Torkild Hovde Lyngstad

• Røgeberg, Ole Jørgen; Harden, Kathryn Paige & Lyngstad, Torkild Hovde (2026). Changes in heritability and shared environmentality of educational attainment across twentieth-century Norway. Nature Communications. 17. doi: 10.1038/s41467-026-75044-2. Fulltekst i vitenarkiv Vis sammendrag

  Sociological modernization theory predicts that rising meritocracy reduces the influence of family background on education while increasing the role of individual abilities. Sibling correlations are often used as omnibus indicators of family influence, but they reflect both shared environments and shared genetics, complicating interpretation over time. This study examines changes in the genetic and environmental components of educational attainment using administrative data on more than 13,000 Norwegian twin pairs born between 1915 and 1991. We apply a Bayesian hierarchical liability-threshold model to estimate heritability and shared environmental influences across birth cohorts, accounting for changes in educational systems and population distributions. For women, the heritability of educational attainment increased steadily across the twentieth century, while shared environmental influences declined, consistent with expanding educational opportunities and gender equality. For men, neither heritability nor shared environmental influences changed significantly over time. These findings clarify how genetic and environmental contributions to education vary across historical contexts, refining interpretations of long-term trends in family influence.

• Kvalvik, Eirik Haugland; Wang, Yunpeng; Walhovd, Kristine B; Lyngstad, Torkild Hovde & Røgeberg, Ole (2026). Beyond years of schooling: Genetic associations across educational milestones in two Norwegian cohorts. PLoS Genetics. ISSN 1553-7390. 22(9). doi: 10.1371/journal.pgen.1012310. Fulltekst i vitenarkiv Vis sammendrag

  Although educational attainment is heritable, years-of-education (EduYears) measures are not designed to show how genetic associations vary across discrete educational milestones. In the Norwegian Mother, Father and Child Cohort Study (MoBa; N = 120,527) and the Norwegian Twin Registry (N = 8,910), we combined genome-wide association studies (GWAS), polygenic indices (PGIs), and twin models to characterize genetic associations with high-school completion and bachelor’s, master’s, and doctoral attainment. In transition-specific analyses conditional on prior attainment, observed-scale common-variant heritability (h 2 SNP ) and PGI discrimination followed an inverse-U pattern, peaking for progression from high-school completion to attainment of at least a bachelor’s degree (HS → BSc + ; h 2 SNP  ≈ 0.14; R 2 Tjur  ≈ 0.05) and declining at postgraduate transitions. Genetic correlations (r g ) with large-scale GWAS of EduYears (EA4) and intelligence were high at earlier transitions but lower at later ones (for EA4, r g  ≈ 0.92 at HS → BSc+ and ≈ 0.38 at MSc → PhD). In cumulative analyses of attained status in the full cohort, the point-estimate gap between twin- and SNP-based heritability narrowed from ≈ 0.38 at high-school completion to ≈ 0.11 at PhD, while genetic overlap was lower for distant than adjacent milestones (r g  ≈ 0.71 for high-school completion versus PhD and ≈ 0.92 for adjacent milestones). Sensitivity analyses using an alternative intelligence GWAS and additional PGIs showed similar transition-specific trajectories. At the doctoral transition, estimates were obtained among individuals who had attained at least a master’s degree, so attenuation there must be interpreted in light of selection and range restriction. Because EduYears converts distinct credentials and progression steps into a single numerical scale, estimates expressed per additional year should not be interpreted as though one year has the same meaning across the educational sequence. Milestone-preserving analyses make that hidden structure visible and sharpen the interpretation of education GWAS and PGIs.

• Akimova, Evelina T.; Fauske, Agnes; Jørgensen, Ruth Eva; Havdahl, Alexandra; Corfield, Elizabeth Claire & Mills, Melinda C. [Vis alle 7 forfattere av denne artikkelen] (2026). When children shape their families: Evocative effects analysis of 40,000 trios from the Norwegian Mother, Father and Child Cohort Study. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 123(30). doi: 10.1073/pnas.2532642123. Fulltekst i vitenarkiv
• Demange, Perline Aline Delle; Nivard, Michel G.; Torvik, Fartein Ask; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie & Nordmo, Magnus [Vis alle 9 forfattere av denne artikkelen] (2026). No evidence of parental mental health influencing children’s academic achievement: a within-family study. European Child and Adolescent Psychiatry. ISSN 1018-8827. doi: 10.1007/s00787-026-03100-9. Fulltekst i vitenarkiv Vis sammendrag

  Children of parents with psychopathology generally perform less well in school than their peers. Parental symptoms might not, however, account for their lower achievement, as other familial factors might contribute. To examine the role of parental symptoms, we analyse data from 9,000 families in the Norwegian Mother, Father, and Child Study (MoBa). Parents reported their symptoms of anxiety, depression, ADHD, eating disorders, and alcohol use disorder during pregnancy and during their child’s childhood. Children in 5th grade (aged 10) completed nationally-standardised tests of mathematics, reading comprehension, and English (as an additional language). Comparing children who are cousins (children-of-siblings design), we controlled for unmeasured factors shared among family members that confound the relationship between parental mental health and children’s academic achievement. We found small associations between greater parental symptoms and lower scores in reading and mathematics (− 0.060 ≤ β ≤ −0.013). However, these associations were no longer significant when comparing cousins whose parents differ in mental health. Results suggest that parental symptoms do not exert a direct, clinically meaningful effect on children’s academic achievement. Although non-significant, associations with parental symptoms measured close to the child’s academic test are less attenuated than those measured during pregnancy. Notably, comparison between the overall MoBa sample and the children-of-siblings samples suggests ascertainment differences that hinder strong generalisations. Our findings underscore the importance of quasi-experimental family designs in identifying modifiable targets in intergenerational health and education research. Supporting parental mental health is crucial but its direct effect on children’s achievement may be smaller than often thought.

• Kvalvik, Eirik Haugland; Røgeberg, Ole; Wang, Yunpeng; Lyngstad, Torkild Hovde & Walhovd, Kristine B (2025). Beyond years of schooling: Shifting genetic influences across educational milestones in two Norwegian cohorts | bioRxiv. bioRxiv. ISSN 2692-8205. doi: 10.1101/2025.10.08.680992. Fulltekst i vitenarkiv Vis sammendrag

  bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution

• Tamnes, Christian K.; Bekkhus, Mona; Eilertsen, Maja; Nes, Ragnhild Bang; Prydz, Monica Beer & Ystrom, Eivind [Vis alle 63 forfattere av denne artikkelen] (2025). The nature of the relation between mental well-being and ill-being. Nature Human Behaviour. 9(12), s. 2431–2440. doi: 10.1038/s41562-025-02319-x. Fulltekst i vitenarkiv
• Fjell, Anders Martin; Røgeberg, Ole Jørgen; Sørensen, Øystein; Amlien, Inge; Bartrés-Faz, David & Brandmaier, Andreas M. [Vis alle 23 forfattere av denne artikkelen] (2025). Reevaluating the role of education on cognitive decline and brain aging in longitudinal cohorts across 33 Western countries. Nature Medicine. ISSN 1078-8956. 31, s. 2967–2976. doi: 10.1038/s41591-025-03828-y. Fulltekst i vitenarkiv Vis sammendrag

  Why education is linked to higher cognitive function in aging is fiercely debated. Leading theories propose that education reduces brain decline in aging and enhances tolerance to brain pathology or that it does not affect cognitive decline but, rather, reflects higher early-life cognitive function. To test these theories, we analyzed 407,356 episodic memory scores from 170,795 participants older than 50 years, alongside 15,157 brain magnetic resonance imaging scans from 6,472 participants across 33 Western countries. More education was associated with better memory, larger intracranial volume and slightly larger volume of memory-sensitive brain regions. However, education did not protect against age-related decline or weakened effects of brain decline on cognition. The most parsimonious explanation for the results is that the associations reflect factors present early in life, including propensity of individuals with certain traits to pursue more education. Although education has numerous benefits, the notion that it provides protection against cognitive or brain decline is not supported. In a large cross-national study, education was linked to better memory and larger brain volumes but not to slower cognitive or brain decline with age, suggesting that the association reflects early-life factors rather than neuroprotective effects in aging.

• Jørgensen, Ruth Eva; Hootegem, Arno Van & Lyngstad, Torkild Hovde (2025). Parental Divorce and Children's Partnership Dynamics. Journal of Marriage and Family. ISSN 0022-2445. doi: 10.1111/jomf.70050. Fulltekst i vitenarkiv Vis sammendrag

  Objective This study investigates the consequences of parental divorce on offspring's likelihood of entering and dissolving marital or cohabiting partnerships, assessing whether intergenerational associations are driven by causal processes, selection factors, or both. Background Children of divorced parents tend to enter partnerships earlier, are less likely to marry, and are more likely to dissolve their partnership. While environmental explanations often presume a causal impact of parental divorce, intergenerational transmission may also arise from selection factors, such as shared traits within families. Ignoring such confounding could overestimate intergenerational associations. Method Using longitudinal Norwegian population register data, this study triangulates two research designs. First, the adoption design compares relationship outcomes of adopted children (N = 2152) to a matched sample of Norwegian-born peers (N = 2152). Second, the children-of-twins design (N = 28,535) contrasts outcomes among offspring of monozygotic and dizygotic twins, leveraging variation in divorce status between and within twin pairs. Results Parental divorce has minimal influence on offspring's partnership formation but increases their risk of partnership dissolution. Both designs reveal selectivity in who experiences dissolution. The Children-of-Twin analysis provides evidence for a causal intergenerational transmission of partnership dissolution, while results from the adoption analysis do not provide clear support for a significant causal effect. Conclusion Parental divorce affects offspring's family behavior through both environmental and genetic pathways, contributing to the intergenerational transmission of divorce. Future research should specify and test the diverse causal mechanisms linking parental divorce to family dynamics.

• Dommermuth, Lars; Lyngstad, Torkild Hovde & Wiik, Kenneth Aarskaug (2025). Fertility Intentions Across Five Decades in Norway. Comparative population studies. ISSN 1869-8980. 50, s. 129–152. doi: 10.12765/cpos-2025-09. Fulltekst i vitenarkiv Vis sammendrag

  Fertility intentions are strong predictors of future childbearing at both individual and aggregate levels, reflecting cultural norms and values around family formation and childbearing. Given the recent decline in fertility across Western industrialized societies, research on fertility intentions has become increasingly important. In particular, falling birth rates in the Nordic countries − traditionally held up as exemplars of modern family policies that balance work and parenthood − raise the question of whether women of childbearing age have experienced a shift in values related to family and childbearing. Using comparable survey data on Norwegian women aged 18 to 44 over five decades (1977, 1988, 2003, 2007, and 2020), we examine trends in fertility intentions. We consider short-term fertility intentions, defined as positive intentions to have a(nother) child within the next three to four years, as well as general fertility intentions, defined as positive intentions to have a(nother) child regardless of timing. We compare changes over the study period across demographic (age, parenthood, and partnership statuses) and socioeconomic (employment and education) groups. Our results reveal a gradual shift in short-term fertility intentions toward older age groups, reflecting changes in age-specific fertility rates and rising levels of childlessness. By 2020, both short-term and general fertility intentions had declined to their lowest levels over the study period − a trend that persisted even after controlling for key background characteristics. From 2007 to 2020, we observe a consistent decline in both types of fertility intentions across all sociodemographic groups. The decline in short-term fertility intentions began earlier among young women, childless women, women in education, and women without a co-residential partner − groups previously identified as experiencing sharper fertility declines after 2010 in the Nordic countries. The early and uniform downturn across key subgroups suggests that changing family values and life-course expectations may be driving the recent fertility decline.

• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2025). The genetic and environmental composition of socioeconomic status in Norway. Nature Communications. 16(1). doi: 10.1038/s41467-025-58961-6. Fulltekst i vitenarkiv Vis sammendrag

  Estimating the contributions of genetic and environmental factors is key to understanding differences in socioeconomic status (SES). However, the heritability of SES varies by measure, method, and context. Here, we estimate genetic and environmental sources of variance and commonality in the ‘big four’ SES indicators. We use high-quality administrative data on educational attainment, occupational prestige, income, and wealth, and employ four family-based and unrelated genotype-based heritability methods, all drawn from the same population-wide cohort of >170,000 Norwegians aged 35-45. By drawing subsamples from a consistent sample and using registry-based data, we reduce differences in estimates due to population characteristics and measurement error. Our results show that genetic variation consistently explains more for educational attainment and occupational prestige. Family-shared environmental contributions explained more for educational attainment and wealth. Our results highlight considerable common influences on the four SES indicators among genetic and shared environmental factors, but not among non-shared environmental factors. Overall, we show how the relative importance of genetic and environmental factors to SES differences in Norway varies by method and type of socioeconomic attainment. This study is a reliable source for comparing heritability methods, and for comparing SES indicators and their genetic and environmental commonality in a social-democratic welfare state.

• Cheesman, Rosa Catherine Gillespie; Anapaz, Ville; Alten, Sjoerd van; Abdellaoui, Abdel; Porneso, Ralph Pascual Ortiz & Ebeltoft, Joakim Coleman [Vis alle 16 forfattere av denne artikkelen] (2025). Genetic associations with educational fields. Nature Genetics. ISSN 1061-4036. 57, s. 2997–3006. doi: 10.1038/s41588-025-02391-z. Fulltekst i vitenarkiv Vis sammendrag

  Educational field choices shape careers, wellbeing and the societal skill distribution, yet genetic influences on what people study remain poorly understood. Here we show that genetic factors are associated with educational field specializations using genome-wide association studies (GWASs) across 463,134 individuals from Finland, Norway and the Netherlands (effective n between 40,072 and 317,209). We identified 17 independent genome-wide significant variants linked to 7 of 10 educational fields, with average heritability of 7%. The genetic signal is specific to field choice rather than educational level, persisting after controlling for years of schooling and confounding factors. By examining genetic clustering across specializations, we uncovered two key dimensions: technical versus social and practical versus abstract. We performed GWASs of these components and demonstrated distinct genetic correlations with personality, behavior and socioeconomic status. Our findings demonstrate that genomic research can illuminate ‘horizontal’ stratification, revealing insights into vocational interests and social sorting beyond traditional attainment measures.

• Grätz, Michael; Tropf, Felix C.; Torvik, Fartein Ask; Andreassen, Ole & Lyngstad, Torkild Hovde (2025). No evidence of positive causal effects of maternal and paternal age at first birth on children’s test scores at age 10 years. Nature Human Behaviour. 9, s. 731–736. doi: 10.1038/s41562-025-02108-6. Fulltekst i vitenarkiv Vis sammendrag

  Research has shown that higher maternal and paternal age is positively associated with children’s education. Debate continues as to whether these relationships are causal. This is of great interest given the postponement of first births in almost all developed countries during the twentieth century. Here we use an instrumental variable approach (Mendelian randomization) using maternal and paternal polygenic indices (PGIs) for age at first birth—while conditioning on the child’s PGI for age at first birth—to identify the causal effects of maternal and paternal age at first birth on children’s test scores based on data from the Norwegian Mother, Father and Child Cohort study. We do not find evidence of positive causal effects of both maternal and paternal age at first birth on children’s test scores at age 10 years once the children’s PGI and correlations among different PGIs are controlled for. We therefore conclude that our results do not provide evidence in favour of sociological theories that predict positive causal effects of parental age on children’s educational attainment.

• Jørgensen, Ruth Eva; Cheesman, Rosa Catherine Gillespie; Andreassen, Ole & Lyngstad, Torkild Hovde (2025). The Genetics of Partnership Dissolution. Sociological Science. 12, s. 76–96. doi: 10.15195/V12.A4. Fulltekst i vitenarkiv Vis sammendrag

  There is a genetic component to divorce risk, but little is known about which and how genetically influenced traits are involved. This study makes three major contributions to address these gaps. First, we link genetic data from the Norwegian Mother, Father, and Child Cohort Study (MoBa) to population register data and estimate the total influence of common genetic variants on partnership dissolution (N = 121, 408). Then, we identify heritable traits associated with partnership dissolution using event-history analysis and a broad set of polygenic indices. Finally, we assess whether associations are robust to controls for confounding in within-sibling models. Significant heritability estimates were found for both females (h2SNP = 0.09; SE = 0.01; p < 0.0001) and males (h2SNP = 0.03; SE = 0.01; p < 0.0001). Genetic dispositions for educational attainment and other sociodemographic factors decrease the probability of partnership dissolution, whereas dispositions for internalizing symptoms and risk behavior increase the likelihood of partnership dissolution. Integrating genetics and sociodemographic approaches can shed new light on the causes of partnership dynamics by helping us understand what drives the selection processes throughout the life course.

• Hootegem, Arno Van; Rogne, Adrian Farner; Cros, Caroline Tveter; Røgeberg, Ole Jørgen & Lyngstad, Torkild Hovde (2025). Social origins and socioeconomic outcomes: a combined twin and adoption study. European Sociological Review. ISSN 0266-7215. 41(5), s. 793–807. doi: 10.1093/esr/jcaf029. Fulltekst i vitenarkiv Vis sammendrag

  Parents and children tend to have similar socioeconomic status (SES). Sociological theory has often emphasized the role of social mechanisms in intergenerational transmission, including the influence of the broader rearing environment as well as parental investments and aid, but often not allotted an important role to genetics. Accumulating evidence suggests that genetics play an important role in the transmission of SES from parents to children. Yet, estimates differ substantially across data sets, measures and methods. Using two research designs that account for potential genetic confounding, and high-quality data from Norway, we estimate the strength of the intergenerational social transmission of a range of SES indicators. By triangulating data and designs, we obtain estimates that are more robust to idiosyncratic modelling assumptions. Measures of Norwegian parents’ socioeconomic position predict their children’s socioeconomic outcomes, but purely social mechanisms only account for a fifth of the total explained variance in intergenerational transmission.

• Hootegem, Arno Van; Rogne, Adrian Farner & Lyngstad, Torkild Hovde (2024). Heritability of class and status: Implications for sociological theory and research. Research in Social Stratification and Mobility. ISSN 0276-5624. 92. doi: 10.1016/j.rssm.2024.100940. Fulltekst i vitenarkiv Vis sammendrag

  Most individual-level outcomes of interest to sociologists are indirectly influenced by genetics, including socioeconomic outcomes like education, income, wealth, and occupational status. Despite this knowledge, an integration of sociological theories of class and status with the research literature on genetic heritability is largely lacking, and no previous studies have investigated the role of genetics specifically for class attainment – a central concept in sociology. To amend this, we estimate how much variation in such positions can be attributed to genetic and environmental factors in roughly 5000 Norwegian twin pairs. The results suggest that the variability in class and status attainment is influenced by genetics to a non-negligible degree, while shared environmental factors play a modest role as well. This is in line with previous findings using genetically informed designs to study other socioeconomic outcomes. Our study suggests that in addition to social environments, variation in class and status attainment can partly be explained by genetics.

• Jørgensen, Ruth Eva & Lyngstad, Torkild Hovde (2024). Too little within-unit variation for fixed-effects analysis? – Authors’ reply. Scandinavian Journal of Public Health. ISSN 1403-4948. doi: 10.1177/14034948241291130. Fulltekst i vitenarkiv
• Borgen, Nicolai Topstad; Zachrisson, Henrik Daae; Lyngstad, Torkild Hovde; Cheesman, Rosa Catherine Gillespie & Ystrøm, Eivind (2024). For whom neighborhoods matter: Heterogeneous effects of socioeconomic neighborhood composition on child achievement. SocArXiv. doi: 10.31235/osf.io/fst58. Fulltekst i vitenarkiv
• Baier, Tina & Lyngstad, Torkild Hovde (2024). Social Background Effects on Educational Outcomes—New Insights from Modern Genetic Science. Kölner Zeitschrift für Soziologie und Sozialpsychologie. ISSN 0023-2653. 76, s. 525–545. doi: 10.1007/s11577-024-00970-2. Fulltekst i vitenarkiv Vis sammendrag

  Sociological theory and empirical research have found that parents’ socioeconomic status and related resources affect their children’s educational outcomes. Findings from behavior genetics reveal genetic underpinnings of the intergenerational transmission of education, thus altering previous conclusions about purely environmental transmission mechanisms. In recent years, studies in molecular genetics have led to new insights. Genomic data, polygenic scores, and other facets of sociogenomics are increasingly used to advance research in social stratification. Notably, the 2018 discovery of “genetic nurture” suggested that parents’ genes influence children above and beyond the genes they directly transmitted to their children. Such indirect genetic effects can be interpreted as consequences of parental behavior, which is itself influenced by the parents’ genetics and is essential for their children’s environment. Indirect genetic effects fit hand in glove with the sociological literature because they represent environmental transmission mechanisms. For instance, parenting behaviors, which are partly influenced by parents’ genes, shape children’s home environments and possibly their later educational outcomes. However, current findings based on more sophisticated research designs demonstrate that “genetic nurture” effects are actually much smaller than initially assumed and hence call for a reevaluation of common narratives found in the social stratification literature. In this paper, we review recent developments and ongoing research integrating molecular genetics to study educational outcomes, and we discuss their implications for sociological stratification research.

• Nivard, Michel G.; Belsky, Daniel W.; Harden, K. Paige; Baier, Tina; Andreassen, Ole A. & Ystrøm, Eivind [Vis alle 8 forfattere av denne artikkelen] (2024). More than nature and nurture, indirect genetic effects on children’s academic achievement are consequences of dynastic social processes. Nature Human Behaviour. 8, s. 771–778. doi: 10.1038/s41562-023-01796-2. Fulltekst i vitenarkiv Vis sammendrag

  Families transmit genes and environments across generations. When parents’ genetics affect their children’s environments, these two modes of inheritance can produce an ‘indirect genetic effect’. Such indirect genetic effects may account for up to half of the estimated genetic variance in educational attainment. Here we tested if indirect genetic effects reflect within-nuclear-family transmission (‘genetic nurture’) or instead a multi-generational process of social stratification (‘dynastic effects’). We analysed indirect genetic effects on children’s academic achievement in their fifth to ninth years of schooling in N = 37,117 parent–offspring trios in the Norwegian Mother, Father, and Child Cohort Study (MoBa). We used pairs of genetically related families (parents were siblings, children were cousins; N = 10,913) to distinguish within-nuclear-family genetic-nurture effects from dynastic effects shared by cousins in different nuclear families. We found that indirect genetic effects on children’s academic achievement cannot be explained by processes that operate exclusively within the nuclear family.

• Hootegem, Arno Van; Røgeberg, Ole Jørgen; Bratsberg, Bernt Magne & Lyngstad, Torkild Hovde (2023). Correlation between cognitive ability and educational attainment weakens over birth cohorts. Scientific Reports. 13(1). doi: 10.1038/s41598-023-44605-6. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Educational attainment is a key indicator of status and opportunity in meritocratic societies. However, it is unclear how educational expansion has affected the link between cognitive abilities and educational attainment. As a result, this study examines the correlation between cognitive ability and educational attainment across male birth cohorts in Norway. Utilizing administrative register data covering more than four decades, we investigate multiple measures of educational attainment and their connection to cognitive abilities. Our findings reveal a consistent decline in the correlation over time. These findings question the assumed shift towards meritocracy in educational systems and highlight a more complex relationship between cognitive ability and educational attainment.

• Badini, Isabella; Ahmadzadeh, Yasmin; Wechsler, Daniel L.; Lyngstad, Torkild Hovde; Rayner, Christopher & Eilertsen, Espen Moen [Vis alle 9 forfattere av denne artikkelen] (2023). Socioeconomic status and risk for child psychopathology: exploring gene–environment interaction in the presence of gene–environment correlation using extended families in the Norwegian Mother, Father and Child Birth Cohort Study. Journal of Child Psychology and Psychiatry. ISSN 0021-9630. 65(2), s. 176–187. doi: 10.1111/jcpp.13872. Fulltekst i vitenarkiv Vis sammendrag

  Background Low socioeconomic status (SES) is associated with increased risk for emotional and behavioural problems among children. Evidence from twin studies has shown that family SES moderates genetic and environmental influences on child mental health. However, it is also known that SES is itself under genetic influence and previous gene–environment interaction (G×E) studies have not incorporated the potential genetic overlap between child mental health and family SES into G×E analyses. We applied a novel approach using extended family data to investigate the moderation of aetiological influences on child emotional and behavioural problems by parental socioeconomic status in the presence of modelled gene–environment correlation. Methods The sample comprised >28,100 children in extended-family units drawn from the Norwegian Mother, Father and Child Cohort Study (MoBa). Mothers reported children's emotional and behavioural symptoms. Parents' income and educational attainment were obtained through linkage to administrative register data. Bivariate moderation Multiple-Children-of-Twins-and-Siblings (MCoTS) models were used to analyse relationships between offspring outcomes (emotional and behavioural symptom scores) and parental socioeconomic moderators (income rank and educational attainment). Results The aetiology of child emotional symptoms was moderated by maternal and paternal educational attainment. Shared environmental influences on child emotional symptoms were greater at lower levels of parents' education. The aetiology of child behavioural symptoms was moderated by maternal, but not paternal, socioeconomic factors. Genetic factors shared between maternal income and child behavioural symptoms were greater in families with lower levels maternal income. Nonshared environmental influences on child behavioural symptoms were greater in families with higher maternal income and education. Conclusions Parental socioeconomic indicators moderated familial influences and nonshared environmental influences on child emotional and behavioural outcomes. Maternal SES and child mental health share aetiological overlap such that shared genetic influence was greater at the lower end of the socioeconomic distribution. Our findings collectively highlight the role that family socioeconomic factors play in shaping the origins of child emotional and behavioural problems.

• Jørgensen, Ruth Eva & Lyngstad, Torkild Hovde (2022). Does local income and wealth inequality affect mortality? A register-based fixed effects study of 58 million person-years. Scandinavian Journal of Public Health. ISSN 1403-4948. doi: 10.1177/14034948221126264. Fulltekst i vitenarkiv Vis sammendrag

  Aim: The Income Inequality Hypothesis asserts that income inequality causes negative health burdens within wealthy nations. We aimed to test the hypothesis in Norway, examining the relationship between both income and wealth inequality, net of individual economic resources, and individual all-cause mortality. To this day, little is known about the association between wealth inequality and mortality. In Norway, wealth is far more unequally distributed than income and can be a more prevalent indicator of long-term financial security. Methods: We estimated discrete-time event history models from Norwegian register data, covering all Norwegian-born men and women aged 25–84 years during the period 1993–2013. We include fixed effects at the municipal level, adjusting for time-invariant characteristics in the local area. Our data contain approximately 58.5 million person-year observations after sample restrictions. Results: Overall, increased income and wealth inequality (measured using Gini coefficients of individuals’ pensionable income and net worth) is not associated with higher mortality risk in Norway. With a one percentage point increase in income inequality, odds ratio (OR) for mortality was estimated at 0.998 (95% confidence interval (CI) 0.996–1.001) for men and 1.002 (95% CI 0.999–1.006) for women. Corresponding OR from increased wealth inequality was 0.998 (95% CI 0.997–1.000) for men and 0.999 (95% CI 0.998–1.001) for women. Conclusions: Our results raise further doubts about the existence of a contextual effect of economic inequality on health, at least in a Nordic setting. Extensive health policies, relatively generous benefits and high levels of trust could potentially function as a buffer against negative health consequences of increased economic inequality in Norway.

• Cheesman, Rosa Catherine Gillespie; Borgen, Nicolai T.; Lyngstad, Torkild Hovde; Eilertsen, Espen Moen; Ayorech, Ziada & Torvik, Fartein Ask [Vis alle 9 forfattere av denne artikkelen] (2022). A population-wide gene-environment interaction study on how genes, schools, and residential areas shape achievement. npj Science of learning. Fulltekst i vitenarkiv
• Cheesman, Rosa Catherine Gillespie; Borgen, Nicolai Topstad; Lyngstad, Torkild Hovde; Eilertsen, Espen Moen; Ayorech, Ziada & Torvik, Fartein Ask [Vis alle 9 forfattere av denne artikkelen] (2022). A population-wide gene-environment interaction study on how genes, schools, and residential areas shape achievement. npj Science of learning. 7, s. 1–9. doi: 10.1038/s41539-022-00145-8. Fulltekst i vitenarkiv Vis sammendrag

  Abstract A child’s environment is thought to be composed of different levels that interact with their individual genetic propensities. However, studies have not tested this theory comprehensively across multiple environmental levels. Here, we quantify the contributions of child, parent, school, neighbourhood, district, and municipality factors to achievement, and investigate interactions between polygenic indices for educational attainment (EA-PGI) and environmental levels. We link population-wide administrative data on children’s standardised test results, schools and residential identifiers to the Norwegian Mother, Father, and Child Cohort Study (MoBa), which includes &gt;23,000 genotyped parent-child trios. We test for gene-environment interactions using multilevel models with interactions between EA-PGI and random effects for school and residential environments (thus remaining agnostic to specific features of environments). We use parent EA-PGI to control for gene-environment correlation. We found an interaction between students’ EA-PGI and schools suggesting compensation: higher-performing schools can raise overall achievement without leaving children with lower EA-PGI behind. Differences between schools matter more for students with lower EA-PGI, explaining 4 versus 2% of the variance in achievement for students 2 SD below versus 2 SD above the mean EA-PGI. Neighbourhood, district, and municipality variation contribute little to achievement (&lt;2% of the variance collectively), and do not interact with children’s individual EA-PGI. Policy to reduce social inequality in achievement in Norway should focus on tackling unequal support across schools for children with difficulties.

• Isungset, Martin Arstad; Freese, Jeremy; Andreassen, Ole & Lyngstad, Torkild Hovde (2022). Birth order differences in education originate in postnatal environments. PNAS Nexus. 1(2). doi: 10.1093/pnasnexus/pgac051. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Siblings share many environments and much of their genetics. Yet, siblings turn out different. Intelligence and education are influenced by birth order, with earlier-born siblings outperforming later-borns. We investigate whether birth order differences in education are caused by biological differences present at birth, that is, genetic differences or in utero differences. Using family data that spans two generations, combining registry, survey, and genotype information, this study is based on the Norwegian Mother, Father, and Child Cohort Study (MoBa). We show that there are no genetic differences by birth order as captured by polygenic scores (PGSs) for educational attainment. Earlier-born have lower birth weight than later-born, indicating worse uterine environments. Educational outcomes are still higher for earlier-born children when we adjust for PGSs and in utero variables, indicating that birth order differences arise postnatally. Finally, we consider potential environmental influences, such as differences according to maternal age, parental educational attainment, and sibling genetic nurture. We show that birth order differences are not biological in origin, but pinning down their specific causes remains elusive.

• Isungset, Martin Arstad; Conley, Dalton C; Zachrisson, Henrik Daae; Ystrøm, Eivind; Havdahl, Alexandra & Njølstad, Pål Rasmus [Vis alle 7 forfattere av denne artikkelen] (2022). Social and genetic associations with educational performance in a Scandinavian welfare state. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 119(25). doi: 10.1073/pnas.2201869119. Fulltekst i vitenarkiv Vis sammendrag

  Recent research has suggested that across Western developed societies, the influence of genetics on educational outcomes is relatively constant. However, the degree to which family environment matters varies, such that countries with high levels of intergenerational mobility have weaker associations of family background. Research in this vein has relied on twin-based estimates, which involve variance decomposition, so direct assessment of the association of genes and environments is not possible. In the present study, we approach the question by directly measuring the impact of child genotype, parental genetic nurture, and parental realized education on educational achievement in primary and secondary school. We deploy data from a social democratic context (Norway) and contrast our findings with those derived from more liberal welfare state contexts. Results point to genetics only confounding the relationship between parent status and offspring achievement to a small degree. Genetic nurture associations are similar to those in other societies. We find no, or very small, gene–environment interactions and parent–child genotype interactions with respect to test scores. In sum, in a Scandinavian welfare state context, both genetic and environmental associations are of similar magnitude as in societies with less-robust efforts to mitigate the influence of family background.

• Baier, Tina; Eilertsen, Espen Moen; Ystrøm, Eivind; Zambrana, Imac Maria & Lyngstad, Torkild Hovde (2022). An anatomy of the intergenerational correlation of educational attainment – Learning from the educational attainments of Norwegian twins and their children. Research in Social Stratification and Mobility. ISSN 0276-5624. 79. doi: 10.1016/j.rssm.2022.100691. Fulltekst i vitenarkiv Vis sammendrag

  Research on the intergenerational correlation of educational attainment (ICE) has long attempted to identify the impact of family background, specifically parent’s education. However, previous research has largely ignored genetic inheritance. We address this shortcoming by adopting a Multiple-Children-of-Twin design and decompose the ICE into its environmental and genetic transmission mechanisms. This decomposition reveals to what extent the impact of parents’ education operates through the rearing context and/or genetic factors. We use a register-based dataset from Norway, a context with egalitarian access to education. Our results show that the direct impact of parents’ education is negligible once genetic factors are accounted for. While genetic factors represent the main driver of the ICE, the genetic variants that mattered for educational attainment in the parent generation overlap only partially with those that mattered for their offspring’s attainment. Together, our findings complement common sociological narratives on how parent’s education affects offspring’s education by emphasizing the role of genetic transmission. Furthermore, our study challenges current research practices in genetics that overlook the importance of parallel changes in social structures and gene-expression over generations.

• Baier, Tina; Lang, Volker; Grätz, Michael; Barclay, Kieron J.; Conley, Dalton C & Dawes, Christopher [Vis alle 8 forfattere av denne artikkelen] (2022). Genetic Influences on Educational Achievement in Cross-National Perspective. European Sociological Review. ISSN 0266-7215. 38(6), s. 959–974. doi: 10.1093/esr/jcac014. Fulltekst i vitenarkiv Vis sammendrag

  Abstract There is a growing interest in how social conditions moderate genetic influences on education [gene–environment interactions (GxE)]. Previous research has focused on the family, specifically parents’ social background, and has neglected the institutional environment. To assess the impact of macro-level influences, we compare genetic influences on educational achievement and their social stratification across Germany, Norway, Sweden, and the United States. We combine well-established GxE-conceptualizations with the comparative stratification literature and propose that educational systems and welfare-state regimes affect the realization of genetic potential. We analyse population-representative survey data on twins (Germany and the United States) and twin registers (Norway and Sweden), and estimate genetically sensitive variance decomposition models. Our comparative design yields three main findings. First, Germany stands out with comparatively weak genetic influences on educational achievement suggesting that early tracking limits the realization thereof. Second, in the United States genetic influences are comparatively strong and similar in size compared to the Nordic countries. Third, in Sweden genetic influences are stronger among disadvantaged families supporting the expectation that challenging and uncertain circumstances promote genetic expression. This ideosyncratic finding must be related to features of Swedish social institutions or welfare-state arrangements that are not found in otherwise similar countries.

• Evensen, Miriam; Klitkou, Søren Toksvig; Tollånes, Mette Christophersen; Øverland, Simon Nygaard; Lyngstad, Torkild Hovde & Vollset, Stein Emil [Vis alle 7 forfattere av denne artikkelen] (2021). Parental income gradients in adult health: a national cohort study. BMC Medicine. 19, s. 1–14. doi: 10.1186/s12916-021-02022-4. Fulltekst i vitenarkiv Vis sammendrag

  Background Disparities in health by adult income are well documented, but we know less about the childhood origins of health inequalities, and it remains unclear how the shape of the gradient varies across health conditions. This study examined the association between parental income in childhood and several measures of morbidity in adulthood. Methods We used administrative data on seven complete Norwegian birth cohorts born in 1967–1973 (N = 429,886) to estimate the association between parental income from birth to age 18, obtained from tax records available from 1967, linked with administrative registries on health. Health measures, observed between ages 39 and 43, were taken from registry data on consultations at primary health care services based on diagnostic codes from the International Classification of Primary Care (ICPC-2) and hospitalizations and outpatient specialist consultations registered in the National Patient Registry (ICD-10). Results Low parental income during childhood was associated with a higher risk of being diagnosed with several chronic and pain-related disorders, as well as hospitalization, but not overall primary health care use. Absolute differences were largest for disorders related to musculoskeletal pain, injuries, and depression (7–9 percentage point difference). There were also differences for chronic disorders such as hypertension (8%, CI 7.9–8.5 versus 4%, CI 4.1–4.7) and diabetes (3.2%, CI 3.0–3.4 versus 1.4%, CI 1.2–1.6). There was no difference in consultations related to respiratory disorders (20.9%, CI 20.4–21.5 versus 19.7%, CI 19.2–20.3). Childhood characteristics (parental education, low birth weight, and parental marital status) and own adult characteristics (education and income) explained a large share of the association. Conclusions Children growing up at the bottom of the parental income distribution, compared to children in the top of the income distribution, had a two- to threefold increase in somatic and psychological disorders measured in adulthood. This shows that health inequalities by socioeconomic family background persist in a Scandinavian welfare-state context with universal access to health care.

• Grätz, Michael; Barclay, Kieron J.; Wiborg, Øyvind Nicolay; Lyngstad, Torkild Hovde; Karhula, Aleksi & Erola, Jani [Vis alle 9 forfattere av denne artikkelen] (2021). Sibling similarity in education across and within societies. Demography. ISSN 0070-3370. 58(3), s. 1011–1037. doi: 10.1215/00703370-9164021. Fulltekst i vitenarkiv Vis sammendrag

  The extent to which siblings resemble each other measures the omnibus impact of family background on life chances. We study sibling similarity in cognitive skills, school grades, and educational attainment in Finland, Germany, Norway, Sweden, the United Kingdom, and the United States. We also compare sibling similarity by parental education and occupation within these societies. The comparison of sibling correlations across and within societies allows us to characterize the omnibus impact of family background on education across social landscapes. Across countries, we find larger population-level differences in sibling similarity in educational attainment than in cognitive skills and school grades. In general, sibling similarity in education varies less across countries than sibling similarity in earnings. Compared with Scandinavian countries, the United States shows more sibling similarity in cognitive skills and educational attainment but less sibling similarity in school grades. We find that socioeconomic differences in sibling similarity vary across parental resources, countries, and measures of educational success. Sweden and the United States show greater sibling similarity in educational attainment in families with a highly educated father, and Finland and Norway show greater sibling similarity in educational attainment in families with a low-educated father. We discuss the implications of our results for theories about the impact of institutions and income inequality on educational inequality and the mechanisms that underlie such inequality.

• Helland, Maren Sand; Lyngstad, Torkild Hovde; Holt, Tonje; Larsen, Linda Paarup Neigaard & Røysamb, Espen (2021). Effects of Covid-19 lockdown on parental functioning in vulnerable families. Journal of Marriage and Family. ISSN 0022-2445. 83(5), s. 1515–1526. doi: 10.1111/jomf.12789. Fulltekst i vitenarkiv Vis sammendrag

  Objective The aim of this study was to increase the knowledge about how the initial Covid-19 lockdown influenced parental functioning in vulnerable families. Background The Covid-19 pandemic has caused major changes to family life. Using a natural experiment design can potentially adjudicate on former inconclusive findings about the effects of lockdown on parental functioning in vulnerable families. Method Responses from parents in a sample of potentially vulnerable families in Norway were divided into a lockdown group if participating at baseline and during the initial Covid-19 lockdown (n = 820 responses) or into a control group if participating at baseline and before lockdown (n = 1368 responses). Mixed model regression analyses were used to mimic a wait-list design investigating direct lockdown effects on mental health, parenting stress, and three aspects of interparental conflicts, as well as moderation effects. Results The lockdown group showed significantly higher levels of parenting stress compared with the control group, but no aversive lockdown effect on mental health or destructive conflicts were found. In fact, decreased levels of verbal aggression and child involvement in conflict were found during lockdown among parents living apart. Pre-existing financial problems and conflict levels, age of youngest child, and parent gender did not moderate the lockdown effects. Conclusion The initial lockdown did not seem to adversely affect parental functioning, beyond increased parenting stress. Caution should be taken when generalizing the findings as child effects and long-term lockdown effects were not investigated.

• Barclay, Kieron J.; Lyngstad, Torkild Hovde & Conley, Dalton C (2021). The Production of Inequalities within Families and across Generations: The Intergenerational Effects of Birth Order on Educational Attainment. European Sociological Review. ISSN 0266-7215. 37(4), s. 607–625. doi: 10.1093/esr/jcab005. Fulltekst i vitenarkiv Vis sammendrag

  Abstract There has long been interest in the extent to which effects of social stratification extend and persist across generations. We take a novel approach to this question by asking whether birth order in the parental generation influences the educational attainment of their children. To address this question, we use Swedish population data on cohorts born 1960–1982. To study the effects of parental birth order, we use cousin fixed effects comparisons. In analyses where we compare cousins who share the same biological grandparents to adjust for unobserved factors in the extended family, we find that having a later-born parent reduces educational attainment to a small extent. For example, a second- or fifth-born mother reduces educational attainment by 0.09 and 0.18 years, respectively, while having a second- or fifth-born father reduces educational attainment by 0.04 and 0.11 years, respectively. After adjusting for attained parental education and social class, the parental birth order effect is practically attenuated to zero. Overall our results suggest that parental birth order influences offspring educational and socioeconomic outcomes through the parents own educational and socioeconomic attainment. We cautiously suggest that parental birth order may have potential as an instrument for parental socioeconomic status in social stratification research more generally.

• Stonawski, Marcin Jan; Rogne, Adrian Farner; Christiansen, Henning; Bang, Henrik & Lyngstad, Torkild Hovde (2021). Ethnic segregation and native out-migration in Copenhagen. European Urban and Regional Studies. ISSN 0969-7764. doi: 10.1177/09697764211039183. Fulltekst i vitenarkiv Vis sammendrag

  In this article, we study how the local concentration of ethnic minorities relates to the likelihood of out-migration by natives in Copenhagen, the capital of Denmark. In US studies, a high or increasing proportion of racial or ethnic minorities in inner-city neighborhoods is seen as an important motivation for White middle-class families’ out-migration to racially and ethnically homogeneous suburbs. The relatively egalitarian Scandinavian setting offers a contrasting case, where inner cities are less deprived and where minority groups primarily consist of immigrants and the children of immigrants who have arrived over the past few decades. We use population-wide, longitudinal administrative data covering a 12-year period, and measures of individualized neighborhoods based on exact coordinates for place of residence, to examine whether out-migration is associated with minority concentrations in the Copenhagen area. Our results largely support the presence of a native out-migration mobility pattern, in contrast to much existing literature. We also show that responses to increasing minority concentrations vary across the life course and between natives and children of immigrants.

• Walhovd, Kristine Beate; Fjell, Anders Martin; Wang, Yunpeng; Amlien, Inge; Mowinckel, Athanasia Monika & Lindenberger, Ulman [Vis alle 29 forfattere av denne artikkelen] (2021). Education and income show heterogeneous relationships to lifespan brain and cognitive differences across European and US cohorts. Cerebral Cortex. ISSN 1047-3211. 32(4), s. 839–854. doi: 10.1093/cercor/bhab248. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Higher socio-economic status (SES) has been proposed to have facilitating and protective effects on brain and cognition. We ask whether relationships between SES, brain volumes and cognitive ability differ across cohorts, by age and national origin. European and US cohorts covering the lifespan were studied (4–97 years, N = 500 000; 54 000 w/brain imaging). There was substantial heterogeneity across cohorts for all associations. Education was positively related to intracranial (ICV) and total gray matter (GM) volume. Income was related to ICV, but not GM. We did not observe reliable differences in associations as a function of age. SES was more strongly related to brain and cognition in US than European cohorts. Sample representativity varies, and this study cannot identify mechanisms underlying differences in associations across cohorts. Differences in neuroanatomical volumes partially explained SES–cognition relationships. SES was more strongly related to ICV than to GM, implying that SES–cognition relations in adulthood are less likely grounded in neuroprotective effects on GM volume in aging. The relatively stronger SES–ICV associations rather are compatible with SES–brain volume relationships being established early in life, as ICV stabilizes in childhood. The findings underscore that SES has no uniform association with, or impact on, brain and cognition.

• Lyngstad, Torkild Hovde (2020). Fra sosiobiologi til biososiologi: Kommentar til 1980-tallets debatt om sosiobiologi i TfS. Tidsskrift for samfunnsforskning (TfS). ISSN 0040-716X. 61(1), s. 46–52. doi: 10.18261/issn.1504-291X-2020-01-05. Fulltekst i vitenarkiv
• Evensen, Miriam & Lyngstad, Torkild Hovde (2020). Mental health problems in adolescence, first births, and union formation: Evidence from the Young HUNT Study. Advances in Life Course Research. ISSN 1569-4909. 43. doi: 10.1016/j.alcr.2020.100324. Fulltekst i vitenarkiv
• Helland, Maren Sand; Larsen, Linda; Lyngstad, Torkild Hovde; Gähler, Michael & Holt, Tonje (2020). Foreldrekonflikter: Mønstre innenfor og på tvers av familieform når familiesystemet utfordres. Norsk sosiologisk tidsskrift. 4(3), s. 131–150. doi: 10.18261/issn.2535-2512-2020-03-02. Fulltekst i vitenarkiv Vis sammendrag

  I denne studien la vi systemisk familieteori til grunn for å undersøke hvordan mønstre for foreldrekonflikter varierer med familieform blant foreldre som nylig har vært i kontakt med Familieverntjenesten. Formålet var å øke kunnskapen om mønstre for foreldrekonflikter i familier med særlige utfordringer. Data ble hentet fra FamilieForSK-studien. Deltakerne ble rekruttert da de møtte til samtaler eller mekling i Familieverntjenesten. Analysene er basert på svarene foreldrene ga på en rekke strukturerte spørsmål om konflikter og samhørighet dem imellom. Regresjonsanalyse ble brukt til å sammenligne mønstre for konflikter mellom foreldredyader i ulike familieformer som skiller seg fra hverandre ved om foreldrene bor sammen eller ikke, og i grad av kompleksitet på familiesystemet i form av tilstedeværelse av nye partnere eller særkullsbarn. Vi fant at mønstre for konflikter varierer med familieform blant foreldre som nylig har vært i kontakt med et familievernkontor. Blant foreldre som bodde sammen var det ingen forskjeller i konfliktmønstre mellom foreldre-dyader med eller uten særkullsbarn (kjernefamilier versus ny-kjernefamilier). Sammenlignet med foreldre som bodde fra hverandre, hadde foreldre i kjernefamilier større omfang av konflikter, men også bedre konfliktløsning og mindre destruktiv konfliktatferd. Blant foreldre som bodde fra hverandre viste resultatene bedre konfliktløsning og mindre destruktiv konfliktatferd i foreldre-dyader som inngår i mindre komplekse familiesystemer (hvor ingen av foreldrene har ny partner), sammenlignet med mer komplekse familiesystemer. Høyere grad av samhørighet mellom foreldrene hang sammen med mindre destruktiv konfliktatferd i samtlige familieformer, men sammenhengen var signifikant sterkere i foreldre-dyader i de mer komplekse familieformene (med særkullsbarn eller nye partnere). Funnene blir diskutert i relasjon til systemisk familieteori og Giddens begrep om «rene relasjoner».

• Lyngstad, Torkild Hovde; Härkönen, Juho & Rønneberg, Leiv Tore Salte (2020). Nationalistic bias in sport performance evaluations: An example from the ski jumping world cup. European Journal for Sport and Society (EJSS). ISSN 1613-8171. 17(3), s. 250–264. doi: 10.1080/16138171.2020.1792628. Fulltekst i vitenarkiv Vis sammendrag

  Illegitimate biases of non-independent judges represent a threat to the legitimacy of international sport competitions. Judges’ nationalities represent one source of bias, as they consciously or subconsciously may prefer athletes from their own nation. Such biases may affect the outcomes of competitions. The literature offers no complete consensus on the magnitude, origin and stability of such biases. In this paper, we shed light on these problems, using international ski jumping as an example. We draw on data from the FIS World Cup competitions in the 2006–2008 and 2015–2016 seasons and estimate a series of fixed-effects models to test hypotheses on nationalistic biases. Our results reaffirm suspicions of nationalistic bias in major ski jumping competitions, but also show their magnitude is too little to be of major relevance to competition outcomes. The biases vary between nations, but do not change markedly over the study period

• Rogne, Adrian Farner; Andersson, Eva K.; Malmberg, Bo & Lyngstad, Torkild Hovde (2019). Neighbourhood Concentration and Representation of Non-European migrants: New results from Norway. European Journal of Population. ISSN 0168-6577. s. 1–13. doi: 10.1007/s10680-019-09522-3. Fulltekst i vitenarkiv Vis sammendrag

  In a previous study, Andersson et al. (A comparative study of segregation patterns in Belgium, Denmark, the Netherlands and Sweden: neighbourhood concentration and representation of non-European migrants. Eur J Popul 34:1–25, 2018) compared the patterns of residential segregation between non-European immigrants and the rest of the population in four European countries, using the k-nearest neighbours approach to compute comparable measures of segregation. This approach relies on detailed geo-coded data and can be used to assess segregation levels at different neighbourhood scales. This paper updates these findings with results from Norway. Using similar data and methods, we document both similarities and striking differences between the segregation patterns in Norway and Belgium, Denmark, the Netherlands and Sweden. While the segregation patterns in Norway at larger scales are roughly comparable to those found in Denmark, but with higher concentrations of non-European immigrants in the most immigrant-dense large-scale neighbourhoods, the micro-level segregation is much lower in Norway than in the other countries. While an important finding by Andersson et al. (2018) was that segregation levels at the micro-scale of 200 nearest neighbours fell within a narrow band, with a dissimilarity index between 0.475 and 0.512 in the four countries under study, segregation levels at this scale are clearly lower in Norway, with a dissimilarity index of 0.429. We discuss possible explanations for these patterns.

• Lillehagen, Mats & Lyngstad, Torkild Hovde (2018). Immigrant Mothers` Preferences for Children’s Sex: A register-based study of fertility behavior in Norway. Population Studies. ISSN 0032-4728. 72(1), s. 91–107. doi: 10.1080/00324728.2017.1421254. Fulltekst i vitenarkiv Vis sammendrag

  Parental sex preferences have been documented in many native populations, but much less evidence is available on immigrants’ preferences for the sexes of their children. Using high-quality longitudinal register data from Norway, a country with a recent immigration history, we estimate hazards regression models of third birth risks by the sex composition of the first two children. A central question in the extant literature is whether the sex preferences of immigrant mothers match those observed in their country of origin, or if cultural adaption to local conditions is more important. Our analyses indicate that the sex preferences of immigrants generally match those previously documented for their native population, especially in the case of son preferences. The pattern of sex preferences is unmodified by the mother’s exposure to the host society. In sum, our evidence generally supports theories emphasizing cultural persistence in preferences, rather than theories of adaption or immigrant selectivity.

• Evensen, Miriam; Lyngstad, Torkild Hovde; Melkevik, Ole; Reneflot, Anne & Mykletun, Arnstein (2017). Adolescent mental health and earnings inequalities in adulthood: evidence from the Young-HUNT Study. Journal of Epidemiology and Community Health. ISSN 0143-005X. 71, s. 201–206. doi: 10.1136/jech-2015-206939. Fulltekst i vitenarkiv
• Hart, Rannveig Kaldager; Lyngstad, Torkild Hovde & Vinberg, Elina (2017). Children and Union Dissolution across Four Decades: Evidence from Norway. European Sociological Review. ISSN 0266-7215. 33(2), s. 317–331. doi: 10.1093/esr/jcx039. Fulltekst i vitenarkiv
• Syse, Astri & Lyngstad, Torkild Hovde (2017). In sickness and in health: Marital partners’ role in cancer survival. SSM - Population Health. ISSN 2352-8273. Fulltekst i vitenarkiv
• Syse, Astri & Lyngstad, Torkild Hovde (2017). In Sickness and in Health: The Role of Marital Partners in Cancer Survival. SSM - Population Health. ISSN 2352-8273. 3, s. 99–110. doi: 10.1016/j.ssmph.2016.12.007. Fulltekst i vitenarkiv Vis sammendrag

  Married cancer patients enjoy a survival advantage, potentially attributable to better health at diagnosis, earlier contact with health personnel, and/or access to resources to ensure more optimal treatment. These mechanisms only invoke the mere presence of a partner, but partners bring varying amounts of resources into the household. It is likely that also spousal resources contribute to differentials in survival net of own resources, as gradients in survival by the latter are well documented. Our aim is to examine the combined roles of own and spouses’ socioeconomic characteristics (SES) and age for cancer survival. Almost 268,000 married patients diagnosed with a first cancer after age 50 during 1975–2007 were identified from the Norwegian Cancer Registry and other national registers. In a sequence of hazard models, differences in survival by patients' own education, income and age and the role of spouses' characteristics were assessed. Furthermore, we also assessed the importance of homogamy/heterogamy along the same dimensions. Partners’ characteristics clearly matter for survival. The relative survival of patients with highly educated partners, net of their own education, is significantly higher than that of patients with lesser-educated partners. Somewhat similar effects are observed for income, net of education. A less consistent pattern is observed for age, although non-normative heterogamy patterns in age and income appear to be associated with a survival disadvantage. The naïve perspective of only considering the presence of partners may thus conceal important differences in cancer survival. Health personnel may take advantage of such knowledge in interactions with patients and their families, and gather information on resources in immediate networks that may impact prognosis favorable and/ or unfavorable and help patients utilize these resources to improve prognosis.

• Hart, Rannveig Kaldager & Lyngstad, Torkild Hovde (2016). Individualiserte livsløp? - Et sekvensanalytisk blikk på samlivene til norske menn og kvinner født 1927–1966. Tidsskrift for samfunnsforskning (TfS). ISSN 0040-716X. 2016(2), s. 135–166. doi: 10.18261/issn.1504-291x-2016-02-02. Fulltekst i vitenarkiv
• Evensen, Miriam; Lyngstad, Torkild Hovde; Melkevik, Ole & Mykletun, Arnstein (2016). The role of internalizing and externalizing problems in adolescence for adult educational attainment: evidence from sibling comparisons using data from The Young HUNT Study. European Sociological Review. ISSN 0266-7215. 32(5), s. 552–566. doi: 10.1093/esr/jcw001. Fulltekst i vitenarkiv
• Riise, Birgitte Sande; Dommermuth, Lars & Lyngstad, Torkild Hovde (2016). Intergenerational transmission of age at first birth in Norway. European Societies. ISSN 1461-6696. 18(1), s. 47–69. doi: 10.1080/14616696.2016.1141304. Fulltekst i vitenarkiv Vis sammendrag

  Using data from administrative registers, we examine the intergenerational transmission of timing of first birth in Norway for all men and women born between 1954 and 1964. We assess the extent of any intergenerational transmission using discrete-time event history analysis, and estimate associations between the age at first birth of parents and their children. Results suggest that intergenerational transmission of age at first birth is evident in all four parent–child dyads and at all ages of the first-birth process. This means that even in a society as contemporary Norway, with a welfare state that offers a range of universal social benefits, own fertility timing is correlated with parents’ fertility behavior. Furthermore, our analyses indicate that fathers’ high age at first birth is closely associated with postponed birth of sons. Results from a microsimulation suggest that the fertility timing of daughters is less malleable by changes in parental age at birth than the fertility timing of sons. Controlling for a limited set of possible confounders, we find that the intergenerational transmission of age at first birth largely persist.

• Lyngstad, Torkild Hovde & Skardhamar, Torbjørn (2015). Family formation and crime: What role for the family network? Advances in Life Course Research. ISSN 1569-4909. doi: 10.1016/j.alcr.2015.09.007. Fulltekst i vitenarkiv
• Skardhamar, Torbjørn; Savolainen, Jukka; Aase, Kjersti N. & Lyngstad, Torkild Hovde (2015). Does marriage reduce crime? Crime and justice. ISSN 0192-3234. 44, s. 385–446. doi: 10.1086/681557. Fulltekst i vitenarkiv
• Sigle-Rushton, Wendy; Lyngstad, Torkild Hovde; Andersen, Patrick Lie & Kravdal, Øystein (2014). Proceed with caution? Parents' union dissolution and children's educational achievement. Journal of Marriage and Family. ISSN 0022-2445. 76(1), s. 161–174. doi: 10.1111/jomf.12075. Fulltekst i vitenarkiv
• Skardhamar, Torbjørn; Monsbakken, Christian & Lyngstad, Torkild Hovde (2014). Crime and the transition to marriage: The role of the spouse’s criminal involvement. British Journal of Criminology. ISSN 0007-0955. 54(3), s. 411–427. doi: 10.1093/bjc/azu011. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde & Skardhamar, Torbjørn (2013). Changes in offending around the time of marriage. Journal of research in crime and delinquency. ISSN 0022-4278. 50(4), s. 608–615. doi: 10.1177/0022427812469516. Fulltekst i vitenarkiv
• Monsbakken, Christian; Lyngstad, Torkild Hovde & Skardhamar, Torbjørn (2013). Crime and the transition to parenthood: The role of sex and relationship context. British Journal of Criminology. ISSN 0007-0955. 53(1), s. 129–148. doi: 10.1093/bjc/azs052. Fulltekst i vitenarkiv
• Cooke, Lynn Prince; Erola, Jani; Evertsson, Marie; Gähler, Michael; Härkönen, Juho & Hewitt, Belinda [Vis alle 15 forfattere av denne artikkelen] (2013). Labor and love: wives' employment and divorce risk in its socio-political context. Social Politics: International Studies in Gender, State and Society. ISSN 1072-4745. 20(4), s. 482–509. doi: 10.1093/sp/jxt016. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde & Skardhamar, Torbjørn (2013). Changes in Criminal Offending around the Time of Marriage. Journal of research in crime and delinquency. ISSN 0022-4278. 50(4), s. 608–615. doi: 10.1177/0022427812469516. Fulltekst i vitenarkiv

Se alle arbeider i NVA

• Dommermuth, Lars; Lappegård, Trude; Kravdal, Øystein; Lyngstad, Torkild Hovde & Tønnessen, Marianne (2026). (+) Demografifaget trenger et hjem. Fulltekst i vitenarkiv Vis sammendrag

  Til tross for at befolkningsspørsmål er politisk brennbare, finnes det ikke noe samlet demografisk forskningsmiljø i Norge. Vi trenger minst ett nasjonalt senter for demografi.

• Kvalvik, Eirik Haugland; Røgeberg, Ole; Wang, Yunpeng & Lyngstad, Torkild Hovde (2024). Triangulating Evidence of Declining Heritability Across Educational Levels in Norway: Insights from Twin Models and Polygenic Scores. Behavior Genetics. ISSN 0001-8244. 54(6), s. 483–483. doi: 10.1007/s10519-024-10197-8. Fulltekst i vitenarkiv Vis sammendrag

  Although the genetic basis for educational attainment has been extensively studied, the progression from high school to doctoral levels remains less understood. Therefore this study employs a sequential hurdle model for analyses of twin models (N = 8910, cohorts 1965–2001) and polygenic scores (PGS, N = 114,699, cohorts 1965–1989) to explore the additive genetic effects (A) for these educational transitions across Norwegian cohorts. Findings indicate that genetic influence decreases with higher educational hurdles: for high school graduates, A = 0.6 [0.39, 0.76]; for bachelor’s degree holders, A = 0.49 [0.36, 0.64]; for master’s degree holders, A = 0.42 [0.23, 0.61]; and for doctorate holders, A = 0.3 [0.02, 0.6]. Similarly, McFadden’s pseudo R2 from PGS revealed decreasing genetic influence from high school (0.047 [0.044, 0.051]) to PhD (0.01 [0.007, 0.013]). The study also finds a selection effect, where individuals with higher PGS are more likely to surpass educational milestones, evidenced by the adjusted mean standardized PGS increasing almost linearly with educational level, from high school (- 0.29 [- 0.3, - 0.28]) to PhD (0.72 [0.67, 0.76]). This suggests that for each educational hurdle passed, the less genetic influences matter for passing the next hurdle, but that there is a selection process where individuals with higher PGS tend to more easily pass higher educational hurdles.

• Cheesman, Rosa Catherine Gillespie; Eilertsen, Espen Moen; Ayorech, Ziada Ng'ombo Laurel; Ystrøm, Eivind; Hootegem, Arno Van & Lyngstad, Torkild Hovde (2024). Parent SES and offspring mental health. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde; Berghammer, Caroline; Matysiak, Anna & Rinesi, Francesca (2024). Is single parenthood increasingly an experience of less-educated mothers? A European comparison over five decades. Demographic Research. ISSN 1435-9871. doi: 10.4054/DemRes.2024.51.34. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Triangulating Approaches to Evaluate the Genetic and Environmental Composition of Socioeconomic Status. Fulltekst i vitenarkiv
• Dommermuth, Lars; Lyngstad, Torkild Hovde & Wiik, Kenneth Aarskaug (2024). Fertility intentions across five decades in Norway. Fulltekst i vitenarkiv
• Cheesman, Rosa Catherine Gillespie; Anapaz, Ville; Alten, Sjoerd van; Abdellaoui, Abdel; Ebeltoft, Joakim Coleman & Porneso, Ralph Pascual Ortiz [Vis alle 16 forfattere av denne artikkelen] (2024). The Genetics of Educational Fields. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Parent SES and young people's mental health: Doctoral project. Fulltekst i vitenarkiv
• Hootegem, Arno Van; Rogne, Adrian Farner; Cros, Caroline Tveter; Røgeberg, Ole Jørgen & Lyngstad, Torkild Hovde (2024). Social origins and socioeconomic outcomes: A combined twin and adoption study. SocArXiv. doi: 10.31235/osf.io/y65ux. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Triangulating Approaches to Evaluate the Genetic and Environmental Composition of Socioeconomic Status: Multi-method study. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Genetic and environmental composition of SES. Fulltekst i vitenarkiv
• Ebeltoft, Joakim Coleman; Eilertsen, Espen Moen; Cheesman, Rosa Catherine Gillespie; Ayorech, Ziada; Hootegem, Arno Van & Lyngstad, Torkild Hovde [Vis alle 7 forfattere av denne artikkelen] (2024). Doctoral project: Socioeconomic status and young people's mental health. Fulltekst i vitenarkiv
• Bævre, Kåre; Holden, Lars; Lyngstad, Torkild Hovde & Modalsli, Jørgen (2023). Helsestatistikk i fare. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116. s. 30–30. Fulltekst i vitenarkiv
• Dommermuth, Lars; Lyngstad, Torkild Hovde & Wiik, Kenneth Aarskaug (2023). Fertility intentions in certain and uncertain times: The case of Norway. Fulltekst i vitenarkiv
• Hootegem, Arno Van; Rogne, Adrian Farner & Lyngstad, Torkild Hovde (2023). Heritability of Class: Implications for Theory and Research on Social Mobility. SocArXiv. doi: 10.31235/osf.io/mncet. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde & Tønnessen, Marianne (2022). Befolkningsutviklingen. I Frønes, Ivar & Kjølsrød, Lise (Red.), Det norske samfunn - bind 1. Gyldendal Norsk Forlag A/S. ISSN 9788205563414. s. 15–39. Fulltekst i vitenarkiv
• Demange, Perline; Eilertsen, Espen Moen; Nordmo, Magnus; Torvik, Fartein Ask; Lyngstad, Torkild Hovde & Nivard, Michel [Vis alle 8 forfattere av denne artikkelen] (2022). Genetic and pedigree designs to investigate the effects of parental psychopathology on children's school performance. Fulltekst i vitenarkiv
• Rogne, Adrian Farner; Hermansen, Are Skeie; Hundebo, Pål Oskar; Wessel, Terje; Lyngstad, Torkild Hovde & Birkelund, Gunn Elisabeth (2022). Finnes det “svenske tilstander” i Norge? Fulltekst i vitenarkiv
• Tønnessen, Marianne & Lyngstad, Torkild Hovde (2021). Jordas befolkning runder snart åtte milliarder – hvor mange mennesker tåler kloden vår? [Internet]. Oslo Met forskningsnyheter. Fulltekst i vitenarkiv
• Badini, Isabella; Lyngstad, Torkild Hovde; Eilertsen, Espen Moen; Ahmadzadeh, Yasmin I.; Wechsler, Daniel L & Zachrisson, Henrik Daae [Vis alle 10 forfattere av denne artikkelen] (2021). Socioeconomic status and risk for child emotional and behavioral problems: Exploring gene-environment interaction in the presence of gene-environment correlation using extended families in the Norwegian Mother, Father and Child Birth Cohort Study. Fulltekst i vitenarkiv
• Badini, Isabella; Lyngstad, Torkild Hovde; Eilertsen, Espen Moen; Ahmadzadeh, Yasmin I.; Wechsler, Daniel L & Zachrisson, Henrik Daae [Vis alle 10 forfattere av denne artikkelen] (2021). Socioeconomic status and risk for child emotional and behavioral problems: Exploring gene-environment interaction in the presence of gene-environment correlation using extended families in the Norwegian Mother, Father and Child Birth Cohort Study. Behavior Genetics. ISSN 0001-8244. 51(6), s. 691–691. Fulltekst i vitenarkiv
• Borgen, Nicolai T.; Hermansen, Are Skeie; Lyngstad, Torkild Hovde & Ystrøm, Eivind (2020). Misvisende om utdanningsulikhet. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116. Fulltekst i vitenarkiv
• Syse, Astri & Lyngstad, Torkild Hovde (2020). Ulike samfunn, ulike epidemier. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde & Lillehagen, Mats (2019). Immigrant mothers' preferences for children's sexes: A register-based study. Fulltekst i vitenarkiv
• Skardhamar, Torbjørn; Lyngstad, Torkild Hovde & Berk, Richard (2018). Prediksjon av individers fremtidige kriminalitet. Fulltekst i vitenarkiv
• Andersson, Eva K.; Lyngstad, Torkild Hovde & Sleutjes, Bart (2018). Comparing Patterns of Segregation in North-Western Europe: A Multiscalar Approach. European Journal of Population. ISSN 0168-6577. 34(2), s. 151–168. doi: 10.1007/s10680-018-9477-1. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde; Rogne, Adrian Farner; Birkelund, Gunn Elisabeth; Hermansen, Are Skeie & Skardhamar, Torbjørn (2018). Ethnic Neighborhood Segregation and Residential Mobility Dynamics: Evidence from Norwegian administrative registers 1993-2013. Fulltekst i vitenarkiv
• Holst, Cathrine & Lyngstad, Torkild Hovde (2018). Årets sosiolog 2018 - Nils Petter Gleditsch. sosiologen.no. Fulltekst i vitenarkiv
• Lillehagen, Mats & Lyngstad, Torkild Hovde (2018). De fleste norske innvandrere foretrekker sønner. Forskning.no. ISSN 1891-635X. Fulltekst i vitenarkiv
• Syse, Astri & Lyngstad, Torkild Hovde (2017). Velg partner med omhu! Fulltekst i vitenarkiv
• Syse, Astri & Lyngstad, Torkild Hovde (2017). Velg partner med omhu! Dagens næringsliv. ISSN 0803-9372. s. 27–27. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde (2016). An Anatomy of the Intergenerational Correlation in Education: Learning from Norwegian Twins and their Families. Fulltekst i vitenarkiv
• Holst, Cathrine & Lyngstad, Torkild Hovde (2016). Norsk sosiologforenings hederspris for 2016 til Trond Petersen. Sosiologisk Tidsskrift. ISSN 0804-0486. 24(2), s. 142–147. doi: 10.18261/issn.1504-2928-2016-02-05. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde (2016). Forbrytelsens matematikk. [Journal]. Intervju Dagens Næringsliv. Fulltekst i vitenarkiv
• Lillehagen, Mats & Lyngstad, Torkild Hovde (2015). Galt om genetikk og ulikhet. Morgenbladet. ISSN 0805-3847. Fulltekst i vitenarkiv
• Lillehagen, Mats & Lyngstad, Torkild Hovde (2015). Ulikhet og genetikk. Morgenbladet. ISSN 0805-3847. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde (2015). Morgenbladetsalongen: Likestillingsparadokset. [Internet]. Morgenbladet. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde (2014). Drøfting ingen botsgang. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116. Fulltekst i vitenarkiv
• Lyngstad, Torkild Hovde (2014). Eplekjekk forskningskritikk. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116. Fulltekst i vitenarkiv
• Lillehagen, Mats & Lyngstad, Torkild Hovde (2014). Parental Sex Preferences for Children among Immigrants. Fulltekst i vitenarkiv
• Lehti, Hannu; Stienstra, Kim; Lyngstad, Torkild Hovde & Baier, Tina (2025). The Role of Gender in Gene by Family SES Interactions – A Twin Study Across Four European Countries. Open Science Foundation. doi: 10.31235/osf.io/dhtms_v1. Fulltekst i vitenarkiv Vis sammendrag

  Studies on gene-by-family SES interaction (GxSES) in educational outcomes have produced mixed results. This study builds on a sociocontextual perspective, emphasizing that genetic influences are shaped by broader social forces besides family, including gender and institutional context. For example, some of the previous sociogenetic studies indicate that particularly early school tracking suppresses the genetic influences. We analyzed gene-by-environment interactions (GxE) by parental education and children's gender using large twin registers from Finland, Norway, Germany, and the Netherlands employing non-parametric gene-environment interaction models. Our results indicated that genetic influences in Germany were weaker and shared environmental effects stronger than in other countries. We did not find significant gender differences in genetic or environmental effects on educational attainment in the studied countries. Analyses of GxSES revealed that the interactions depend on gender and country context. For example, in some countries, we observed negative interaction among women, with the genetic effect being weaker among children from high-SES families. Among men, the results indicate that GxSES can have either a positive or a negative direction. We conclude that the institutional context and gender can shape gene-environment interactions related to educational attainment. Keywords: genes, environment, gender, education, family SES, educational tracking

• Røgeberg, Ole; Harden, K. Paige & Lyngstad, Torkild Hovde (2024). Social change, modernization and the heritability of educational attainment. Open Science Foundation. doi: 10.31235/osf.io/v9ymk. Fulltekst i vitenarkiv Vis sammendrag

  According to sociological modernization theory, the shift towards a more meritocratic society should reduce the impact of family background on education and increase the importance of individual abilities. Sibling correlations have been used as an omnibus indicator of the importance of families for socioeconomic outcomes. However, sibling similarities in education are influenced by both the siblings’ genetics and their shared environments, making it challenging to interpret changes over time. This study examines the changing contributions of genetic and environmental factors to educational attainment among Norwegian twins born from 1915 to 1991. Using administrative data on education for more than 13,000 twin pairs, we applied a Bayesian hierarchical liability threshold model to estimate the heritability and shared environmental influences on educational attainment across birth cohorts, while accounting for changes in the educational system and population distributions. For women, the heritability of educational attainment increased throughout the 20th century, whereas the influence of shared environmental factors decreased. This pattern corresponds with sociocultural changes that promoted gender equality and expanded educational opportunities for women. In contrast, men exhibited no significant changes in heritability or shared environmental influences over time. This study adds to the body of research on how genetic influences on educational outcomes do – and do not – differ across historical time and social context.

• Isungset, Martin Arstad; Baier, Tina & Lyngstad, Torkild Hovde (2021). Gender, Genes, and Income: How Equality of Opportunity Changed in Norway Across the 20th Century. Open Science Foundation. doi: 10.31235/osf.io/e5wjk. Fulltekst i vitenarkiv Vis sammendrag

  The income gender gap shrank dramatically in western democracies over the twentieth century. We ask whether genetic influences on lifetime income, i.e. the heritability, is the same for men and women across birth cohorts. We interpret heritability as achievement and shared environ-ments as social ascription on the basis of gender. We use data on 11,677 twin pairs born in Norway between 1915 and 1991 linked with full-population administrative income data covering the years 1967-2016. The heritability of lifetime income doubled across birth cohorts as women faced fewer social barriers to earn income. The increase in heritability and decrease in gendered shared environments indicate more equality of opportunity between gender for later-born cohorts. However, it also shows that in an extensive welfare state like Norway where gender equality has been a political priority since the 1950s, equality of opportunity was low until very recently. Furthermore, when we study men and women separately, the heritability is lower for women than for men, showing that genes are not pathwayed to influence lifetime income equally. Although we argue that genetically informed designs can be used to evaluate equality of opportunity between genders, we discuss the many interpretive challenges that remain.

• Lillehagen, Mats; Birkelund, Gunn Elisabeth & Lyngstad, Torkild Hovde (2019). Entering the mainstream? Cultural and socioeconomic dimensions of immigrant assimilation. Universitetet i Oslo. Fulltekst i vitenarkiv
• Urstad, Sivert Skålvoll; Repstad, Pål Steinar & Lyngstad, Torkild Hovde (2018). Ikke-religiøse i Norge. Sosiologiske analyser av individer uten religion. Universitetet i Agder. ISSN 9788271178888. Fulltekst i vitenarkiv

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