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van de Weijer MP, Pelt DHM, de Vries LP, Huider F, van der Zee MD, Helmer Q, Ligthart L, Willemsen G, Boomsma DI, de Geus E, Bartels M. Genetic and environmental influences on quality of life: The COVID-19 pandemic as a natural experiment. GENES, BRAIN, AND BEHAVIOR 2022; 21:e12796. [PMID: 35289084 PMCID: PMC9111595 DOI: 10.1111/gbb.12796] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/20/2021] [Accepted: 01/04/2022] [Indexed: 11/30/2022]
Abstract
By treating the coronavirus disease 2019 (COVID-19) pandemic as a natural experiment, we examine the influence of substantial environmental change (i.e., lockdown measures) on individual differences in quality of life (QoL) in the Netherlands. We compare QoL scores before the pandemic (N = 25,772) to QoL scores during the pandemic (N = 17,222) in a sample of twins and their family members. On a 10-point scale, we find a significant decrease in mean QoL from 7.73 (SD = 1.06) before the pandemic to 7.02 (SD = 1.36) during the pandemic (Cohen's d = 0.49). Additionally, variance decomposition shows an increase in unique environmental variance during the pandemic (0.30-1.08), and a decrease in the heritability estimate from 30.9% to 15.5%. We hypothesize that the increased environmental variance is the result of lockdown measures not impacting everybody equally. Whether these effects persist over longer periods and how they impact health inequalities remain topics for future investigation.
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Affiliation(s)
- Margot P van de Weijer
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Dirk H M Pelt
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Lianne P de Vries
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Floris Huider
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Matthijs D van der Zee
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Quinta Helmer
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Lannie Ligthart
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Gonneke Willemsen
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Dorret I Boomsma
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Eco de Geus
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
| | - Meike Bartels
- Department of Biological Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Amsterdam Public Health Research Institute, Amsterdam University Medical Centres, Amsterdam, The Netherlands
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2
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Conducting Clinical Trials in Twin Populations: A Review of Design, Analysis, Recruitment and Ethical Issues for Twin-Only Trials. Twin Res Hum Genet 2022; 24:359-364. [PMID: 35074024 DOI: 10.1017/thg.2021.52] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Although twins often participate in medical research, few clinical trials are conducted entirely in twin populations. The purpose of this review is to demonstrate the substantial benefits and address the key challenges of conducting clinical trials in twin populations, or 'twin-only trials'. We consider the unique design, analysis, recruitment and ethical issues that arise in such trials. In particular, we describe the different approaches available for randomizing twin pairs, highlight the similarity or correlation that exists between outcomes of twins, and discuss the impact of this correlation on sample size calculations and statistical analysis methods for estimating treatment effects. We also consider the role of both monozygotic and dizygotic twins for studying variation in outcomes, the factors that may affect recruitment of twins, and the ethics of conducting trials entirely in twin populations. The advantages and disadvantages of conducting twin-only trials are also discussed. Finally, we recommend that twin-only trials should be considered more often.
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3
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Heritability of overlapping impulsivity and compulsivity dimensional phenotypes. Sci Rep 2020; 10:14378. [PMID: 32873811 PMCID: PMC7463011 DOI: 10.1038/s41598-020-71013-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 08/06/2020] [Indexed: 12/22/2022] Open
Abstract
Impulsivity and compulsivity are traits relevant to a range of mental health problems and have traditionally been conceptualised as distinct constructs. Here, we reconceptualised impulsivity and compulsivity as partially overlapping phenotypes using a bifactor modelling approach and estimated heritability for their shared and unique phenotypic variance within a classical twin design. Adult twin pairs (N = 173) completed self-report questionnaires measuring psychological processes related to impulsivity and compulsivity. We fitted variance components models to three uncorrelated phenotypic dimensions: a general impulsive-compulsive dimension; and two narrower phenotypes related to impulsivity and obsessiveness.There was evidence of moderate heritability for impulsivity (A2 = 0.33), modest additive genetic or common environmental effects for obsessiveness (A2 = 0.25; C2 = 0.23), and moderate effects of common environment (C2 = 0.36) for the general dimension, This general impulsive-compulsive phenotype may reflect a quantitative liability to related mental health disorders that indexes exposure to potentially modifiable environmental risk factors.
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4
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Erbeli F, van Bergen E, Hart SA. Unraveling the Relation Between Reading Comprehension and Print Exposure. Child Dev 2019; 91:1548-1562. [PMID: 31732976 DOI: 10.1111/cdev.13339] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The purpose of this study was to test the directionality of influence between reading comprehension (RC) and print exposure (PE), thereby estimating genetic and environmental effects of this relation. The sample consisted of 910 twins in fourth through ninth grades (Mage = 12.33 years, SD = 1.41) from the Florida Twin Project on Reading, Behavior, and Environment. Using direction-of-causation model in a twin design, results supported a direction of influence running from RC to PE. This relation was underpinned by genetic and environmental factors of RC as well as PE. Implications for reading education are discussed.
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5
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Jayaweera K, Craig JM, Zavos HMS, Abeysinghe N, De Alwis S, Andras A, Dissanayake L, Dziedzic K, Fernando B, Glozier N, Hewamalage A, Ives J, Jordan KP, Kodituwakku G, Mallen C, Rahman O, Zafar S, Saxena A, Rijsdijk F, Saffery R, Simonoff E, Yusuf R, Sumathipala A. Protocol for establishing a child and adolescent twin register for mental health research and capacity building in Sri Lanka and other low and middle-income countries in South Asia. BMJ Open 2019; 9:e029332. [PMID: 31619420 PMCID: PMC6797400 DOI: 10.1136/bmjopen-2019-029332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
INTRODUCTION Worldwide, 10%-20% of children and adolescents experience mental health conditions. However, most such disorders remain undiagnosed until adolescence or adulthood. Little is known about the factors that influence mental health in children and adolescents, especially in low and middle-income countries (LMIC), where environmental threats, such as poverty and war, may affect optimal neurodevelopment. Cohort studies provide important information on risks and resilience across the life course by enabling tracking of the effects of early life environment on health during childhood and beyond. Large birth cohort studies, including twin cohorts that can be aetiologically informative, have been conducted within high-income countries but are not generalisable to LMIC. There are limited longitudinal birth cohort studies in LMIC. METHODS We sought to enhance the volume of impactful research in Sri Lanka by establishing a Centre of Excellence for cohort studies. The aim is to establish a register of infant, child and adolescent twins, including mothers pregnant with twins, starting in the districts of Colombo (Western Province) and Vavuniya (Northern Province). We will gain consent from twins or parents for future research projects. This register will provide the platform to investigate the aetiology of mental illness and the impact of challenges to early brain development on future mental health. Using this register, we will be able to conduct research that will (1) expand existing research capacity on child and adolescent mental health and twin methods; (2) further consolidate existing partnerships and (3) establish new collaborations. The initiative is underpinned by three pillars: high-quality research, ethics, and patient and public involvement and engagement (PPIE). ETHICS AND DISSEMINATION Ethical approval for this study was obtained from the Ethics Review Committee of Sri Lanka Medical Association and Keele University's Ethical Review Panel. In addition to journal publications, a range of PPIE activities have been conducted.
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Affiliation(s)
- Kaushalya Jayaweera
- Institute for Research and Development in Health and Social Care, Colombo, Sri Lanka
| | - Jeffrey M Craig
- Centre for Molecular and Medical Research, School of Medicine, Faculty of Health, Deakin University, Geelong, Victoria, Australia
| | - Helena M S Zavos
- Department of Psychology, Institute of Psychiatry, Psychology & Neuroscience, Kings College London, London, United Kingdom
| | - Nihal Abeysinghe
- Institute for Research and Development in Health and Social Care, Colombo, Sri Lanka
| | - Sunil De Alwis
- Ministry of Health, Nutrition and Indigenous Medicine, Colombo, Sri Lanka
| | - Alina Andras
- Research Institute of Primary Care and Health Sciences, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
| | - Lasith Dissanayake
- Institute for Research and Development in Health and Social Care, Colombo, Sri Lanka
| | - Krysia Dziedzic
- Arthritis Research Campaign National Primary Care Centre, Stoke on Trent, UK
| | - Buddhika Fernando
- Institute for Research and Development in Health and Social Care, Colombo, Sri Lanka
- Research Institute of Primary Care and Health Sciences, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
| | - Nick Glozier
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Asiri Hewamalage
- Ministry of Health, Nutrition and Indigenous Medicine, Colombo, Sri Lanka
| | - Jonathan Ives
- Department of Population Health Sciences, Centre for Ethics in Medicine, University of Bristol, Bristol, UK
| | - Kelvin P Jordan
- Primary Care and Health Sciences, Keele University, Keele, UK
| | - Godwin Kodituwakku
- Institute for Research and Development in Health and Social Care, Colombo, Sri Lanka
| | - Christian Mallen
- Arthritis Research UK Primary Care Centre, Keele University, Keele, UK
| | - Omar Rahman
- Public Health, Independent University, Dhaka, Bangladesh
| | - Shamsa Zafar
- Centre of Excellence in MNCH, Health Services Academy, Islamabad, Pakistan
| | - Alka Saxena
- Genomic Research Platform and Single Cell Laboratory, Biomedical Research Centre, Guy's and Saint Thomas' Hospitals NHS Trust, London, UK
| | - Fruhling Rijsdijk
- Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Richard Saffery
- Cancer and Disease Epigenetics, Murdoch Childrens Research Institute, Parkville, Victoria, Australia
- Paediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Emily Simonoff
- Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Rita Yusuf
- School of Life Sciences, Independent University, Dhaka, Bangladesh
| | - Athula Sumathipala
- Institute for Research and Development in Health and Social Care, Colombo, Sri Lanka
- Research Institute of Primary Care and Health Sciences, Keele University, Newcastle-under-Lyme, Staffordshire, United Kingdom
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6
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Abstract
Twin registries have developed as a valuable resource for the study of many aspects of disease and society over the years in many different countries. A number of these registries include large numbers of twins with data collected at varying information levels for twin cohorts over the past several decades. More recent expansion of twin datasets has allowed for the collection of genetic data, together with many other levels of 'omic' information along with multiple demographic, physiological, health outcomes and other measures typically used in epidemiologic research. Other twin data sources outside these registries reflect research interests in particular aspects of disease or specific phenotypic assessment. Twin registries have the potential to play a key role in many aspects of the artificial intelligence/machine learning-driven projects of the future and will continue to keep adapting to the changing research landscape.
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7
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Friedman NP, du Pont A, Corley RP, Hewitt JK. Longitudinal Relations Between Depressive Symptoms and Executive Functions From Adolescence to Early Adulthood: A Twin Study. Clin Psychol Sci 2018; 6:543-560. [PMID: 30250762 PMCID: PMC6150459 DOI: 10.1177/2167702618766360] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Depression is associated with deficits in executive functions (EFs)-cognitive control abilities that regulate goal-directed thoughts and actions-but the etiology of these associations is unclear. We examined the relations between depressive symptoms and multiple EF latent variables in a population-based sample of 439 twin pairs assessed at mean ages 12, 17, and 23 years. Greater depressive symptoms negatively related to a Common EF factor capturing shared variance across response inhibition, working memory updating, and mental set shifting tasks, and also negatively related to an Updating-Specific factor, but not a Shifting-Specific factor. Cross-lagged panel models suggested that the Common EF correlations reflected within-wave associations rather than prospective effects, whereas the Updating-Specific correlations reflected associations of earlier depression levels with later Updating-Specific ability. Twin models were consistent with a model in which Common EF and Updating-Specific abilities relate to depression through correlated genetic risk, with no significant environmental correlations.
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Affiliation(s)
- Naomi P Friedman
- Institute for Behavioral Genetics, University of Colorado Boulder
- Department of Psychology and Neuroscience, University of Colorado Boulder
| | - Alta du Pont
- Department of Psychology and Neuroscience, University of Colorado Boulder
| | - Robin P Corley
- Institute for Behavioral Genetics, University of Colorado Boulder
| | - John K Hewitt
- Institute for Behavioral Genetics, University of Colorado Boulder
- Department of Psychology and Neuroscience, University of Colorado Boulder
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8
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Calais-Ferreira L, Oliveira VC, Craig JM, Flander LB, Hopper JL, Teixeira-Salmela LF, Ferreira PH. Twin studies for the prognosis, prevention and treatment of musculoskeletal conditions. Braz J Phys Ther 2018; 22:184-189. [PMID: 29361503 PMCID: PMC5993967 DOI: 10.1016/j.bjpt.2017.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 12/08/2017] [Accepted: 12/14/2017] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Musculoskeletal conditions are highly prevalent in our ageing society and are therefore incurring substantial increases in population levels of years lived with disability (YLD). An evidence-based approach to the prognosis, prevention, and treatment of those disorders can allow an overall improvement in the quality of life of patients, while also softening the burden on national health care systems. METHODS In this Masterclass article, we provide an overview of the most relevant twin study designs, their advantages, limitations and major contributions to the investigation of traits related to the domain of musculoskeletal physical therapy. CONCLUSIONS Twin studies can be an important scientific tool to address issues related to musculoskeletal conditions. They allow researchers to understand how genes and environment combine to influence human health and disease. Twin registries and international collaboration through existing networks can provide resources for achieving large sample sizes and access to expertise in study design and analysis of twin data.
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Affiliation(s)
- Lucas Calais-Ferreira
- The University of Melbourne, Melbourne School of Population and Global Health, Centre for Epidemiology and Biostatistics, Melbourne, Victoria, Australia.
| | - Vinicius C Oliveira
- Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Programa de Pós-Graduação em Reabilitação e Desempenho Funcional, Diamantina, MG, Brazil
| | - Jeffrey M Craig
- Deakin University, School of Medicine, Centre for Molecular and Medical Research, Geelong, Victoria, Australia; Royal Children's Hospital, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia; The University of Melbourne, Department of Paediatrics, Melbourne, Victoria, Australia
| | - Louisa B Flander
- The University of Melbourne, Melbourne School of Population and Global Health, Centre for Epidemiology and Biostatistics, Melbourne, Victoria, Australia
| | - John L Hopper
- The University of Melbourne, Melbourne School of Population and Global Health, Centre for Epidemiology and Biostatistics, Melbourne, Victoria, Australia
| | - Luci F Teixeira-Salmela
- Universidade Federal de Minas Gerais (UFMG), Departamento de Fisioterapia, Belo Horizonte, MG, Brazil
| | - Paulo H Ferreira
- The University of Sydney, Faculty of Health Sciences, Musculoskeletal Health Research Group, Sydney, New South Wales, Australia
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9
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Twins as Participants in Randomized Controlled Trials: A Review of Published Literature. Twin Res Hum Genet 2017; 21:51-56. [DOI: 10.1017/thg.2017.67] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Monozygotic (MZ) and dizygotic (DZ) twins participate in research that partitions variance in health, disease, and behavior into genetic and environmental components. However, there are other innovative roles for twins in medical research. One such way is involving MZ and/or DZ twins in co-twin control-designed randomized controlled trials (RCTs). To our knowledge, no reviews have been conducted that summarizes the involvement of twins in RCTs. Therefore, we conducted a systematic literature search using the U.S. Clinical Trials Database, NHS electronic databases, MEDLINE, EMBASE, and PsychINFO for RCTs on publications involving MZ and/or DZ twins as RCT participants. Out of the 186,027 clinical trials registered in the U.S. clinical trial register ClinicaTrails.gov, only six RCTs used twins as participants. From 1,598 articles identified in our search, 50 peer-reviewed English language publications met our pre-defined inclusion criteria. Sample sizes for RCTs have ranged from a total number of participants from 2 to 1,162; however, 32 (64%) studies had a sample size of 100 or less, and of those, 12 (24%) had fewer than 10. Both MZ and DZ twins have been recruited to the RCTs. In most instances (33/50) each twin from a pair were assigned to different study arms. Most of those studies included MZ twins only. Despite the methodological advantages, the use of MZ and DZ twins as participants in interventional RCTs appeared limited. The continuous development of innovative twin designs, especially RCTs, indicates that twin research can extend beyond the more widely recognized heritability estimates.
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10
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Gustavson DE, Stallings MC, Corley RP, Miyake A, Hewitt JK, Friedman NP. Executive functions and substance use: Relations in late adolescence and early adulthood. JOURNAL OF ABNORMAL PSYCHOLOGY 2017; 126:257-270. [PMID: 28045282 DOI: 10.1037/abn0000250] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Poor executive functions (EFs) have been linked to substance use and abuse across multiple substances. However, it is unclear whether these associations are stronger for some EFs over others and/or some stages of substance use over others (e.g., ever using substances vs. dependence). It is also unknown whether such patterns change from adolescence to early adulthood, a transition that is characterized by changes to both EFs and substance use behaviors. In this longitudinal study of approximately 850 twins, we examined the relations between multiple EF abilities (including a common EF factor predicting 9 EF tasks) and measures of general substance use and dependence/abuse in late adolescence (mean age 17 years) and early adulthood (mean age 23 years). At the phenotypic level, common EF in adolescence was negatively related to the number of substances ever used and to last 6-month frequency of use, but not to dependence/abuse vulnerability (i.e., the number of dependence and abuse symptoms endorsed per substance that had been repeatedly used). However, in the same participants in early adulthood, common EF was only weakly related to the number of substances used, and not related to concurrent frequency of use nor dependence/abuse vulnerability. Twin analyses revealed that these associations were primarily genetic in origin, and that the genetic correlations were relatively stable over time. These results suggest that low common EF is a genetic risk factor for increased polysubstance use in late adolescence, but that non-EF factors play a larger role in the progression to substance dependence/abuse. (PsycINFO Database Record
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Affiliation(s)
| | | | - Robin P Corley
- Institute for Behavioral Genetics, University of Colorado Boulder
| | - Akira Miyake
- Department of Psychology and Neuroscience, University of Colorado Boulder
| | - John K Hewitt
- Institute for Behavioral Genetics, University of Colorado Boulder
| | - Naomi P Friedman
- Institute for Behavioral Genetics, University of Colorado Boulder
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11
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Haworth CMA, Nelson SK, Layous K, Carter K, Jacobs Bao K, Lyubomirsky S, Plomin R. Stability and Change in Genetic and Environmental Influences on Well-Being in Response to an Intervention. PLoS One 2016; 11:e0155538. [PMID: 27227410 PMCID: PMC4881940 DOI: 10.1371/journal.pone.0155538] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 04/29/2016] [Indexed: 12/03/2022] Open
Abstract
Genetic and environmental influences on complex traits can change in response to developmental and environmental contexts. Here we explore the impact of a positive activity intervention on the genetic and environmental influences on well-being and mental health in a sample of 750 adolescent twins. Twins completed a 10-week online well-being intervention, consisting of kindness and gratitude tasks and matched control activities. The results showed significant improvements both in well-being and in internalizing symptoms in response to the intervention activities. We used multivariate twin analyses of repeated measures, tracking stability and change in genetic and environmental influences, to assess the impact of this environmental intervention on these variance components. The heritability of well-being remained high both before and after the intervention, and the same genetic effects were important at each stage, even as well-being increased. The overall magnitude of environmental influences was also stable across the intervention; however, different non-shared environmental influences emerged during the intervention. Our study highlights the value of exploring the innovations in non-shared environmental influences that could provide clues to the mechanisms behind improvements in well-being. The findings also emphasize that even traits strongly influenced by genetics, like well-being, are subject to change in response to environmental interventions.
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Affiliation(s)
- Claire M. A. Haworth
- MRC Integrative Epidemiology Unit, School of Experimental Psychology & School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - S. Katherine Nelson
- Department of Psychology, Sewanee: The University of the South, Sewanee, United States of America
| | - Kristin Layous
- Department of Psychology, University of California Riverside, Riverside, United States of America
| | - Kathryn Carter
- Social, Genetic and Developmental Psychiatry Centre, King’s College London, London, United Kingdom
| | - Katherine Jacobs Bao
- Department of Psychology, University of California Riverside, Riverside, United States of America
| | - Sonja Lyubomirsky
- Department of Psychology, University of California Riverside, Riverside, United States of America
| | - Robert Plomin
- Social, Genetic and Developmental Psychiatry Centre, King’s College London, London, United Kingdom
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12
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Reiss D. Introduction to the Special Issue: Genetics, Personalized Medicine, and Behavioral Intervention-Can This Combination Improve Patient Care? PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2015; 5:499-501. [PMID: 26162195 DOI: 10.1177/1745691610383514] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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13
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Abstract
Rather than investigating the extent to which training can improve performance under experimental conditions ('what could be'), we ask about the origins of expertise as it exists in the world ('what is'). We used the twin method to investigate the genetic and environmental origins of exceptional performance in reading, a skill that is a major focus of educational training in the early school years. Selecting reading experts as the top 5% from a sample of 10,000 12-year-olds twins assessed on a battery of reading tests, three findings stand out. First, we found that genetic factors account for more than half of the difference in performance between expert and normal readers. Second, our results suggest that reading expertise is the quantitative extreme of the same genetic and environmental factors that affect reading performance for normal readers. Third, growing up in the same family and attending the same schools account for less than a fifth of the difference between expert and normal readers. We discuss implications and interpretations ('what is inherited is DNA sequence variation'; 'the abnormal is normal'). Finally, although there is no necessary relationship between 'what is' and 'what could be', the most far-reaching issues about the acquisition of expertise lie at the interface between them ('the nature of nurture: from a passive model of imposed environments to an active model of shaped experience').
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Affiliation(s)
- Robert Plomin
- King's College London, MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, London, SE5 8AF, United Kingdom
| | - Nicholas G Shakeshaft
- King's College London, MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, London, SE5 8AF, United Kingdom
| | - Andrew McMillan
- King's College London, MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, London, SE5 8AF, United Kingdom
| | - Maciej Trzaskowski
- King's College London, MRC Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, London, SE5 8AF, United Kingdom
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14
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Abstract
Twin and family studies have shown that most traits are at least moderately heritable. But what are the implications of finding genetic influence for the design of intervention and prevention programs? For complex traits, heritability does not mean immutability, and research has shown that genetic influences can change with age, context, and in response to behavioral and drug interventions. The most significant implications for intervention will come when we move from observational genetics to investigating dynamic genetics, including genetically sensitive interventions. Future interventions should be designed to overcome genetic risk and draw upon genetic strengths by changing the environment.
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Affiliation(s)
| | - Oliver S. P. Davis
- Department of Genetics, Evolution and Environment, UCL Genetics Institute, University College LondonLondon, UK
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15
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Hart SA, Taylor J, Schatschneider C. There Is a World Outside of Experimental Designs: Using Twins to Investigate Causation. ASSESSMENT FOR EFFECTIVE INTERVENTION : OFFICIAL JOURNAL OF THE COUNCIL FOR EDUCATIONAL DIAGNOSTIC SERVICES 2013; 38:117-126. [PMID: 23525781 PMCID: PMC3604986 DOI: 10.1177/1534508412451490] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study introduces a co-twin control method commonly used in the medical literature but not often within educational research. This method allows for a comparison of twins discordant for an "exposure," approximating alternative outcomes in the counterfactual model. Example analyses use data drawn from the Florida Twin Project on Reading to determine whether exposure to "teacher quality," measured by growth in oral reading fluency (ORF) scores of classmates, causally affects ORF performance of twins in the subsequent years. The analysis highlights PROC MIXED in SAS, including a novel expansion to allow for the nested data. Results from 2,788 twins suggested that being in classrooms with lower teacher quality in first grade leads to lower ORF scores in second and third grade with little indication of possible genetic or environmental confounding.
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Affiliation(s)
- Sara A. Hart
- The Florida State University, Tallahassee, FL, USA
- The Florida Center for Reading Research, Tallahassee, FL, USA
| | | | - Christopher Schatschneider
- The Florida State University, Tallahassee, FL, USA
- The Florida Center for Reading Research, Tallahassee, FL, USA
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16
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Eaton NR, Krueger RF, South SC, Gruenewald TL, Seeman TE, Roberts BW. Genes, environments, personality, and successful aging: toward a comprehensive developmental model in later life. J Gerontol A Biol Sci Med Sci 2012; 67:480-8. [PMID: 22454369 DOI: 10.1093/gerona/gls090] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Outcomes in aging and health research, such as longevity, can be conceptualized as reflecting both genetic and environmental (nongenetic) effects. Parsing genetic and environmental influences can be challenging, particularly when taking a life span perspective, but an understanding of how genetic variants and environments relate to successful aging is critical to public health and intervention efforts. METHODS We review the literature, and survey promising methods, to understand this interplay. We also propose the investigation of personality as a nexus connecting genetics, environments, and health outcomes. RESULTS Personality traits may reflect psychological mechanisms by which underlying etiologic (genetic and environmental) effects predispose individuals to broad propensities to engage in (un)healthy patterns of behavior across the life span. In terms of methodology, traditional behavior genetic approaches have been used profitably to understand how genetic factors and environments relate to health and personality in somewhat separate literatures; we discuss how other behavior genetic approaches can help connect these literatures and provide new insights. CONCLUSIONS Co-twin control designs can be employed to help determine causality via a closer approximation of the idealized counterfactual design. Gene-by-environment interaction (G × E) designs can be employed to understand how individual difference characteristics, such as personality, might moderate genetic and environmental influences on successful aging outcomes. Application of such methods can clarify the interplay of genes, environments, personality, and successful aging.
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Affiliation(s)
- Nicholas R Eaton
- Department of Psychology, University of Minnesota, Minneapolis, MN 55455, USA.
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