Claire M A Haworth

• BA, MSc, PhD
• Professor of Behavioural Genetics at University of Bristol

Educational attainment is associated with a range of positive outcomes, yet its impact on wellbeing is unclear, and complicated by high correlations with intelligence. We use genetic and observational data to investigate for the first time, whether educational attainment and intelligence are causally and independently related to wellbeing. Results...

Background: The use of social media data to predict mental health outcomes has the potential to allow for the continuous monitoring of mental health and well-being and provide timely information that can supplement traditional clinical assessments. However, it is crucial that the methodologies used to create models for this purpose are of high qua...

Motivation: Social media represent an unrivalled opportunity for epidemiological cohorts to collect large amounts of high-resolution time course data on mental health. Equally, the high-quality data held by epidemiological cohorts could greatly benefit social media research as a source of ground truth for validating digital phenotyping algorithms....

BACKGROUND The use of social media data to predict mental health outcomes has the potential to allow for the continuous monitoring of mental health and well-being and provide timely information that can supplement traditional clinical assessments. However, it is crucial that the methodologies used to create models for this purpose are of high quali...

The relationship between mental health and social media has received significant research and policy attention. However, there is little population-representative data about who social media users are which limits understanding of confounding factors between mental health and social media. Here we profile users of Facebook, Twitter, Instagram, Snap...

Background Body mass index (BMI) shows strong continuity over childhood and adolescence and high childhood BMI is the strongest predictor of adult obesity. Genetic factors strongly contribute to this continuity, but it is still poorly known how their contribution changes over childhood and adolescence. Thus, we used the genetic twin design to estim...

Background In recent decades, China has experienced dramatic changes to its social and economic environment, which has affected the distribution of wellbeing across its citizens. While several studies have investigated individual level predictors of wellbeing in the Chinese population, less research has been done looking at contextual effects. This...

Introduction: Digital footprint records - the tracks and traces amassed by individuals as a result of their interactions with the internet, digital devices and services - can provide ecologically valid data on individual behaviours. These could enhance longitudinal population study databanks; but few UK longitudinal studies are attempting this. Wh...

Background Digital phenotypes such as social media data are increasingly being used to infer supposed trends in population mental health and wellbeing. These methods are attractive for their potential scale and timeliness. However, many methodological aspects need investigation to establish if these approaches could be applied successfully. We aim...

Background: Autistic traits are influenced by both genetic and environmental factors, and are known to vary geographically in prevalence. But to what extent does their aetiology also vary from place to place? Methods: We applied a novel spatial approach to data on autistic traits from two large twin studies, the Child and Adolescent Twin Study i...

Previous studies suggest an individual’s risk of depression following adversity may be moderated by their genetic liability. No study, however, has examined peer victimisation, an experience repeatedly associated with mental illness. We explore whether the negative mental health outcomes following victimisation can be partly attributed to genetic f...

Background: Not all victims of bullying go on to develop problems with their mental health. To understand factors that may confer resilience, many have explored the moderating role of protective factors in relation to mental illness. No study to date, however, has considered moderators of adult wellbeing following victimisation. We explore 14 prot...

Abstract Background Peer victimisation is a common occurrence and has well-established links with a range of psychiatric problems in adulthood. Significantly less is known however, about how victimisation influences positive aspects of mental health such as wellbeing. The purpose of this study was therefore to assess for the first time, whether pee...

Background: Peer victimisation is a common occurrence in schools and has well-established links with a range of psychiatric problems in adulthood. Significantly less is known however, about how victimisation influences positive aspects of mental health such as wellbeing. The purpose of this study was therefore to assess for the first time, whether...

Background: Peer victimisation is a common occurrence and has well-established links with a range of psychiatric problems in adulthood. Significantly less is known however, about how victimisation influences positive aspects of mental health such as wellbeing. The purpose of this study was therefore to assess for the first time, whether peer victim...

Background: Peer victimisation is a common occurrence and has well-established links with a range of psychiatric problems in adulthood. Significantly less is known however, about how victimisation influences positive aspects of mental health such as wellbeing. The purpose of this study was therefore to assess for the first time, whether peer victim...

Background: Cohort studies gather huge volumes of information about a range of phenotypes but new sources of information such as social media data are yet to be integrated. Participant’s long-term engagement with cohort studies, as well as the potential for their social media data to be linked to other longitudinal data, may give participants a uni...

Background Autistic traits are influenced by both genetic and environmental factors, and are known to vary geographically in prevalence. But to what extent does their aetiology also vary from place to place? Methods We applied a novel spatial approach to data on autistic traits from two large twin studies, the Child and Adolescent Twin Study in Sw...

Background: Cohort studies gather huge volumes of information about a range of phenotypes but new sources of information such as social media data are yet to be integrated. Participant’s long-term engagement with cohort studies, as well as the potential for their social media data to be linked to other longitudinal data, could provide novel advance...

The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body...

Objectives: To investigate whether the association between subjective wellbeing (subjective happiness and life satisfaction) and cardiometabolic health is causal. Design: Two sample, bidirectional mendelian randomisation study. Setting: Genetic data taken from various cohorts comprised of the general population (mostly individuals of European...

Web appendix: Supplementary materials

Background: The genetic architecture of birth size may differ geographically and over time. We examined differences in the genetic and environmental contributions to birthweight, length and ponderal index (PI) across geographical-cultural regions (Europe, North America and Australia, and East Asia) and across birth cohorts, and how gestational age...

Objectives To investigate whether the association between subjective wellbeing (subjective happiness and life satisfaction) and physical health is causal. Design We conducted two-sample bidirectional Mendelian randomisation between subjective wellbeing and six measures of physical health: coronary artery disease, myocardial infarction, total chole...

Background: There is evidence that birth size is positively associated with height in later life, but it remains unclear whether this is explained by genetic factors or the intrauterine environment. Aim: To analyze the associations of birth weight, length and ponderal index with height from infancy through adulthood within mono- and dizygotic tw...

Interventions rarely have a universal effect on all individuals. Reasons ranging from participant characteristics, context and fidelity of intervention completion could cause some people to respond more positively than others. Understanding these individual differences in intervention response may provide clues to the mechanisms behind the interven...

Complete results for interaction model for wellbeing response. (DOCX)

Basic model for wellbeing response using cases with complete predictor information. (DOCX)

Basic model for mental health response using cases with complete predictor information. (DOCX)

Fit statistics for mental health outcome models. (DOCX)

Difference between drop outs and non dropouts. (DOCX)

Basic model for wellbeing response. (DOCX)

Variance inflation factors of potential predictors. (DOCX)

Exploratory t-to-enter statistics for potential level 2 predictors of wellbeing change. (DOCX)

Fit statistics for wellbeing outcome models. (DOCX)

Basic model for mental health response. (DOCX)

Exploratory t-to-enter statistics for potential level 2 predictors of mental health change. (DOCX)

Complete results for interaction model for mental health response. (DOCX)

Complete results for interaction model for wellbeing response, not including effort measures as predictors. (DOCX)

Complete results for interaction model for mental health response, not including effort measures as predictors. (DOCX)

Power curve of interaction effect of agreeableness during the intervention phase for wellbeing outcome. (DOCX)

Late adolescence is a crucial, but underexplored, developmental stage with respect to the aetiology of social support. These individuals are experiencing many major life changes and social support can help them adjust to the associated environmental stressors of this time. Using 1,215 18-year-old twin pairs from the Twins Early Development Study, w...

Some life events appear heritable due to the genetic influence on related behaviours. Shared genetic influence between negative behaviours and negative life events has previously been established. This study investigated whether subjective wellbeing and positive life events were genetically associated. Participants in the Twins Early Development St...

Individual differences in number sense correlate with mathematical ability and performance, although the presence and strength of this relationship differs across studies. Inconsistencies in the literature may stem from heterogeneity of number sense and mathematical ability constructs. Sample characteristics may also play a role as changes in the r...

Objective Advanced paternal age (APA) at conception has been linked with autism and schizophrenia in offspring, neurodevelopmental disorders that affect social functioning. The current study explored the effects of paternal age on social development in the general population. Method We used multilevel growth modelling to investigate APA effects on...

Table S1. Means (SD) and ANOVA results. Table S2. Twin intraclass correlations split by sex and zygosity (95% confidence interval). Table S3. Estimates of standardized variance components (95% confidence intervals) of genetic and environmental influence from the Cholesky decomposition. Table S4. Genetic and environmental correlations and bivaria...

Online media use has become an increasingly important behavioral domain over the past decade. However, studies into the etiology of individual differences in media use have focused primarily on pathological use. Here, for the first time, we test the genetic influences on online media use in a UK representative sample of 16 year old twins, who were...

Factor analyses on media use variables. (DOCX)

Total variance explained in media use factor analysis. (DOCX)

Factor analyses on Facebook use variables. (DOCX)

Sex limitation sub-model comparisons: Factorized educational screen time. (DOCX)

Portion of questionnaire assessing Facebook use. (DOCX)

Portion of questionnaire assessing online media use. (DOCX)

Total variance explained in Facebook factor analysis. (DOCX)

Sex limitation model fitting results with 95% confidence intervals, depicting A, C and E estimates separately for males and females. (DOCX)

Sex limitation sub-model comparisons: Factorized entertainment screen time. (DOCX)

Sex limitation sub-model comparisons: Facebook Factor. (DOCX)

Proportion of time spent on different forms of media for total sample and across gender and zygosity. (DOCX)

Sex limitation sub-model comparisons: Factorized gaming. (DOCX)

Univariate genetic results. (DOCX)

Behavioral traits generally show moderate to strong genetic influence, with heritability estimates of around 50%. Some recent research has suggested that trust may be an exception because it is more strongly influenced by social interactions. In a sample of over 7,000 adolescent twins from the United Kingdom's Twins Early Development Study, we foun...

In the version of this article initially published, one of the affiliations listed for author Maciej Trzaskowski, to the Department of Public Health, Faculty of Medicine, University of Split, Split, Croatia, was included in error. The correct affiliation for this author is the Queensland Brain Institute, University of Queensland, Brisbane, Queensla...

Background: Both genetic and environmental factors are known to affect body mass index (BMI), but detailed understanding of how their effects differ during childhood and adolescence is lacking. Objectives: We analyzed the genetic and environmental contributions to BMI variation from infancy to early adulthood and the ways they differ by sex and...

Height variation is known to be determined by both genetic and environmental factors, but a systematic description of how their influences differ by sex, age and global regions is lacking. We conducted an individual-based pooled analysis of 45 twin cohorts from 20 countries, including 180,520 paired measurements at ages 1–19 years. The proportion o...

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 interve...

Standardized Means (Standard Deviations) for Well-Being and Mental Health. (DOCX)

Phenotypic Correlations Within Well-Being and Mental Health Across Time. (DOCX)

Fit Statistics for Multilevel Models of Intervention Response. (DOCX)

Intervention instructions: The text used in the intervention for both the control activities and the positive activities. (DOCX)

The maintenance of normal body weight is disrupted in patients with anorexia nervosa (AN) for prolonged periods of time. Prior to the onset of AN, premorbid body mass index (BMI) spans the entire range from underweight to obese. After recovery, patients have reduced rates of overweight and obesity. As such, loci involved in body weight regulation m...

Very few genetic variants have been associated with depression and neuroticism, likely because of limitations on sample size in previous studies. Subjective well-being, a phenotype that is genetically correlated with both of these traits, has not yet been studied with genome-wide data. We conducted genome-wide association studies of three phenotype...

We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had...

Background Stressful life events (SLEs) are associated with psychotic experiences. SLEs might act as an environmental risk factor, but may also share a genetic propensity with psychotic experiences. Aims To estimate the extent to which genetic and environmental factors influence the relationship between SLEs and psychotic experiences. Method Self-...

Appendix S1. Subdimensions of ADHD traits. Appendix S2. ADHD traits (total score).

Psychological research has contributed to considerable progress in understanding and treating mental illness, however, we know much less about mental health and wellbeing, and how we can promote human flourishing (Seligman & Csikszentmihalyi, 2000). Studying what goes well in life, and how to improve wellbeing and foster human potential are central...

Moderate inverse correlations are typically found between well-being and mental illness. We aimed to investigate the role of genes and environments in explaining the relationships between two aspects of well-being and two measures of internalizing symptoms. Altogether, 4700 pairs of 16-year-old twins contributed data on subjective happiness and lif...

A large number of genetic loci are associated with adult body mass index. However, the genetics of childhood body mass index are largely unknown. We performed a meta-analysis of genome-wide association studies of childhood body mass index, using sex- and age-adjusted standard deviation scores. We included 35 668 children from 20 studies in the disc...

Background: Although attention deficit hyperactivity disorder (ADHD) is thought to reflect a continuously distributed quantitative trait, it is assessed through binary diagnosis or skewed measures biased towards its high, symptomatic extreme. A growing trend is to study the positive tail of normally distributed traits, a promising avenue, for exam...

A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an i...

For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m 2 ) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address thi...

Background Mindfulness-based therapies have been shown to be effective in treating depression and reducing cognitive biases. Anxiety sensitivity is one cognitive bias that may play a role in the association between mindfulness and depressive symptoms. It refers to an enhanced sensitivity toward symptoms of anxiety, with a belief that these are harm...

Peer behaviour plays an important role in the development of social adjustment, though little is known about its genetic architecture. We conducted a twin study combined with a genome-wide complex trait analysis (GCTA) and a genome-wide screen to characterise genetic influences on problematic peer behaviour during childhood and adolescence. This in...

Twin studies suggest that expressive vocabulary at textasciitilde24 months is modestly heritable. However, the genes influencing this early linguistic phenotype are unknown. Here we conduct a genome-wide screen and follow-up study of expressive vocabulary in toddlers of European descent from up to four studies of the EArly Genetics and Lifecourse E...

Importance The onset of psychosis is usually preceded by psychotic experiences (PE). Little is known about the etiology of PE and whether the degree of genetic and environmental influences varies across different levels of severity. A recognized challenge is to identify individuals at high risk of developing psychotic disorders prior to disease on...

This chapter evaluates the contribution of behavioral genetics to the understanding of mathematical development. Quantitative genetic methods are introduced first and are followed by a review of the existing literature on the relative contribution of genes and environments to variation in mathematical ability at different ages and in different popu...

Dissecting how genetic and environmental influences impact on learning is helpful for maximizing numeracy and literacy. Here we show, using twin and genome-wide analysis, that there is a substantial genetic component to children's ability in reading and mathematics, and estimate that around one half of the observed correlation in these traits is du...

Background: Peer interaction plays an important role in the development of social competence, and problematic childhood peer relationships often precede later maladjusted behaviour. Some links between early peer rejection and later maladaptive functioning however might be mediated through an underlying pathology. This includes impairments in social...

Little is known about genes regulating male puberty. Further, while many identified pubertal timing variants associate with age at menarche, a late manifestation of puberty, and body mass, little is known about these variants' relationship to pubertal initiation or tempo. To address these questions, we performed genome-wide association meta-analysi...