences underpin performance), and are related similarly to other abilities. This has important implications for the structure of spatial ability, suggesting that the proliferation of apparent sub-domains may sometimes reflect idiosyncratic tasks rather than meaningful dissociations.

}, isbn = {2045-2322}, url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4967849/}, author = {Shakeshaft, Nicholas G and Kaili Rimfeld and Schofield, Kerry L and Saskia Selzam and Malanchini, Margherita and Rodic, Maja and Yulia Kovas and Robert Plomin} }