| 1. |
- Frazier-Wood, Alexis C., et al.
(författare)
-
Genetic variants associated with subjective well-being, depressive symptoms, and neuroticism identified through genome-wide analyses
- 2016
-
Ingår i: Nature Genetics. - : Nature Research (part of Springer Nature). - 1061-4036 .- 1546-1718. ; 48, s. 624-
-
Tidskriftsartikel (refereegranskat)abstract
- 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 phenotypes: subjective well-being (n = 298,420), depressive symptoms (n = 161,460), and neuroticism (n = 170,911). We identify 3 variants associated with subjective well-being, 2 variants associated with depressive symptoms, and 11 variants associated with neuroticism, including 2 inversion polymorphisms. The two loci associated with depressive symptoms replicate in an independent depression sample. Joint analyses that exploit the high genetic correlations between the phenotypes (vertical bar(p) over cap vertical bar approximate to 0.8) strengthen the overall credibility of the findings and allow us to identify additional variants. Across our phenotypes, loci regulating expression in central nervous system and adrenal or pancreas tissues are strongly enriched for association.
|
|
| 2. |
- Pedersen, Nancy L., et al.
(författare)
-
IGEMS : The Consortium on Interplay of Genes and Environment Across Multiple Studies - An Update
- 2019
-
Ingår i: Twin Research and Human Genetics. - : Cambridge University Press. - 1832-4274 .- 1839-2628. ; 22:6, s. 809-816
-
Tidskriftsartikel (refereegranskat)abstract
- The Interplay of Genes and Environment across Multiple Studies (IGEMS) is a consortium of 18 twin studies from 5 different countries (Sweden, Denmark, Finland, United States, and Australia) established to explore the nature of gene-environment (GE) interplay in functioning across the adult lifespan. Fifteen of the studies are longitudinal, with follow-up as long as 59 years after baseline. The combined data from over 76,000 participants aged 14-103 at intake (including over 10,000 monozygotic and over 17,000 dizygotic twin pairs) support two primary research emphases: (1) investigation of models of GE interplay of early life adversity, and social factors at micro and macro environmental levels and with diverse outcomes, including mortality, physical functioning and psychological functioning; and (2) improved understanding of risk and protective factors for dementia by incorporating unmeasured and measured genetic factors with a wide range of exposures measured in young adulthood, midlife and later life.
|
|
| 3. |
- Madison, Guy, et al.
(författare)
-
Common genetic influences on intelligence and auditory simple reaction time in a large Swedish sample
- 2016
-
Ingår i: Intelligence. - : Elsevier. - 0160-2896 .- 1873-7935. ; 59, s. 157-162
-
Tidskriftsartikel (refereegranskat)abstract
- Intelligence and cognitive ability have long been associated with chronometric performance measures, such as reaction time (RT), but few studies have investigated auditory RT in this context. The nature of this relationship is important for understanding the etiology and structure of intelligence. Here, we present a bivariate twin analysis of simple auditory RT and psychometric intelligence (measured by the Wiener Matrizen Test). The sample consisted of 1,816 complete twin pairs and 4623 singletons enrolled in the Swedish Twin Registry, who performed the tests online. The heritabilities were 0.54 and 0.21 for intelligence and RT, respectively, and the phenotypic correlation was −0.17, 47% of which was explained by common genetic variance. These results are comparable to those found for visual RT and for other cognitive tests, and add RT in the auditory modality to the small literature on common genetic influences across intelligence and other cognitive and chronometric variables.
|
|
| 4. |
- Mosing, Miriam A., et al.
(författare)
-
Did sexual selection shape human music? : Testing predictions from the sexual selection hypothesis of music evolution using a large genetically informative sample of over 10,000 twins
- 2015
-
Ingår i: Evolution and human behavior. - : Elsevier. - 1090-5138 .- 1879-0607. ; 36:5, s. 359-366
-
Tidskriftsartikel (refereegranskat)abstract
- Although music is a universal feature of human culture, little is known about its origins and functions. A prominent theory of music evolution is the sexual selection hypothesis, which proposes that music evolved as a signal of genetic quality to potential mates. The sexual selection hypothesis offers several empirically testable predictions. First, musically skilled and active individuals should have greater mating success than less-skilled individuals. Second, if musical ability functions as an indicator of genetic quality, it is expected to be associated with other traits putatively related to genetic quality. Third, associations as per the first and second predictions are expected to be at least partly due to overlapping genetic influences. We tested these predictions in a large genetically informative sample of 10,975 Swedish twin individuals aged between 27 and 54 years (M = 40.1, SD = 7.7), using musical aptitude and music achievement as measures of musical ability. To assess mating success we examined number of sex-partners, age of first intercourse, sociosexuality, and number of offspring. General intelligence, simple reaction time, and height were used to investigate relationships with traits putatively related to genetic quality. Twin modeling showed moderate genetic influences on musical aptitude for both sexes (heritability estimates were 38% for males and 51% for females). Music achievement was also moderately influenced by genetic influences in males (heritability = 57%), but the genetic influences were low and nonsignificant for females (heritability = 9%). Contrary to predictions, the majority of phenotypic associations between musical ability and music achievement with mating success were nonsignificant or significant in the other direction, with those with greater musical ability scoring lower on the measures of mating success. Genetic correlations between these measures were also nonsignificant. Most correlations of musical aptitude and music achievement with genetic quality measures were significant, including correlations with general intelligence, simple reaction time, and, in females, height (but only for aptitude). However, only the correlation between musical aptitude and general intelligence in men was significantly driven by overlapping genetic influences. Our findings provide little support for a role of sexual selection in the evolution of musical ability. Alternative explanations and limitations are discussed.
|
|
| 5. |
- Mosing, Miriam A, et al.
(författare)
-
Investigating cognitive transfer within the framework of music practice : genetic pleiotropy rather than causality
- 2016
-
Ingår i: Developmental Science. - : Wiley-Blackwell. - 1363-755X .- 1467-7687. ; 19:3, s. 504-512
-
Tidskriftsartikel (refereegranskat)abstract
- The idea of far transfer effects in the cognitive sciences has received much attention in recent years. One domain where far transfer effects have frequently been reported is music education, with the prevailing idea that music practice entails an increase in cognitive ability (IQ). While cross-sectional studies consistently find significant associations between music practice and IQ, randomized controlled trials, however, report mixed results. An alternative to the hypothesis of cognitive transfer effects is that some underlying factors, such as shared genes, influence practice behaviour and IQ causing associations on the phenotypic level. Here we explored the hypothesis of far transfer within the framework of music practice. A co-twin control design combined with classical twin-modelling based on a sample of more than 10,500 twins was used to explore causal associations between music practice and IQ as well as underlying genetic and environmental influences. As expected, phenotypic associations were moderate (r = 0.11 and r = 0.10 for males and females, respectively). However, the relationship disappeared when controlling for genetic and shared environmental influences using the co-twin control method, indicating that a highly practiced twin did not have higher IQ than the untrained co-twin. In line with that finding, the relationship between practice and IQ was mostly due to shared genetic influences. Findings strongly suggest that associations between music practice and IQ in the general population are non-causal in nature. The implications of the present findings for research on plasticity, modularity, and transfer are discussed.
|
|
| 6. |
- Mosing, Miriam A., et al.
(författare)
-
The genetic architecture of correlations between perceptual timing, motor timing, and intelligence
- 2016
-
Ingår i: Intelligence. - : Elsevier BV. - 0160-2896 .- 1873-7935. ; 57, s. 33-40
-
Tidskriftsartikel (refereegranskat)abstract
- Psychometric intelligence correlates with performance on a wide range of sensory and motor tasks that involve processing of temporal information in the millisecond-second range. For some timing tasks, e.g. reaction time and discrimination of temporal stimuli in working memory, the associations with intelligence are likely to involve top-down mechanisms such as attention. However, studies on repetitive, automatic motor timing tasks indicate that correlations between intelligence and timing also may reflect bottom-up mechanisms, i.e. basic neural properties that influence both the temporal accuracy of behavior and cognitive processes. Here, we study the genetic architecture of the associations between intelligence, perceptual timing (auditory rhythm discrimination) and motor timing (finger tapping) in a large twin cohort. Specifically, we hypothesized that the associations between these tasks on the phenotypic level involve broad pleiotropic genetic effects that influence all three tasks, as well as additional genetic effects on the covariation between perceptual and motor timing. Phenotypic associations between the variables were low to moderate, with Pearson's correlations in the range 0.17-0.32. Trivariate twin modeling showed that the associations between the three variables were essentially due to shared genetic influences. In support of the hypotheses, we found evidence for pleiotropic effects on motor timing, perceptual timing, and intelligence, as well as additional genetic covariation between the two timing tasks that was not shared with intelligence. We conclude, first, that genetic factors underlying intelligence may involve genes which influence brain properties of importance for the temporal accuracy of neural processing. We discuss possible neural substrates of such effects. Secondly, the correlation between motor and perceptual timing also partly explained by genetic influences that are unrelated to intelligence.
|
|
| 7. |
- Ullén, Fredrik, et al.
(författare)
-
Associations between motor timing, music practice, and intelligence studied in a large sample of twins
- 2015
-
Ingår i: Annals of the New York Academy of Sciences. - : Blackwell Publishing. - 0077-8923 .- 1749-6632. ; 1337, s. 125-129
-
Tidskriftsartikel (refereegranskat)abstract
- Music performance depends critically on precise processing of time. A common model behavior in studies of motor timing is isochronous serial interval production (ISIP), that is, hand/finger movements with a regular beat. ISIP accuracy is related to both music practice and intelligence. Here we present a study of these associations in a large twin cohort, demonstrating that the effects of music practice and intelligence on motor timing are additive, with no significant multiplicative (interaction) effect. Furthermore, the association between music practice and motor timing was analyzed with the use of a co-twin control design using intrapair differences. These analyses revealed that the phenotypic association disappeared when all genetic and common environmental factors were controlled. This suggests that the observed association may not reflect a causal effect of music practice on ISIP performance but rather reflect common influences (e.g., genetic effects) on both outcomes. The relevance of these findings for models of practice and expert performance is discussed.
|
|
| 8. |
- Verweij, Karin J. H., et al.
(författare)
-
Individual differences in personality masculinity-femininity : examining the effects of genes, environment, and prenatal hormone transfer
- 2016
-
Ingår i: Twin Research and Human Genetics. - : Cambridge University Press (CUP). - 1832-4274 .- 1839-2628. ; 19:2, s. 87-96
-
Tidskriftsartikel (refereegranskat)abstract
- Males and females score differently on some personality traits, but the underlying etiology of these differences is not well understood. This study examined genetic, environmental, and prenatal hormonal influences on individual differences in personality masculinity-femininity (M-F). We used Big-Five personality inventory data of 9,520 Swedish twins (aged 27 to 54) to create a bipolar M-F personality scale. Using biometrical twin modeling, we estimated the influence of genetic and environmental factors on individual differences in a M-F personality score. Furthermore, we tested whether prenatal hormone transfer may influence individuals' M-F scores by comparing the scores of twins with a same-sex versus those with an opposite-sex co-twin. On average, males scored 1.09 standard deviations higher than females on the created M-F scale. Around a third of the variation in M-F personality score was attributable to genetic factors, while family environmental factors had no influence. Males and females from opposite-sex pairs scored significantly more masculine (both approximately 0.1 SD) than those from same-sex pairs. In conclusion, genetic influences explain part of the individual differences in personality M-F, and hormone transfer from the male to the female twin during pregnancy may increase the level of masculinization in females. Additional well-powered studies are needed to clarify this association and determine the underlying mechanisms in both sexes.
|
|
