scholarly journals The Pioneering Contributions of Irving Gottesman

2017 ◽  
Vol 5 (2) ◽  
pp. 424-426
Author(s):  
Keith H. Nuechterlein
Keyword(s):  
Mental Disorders ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Twin Studies ◽  
Conceptual Base ◽  
Basic Assumptions ◽  
Research Programs ◽  
The World ◽  
Stress Models ◽  
And Behavior

Irving Gottesman was one of the leading psychopathologists and behavior geneticists of our time, greatly influencing our basic conceptualization of the transmission of schizophrenia and other major mental disorders in ways that impacted research programs around the world. Here we highlight his landmark twin studies of schizophrenia, his introduction of the concept of endophenotypes, and his role in providing the conceptual base for vulnerability/stress models of schizophrenia. His ability to influence our basic assumptions about the nature of genetic factors, environmental factors, and their interaction in the onset and course of major mental disorders was truly remarkable.

The Genetics of Political Attitudes and Behavior: Claims and Refutations

2010 ◽  
Vol 12 (3) ◽  
pp. 200-217 ◽  
Author(s):  
Jay Joseph
Keyword(s):  
Genetic Factors ◽  
Political Attitudes ◽  
Molecular Level ◽  
Twin Studies ◽  
Theoretical Assumption ◽  
Study Results ◽  
Twin Method ◽  
And Behavior ◽  
Attitudes And Behavior ◽  
Equal Environments

Some political scientists have argued in recent years that twin research shows that genetic factors play an important role in shaping political attitudes, ideologies, and behavior. Moreover, some researchers claim to have identified genes for political traits at the molecular level. The author argues that the main theoretical assumption of the twin method, which holds that monozygotic and dizygotic twin pairs experience equal environments, is untenable. Therefore, the results of twin studies can be completely explained by nongenetic factors. The author also argues that recent gene discovery claims in political science are unlikely to be replicated. He concludes that because genetic interpretations of twin study results are confounded by environmental factors, political scientists have no reason to revise previous socialization theories of political traits.

scholarly journals Twin Studies in Auto-immune Disease

1994 ◽  
Vol 43 (1-2) ◽  
pp. 71-81 ◽  
Author(s):  
R.D.G. Leslie ◽  
M. Hawa
Keyword(s):  
Environmental Factors ◽  
Lupus Erythematosus ◽  
Genetic Factors ◽  
Disease Risk ◽  
Twin Studies ◽  
Identical Twins ◽  
Test Bed ◽  
Immune Mediated ◽  
Organ Specific ◽  
Insulin Dependent

AbstractImmune-mediated diseases affect up to 5% of the population and are a major cause of morbidity and mortality. These diseases can be organ specific, such as insulin-dependent diabetes (IDDM) and non-organ specific, such as Rheumatoid Arthritis (RA). Identical and non-identical twins have been used to establish whether these diseases are determined by genetic or environmental factors. The results of these studies have been collated in a new section of the Mendel Institute in Rome.Diseases included in these studies included IDDM, RA, Systemic Lupus Erythematosus (SLE), Multiple Sclerosis (MS) and Myasthenia. Striking differences in concordance rates between identical and non-identical twins in all these studies suggest that genetic factors are important in causing these diseases. All the diseases are known to be associated with HLA genes on chromosome 6 which may account for some or all of the genetic susceptibility. However, in the majority of pairs the affected twin has an unaffected co-twin. These observations suggest that non-genetically determined factors, probably environmental factors and not somatic mutations, are critical. The study of unaffected co-twins, who are at high disease-risk, has allowed the identification of changes which precede and predict the clinical disease. The immune-mediated destruction in many of these diseases is probably caused by T-lymphocytes. Twin studies have shown the importance of genetic factors in determining T-cell responses. Identical twins should, therefore, provide the perfect test bed to assess the role of T-cells in immune-mediated diseases.

Trauma Exposure and Stress Response: Exploration of Mechanisms of Cause and Effect

2007 ◽  
Vol 10 (4) ◽  
pp. 564-572 ◽  
Author(s):  
Kerry L. Jang ◽  
Steven Taylor ◽  
Murray B. Stein ◽  
Shinji Yamagata
Keyword(s):  
Stress Response ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Traumatic Events ◽  
Environmental Influences ◽  
Twin Studies ◽  
Posttraumatic Stress Symptoms ◽  
Dizygotic Twin ◽  
Stress Symptoms ◽  
Assaultive Trauma

AbstractPeople differ markedly in their risk for developing posttraumatic stress symptoms (PTSS) after exposure to traumatic events. Twin studies suggest that the trauma-PTSS relationship is moderated by genetic and environmental influences. The present study tested for specific types of genetic and environmental interaction effects on PTSS. A sample of 222 monozygotic and 184 dizygotic twin pairs reported on lifetime frequency of assaultive and nonassaultive trauma and associated PTSS. Biometric analyses indicated that in the case of nonassaultive trauma, PTSS were directly affected by environmental factors that also influence exposure to nonassaultive trauma. For assaultive trauma both genetic and non-shared environmental influences jointly affected PTSS, and the number of traumatic events moderated the severity of PTSS. Genetic factors were found to become less important beyond some threshold (e.g., 3 or 4 types of serious trauma) suggesting that genetic factors — which may confer either risk or resilience to PTSS — modify these symptoms within a range of human experience, beyond which environmental effects supervene.

A Behavioral-Genetic Study of Alexithymia and its Relationships with Trait Emotional Intelligence

2011 ◽  
Vol 14 (6) ◽  
pp. 539-543 ◽  
Author(s):  
Holly M. Baughman ◽  
Sara Schwartz ◽  
Julie Aitken Schermer ◽  
Livia Veselka ◽  
K. V. Petrides ◽  
...  
Keyword(s):  
Emotional Intelligence ◽  
Individual Differences ◽  
Environmental Factors ◽  
Genetic Factors ◽  
Twin Studies ◽  
Trait Emotional Intelligence ◽  
Behavioral Genetic ◽  
Genetic And Environmental Factors ◽  
Trait Emotional Intelligence Questionnaire ◽  
Behavioral Genetic Study

The present study is the first to examine relationships between alexithymia and trait emotional intelligence (trait EI or trait emotional self-efficacy) at the phenotypic, genetic, and environmental levels. The study was also conducted to resolve inconsistencies in previous twin studies that have provided estimates of the extent to which genetic and environmental factors contribute to individual differences in alexithymia. Participants were 216 monozygotic and 45 dizygotic same-sex twin pairs who completed the Toronto Alexithymia Scale-20. In a pilot study, a sub-sample of 118 MZ and 27 DZ pairs also completed the Trait Emotional Intelligence Questionnaire. Results demonstrated that a combination of genetic and non-shared environmental influences contribute to individual differences in alexithymia. As expected, alexithymia and trait EI were negatively correlated at the phenotypic level. Bivariate behavioral genetic analyses showed that that all but one of these correlations was primarily attributable to correlated genetic factors and secondarily to correlated non-shared environmental factors.

Bibliography on Prenatal and Natal Influences in Twins

1978 ◽  
Vol 27 ◽  
pp. 97-113 ◽  
Author(s):  
Bronson Price
Keyword(s):  
Environmental Factors ◽  
Twin Studies ◽  
Complete Information ◽  
Prenatal Development ◽  
Single Source ◽  
Review Of The Literature ◽  
Adult Age ◽  
And Behavior

AbstractThe author agrees with earlier writers that most of the differences observed in monozygotic pairs are due to unusual or extreme environmental factors acting before or during the twins' birth. Although they are typical of development in twins, these environmental factors can hardly be considered typical of development in other individuals. This point, as a review of the literature shows, is often overlooked by those who study twins in the childhood or adult age ranges. As a result the inferences drawn from twin differences are frequently mistaken, or at least quite exaggerated so far as the significance of postnatal influences in non-twins is concerned. At the same tihe, if allowance is made for the environmental biases peculiar to twin studies, the findings may be said to establish more about the importance of heredity in the medical and behavior sciences than most investigators have thought. In the author's opinion the largest single source of bias is the mutual circulation that exists during prenatal development of the majority of monozygotic pairs. Data on that circulation's difference-producing effects are reviewed and related to studies of mature twins. Effects of lateral inversions (asymmetry reversals) and of “natal” factors (chiefly conditions of delivery) are also reviewed, and methods of judging the importance of all three of the biasing conditions are outlined. Need for obtaining systematic and complete information about the natal factors is stressed.

scholarly journals Genetic origin of the relationship between parental negativity and behavior problems from early childhood to adolescence: A longitudinal genetically sensitive study

2013 ◽  
Vol 25 (2) ◽  
pp. 487-500 ◽  
Author(s):  
Silvia Alemany ◽  
Frühling V. Rijsdijk ◽  
Claire Margaret Alison Haworth ◽  
Lourdes Fañanás ◽  
Robert Plomin
Keyword(s):  
Early Childhood ◽  
Environmental Factors ◽  
Behavior Problems ◽  
Genetic Factors ◽  
Causal Pathways ◽  
Longitudinal Association ◽  
Genetic And Environmental Factors ◽  
And Behavior ◽  
The Relationship

AbstractLittle is known about how genetic and environmental factors contribute to the association between parental negativity and behavior problems from early childhood to adolescence. The current study fitted a cross-lagged model in a sample consisting of 4,075 twin pairs to explore (a) the role of genetic and environmental factors in the relationship between parental negativity and behavior problems from age 4 to age 12, (b) whether parent-driven and child-driven processes independently explain the association, and (c) whether there are sex differences in this relationship. Both phenotypes showed substantial genetic influence at both ages. The concurrent overlap between them was mainly accounted for by genetic factors. Causal pathways representing stability of the phenotypes and parent-driven and child-driven effects significantly and independently account for the association. Significant but slight differences were found between males and females for parent-driven effects. These results were highly similar when general cognitive ability was added as a covariate. In summary, the longitudinal association between parental negativity and behavior problems seems to be bidirectional and mainly accounted for by genetic factors. Furthermore, child-driven effects were mainly genetically mediated, and parent-driven effects were a function of both genetic and shared-environmental factors.

scholarly journals The Epidemiology and Etiology of Keratoconus

2012 ◽  
Vol 1 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Ariela Gordon-Shaag ◽  
Michel Millodot ◽  
Einat Shneor
Keyword(s):  
Environmental Factors ◽  
Genetic Predisposition ◽  
Genetic Factors ◽  
Family Studies ◽  
Twin Studies ◽  
Uv Exposure ◽  
Genetic Loci ◽  
Multiple Genes ◽  
Inferior Portion ◽  
Epidemiological Information

ABSTRACT Keratoconus is a noninflammatory disorder characterized by ectasia of the central or inferior portion of the cornea. This review presents the scant epidemiological information known to date and the factors believed to cause the development of the disease. They are the genetic factors for which evidence come from family studies, twin studies and genetic loci. There appears to be multiple genes causing a keratoconus phenotype with variable penetration. However, the genetic predisposition might not be enough; environmental factors, such as eye rubbing, atopy and UV exposure, may have a role in generating the disease. How to cite this article Gordon-Shaag A, Millodot M, Shneor E. The Epidemiology and Etiology of Keratoconus. Int J Keratoco Ectatic Corneal Dis 2012;1(1):7-15.

scholarly journals Advantages of linking national registries with twin registries for epidemiological research

2016 ◽  
Vol 26 (1-2) ◽  
Author(s):  
Line C. Gjerde ◽  
Fartein Ask Torvik ◽  
Kristian Amundsen Østby ◽  
Gun Peggy Knudsen ◽  
Nikolai Czajkowski ◽  
...  
Keyword(s):  
Mental Disorders ◽  
Environmental Factors ◽  
Sick Leave ◽  
Twin Studies ◽  
Control Design ◽  
Twin Data ◽  
Epidemiological Research ◽  
Socioeconomic Gradient ◽  
Broad Array ◽  
Medical Benefits

Linking national registries with twin data represents an opportunity to produce epidemiological research of<br />high quality. National registries contain information on a broad array of variables, some of which cannot be<br />measured reliably in regular health surveys. By taking kinship into consideration, twin studies have the<br />benefit of being able to identify confounding stemming from genetic or shared environmental sources. In<br />this paper, we use examples from our own interview and questionnaire-based twin studies from the Norwegian<br />Twin Registry (NTR) on mental disorders, alcohol use and socioeconomic status linked to registry<br />data on medical benefits to demonstrate the value. In the first example, we examined to what extent genetic<br />and environmental factors contributed to sick leave and disability pension and the association between these<br />two types of benefits. In the second example, we explored the genetic and environmental relationship<br />between personality disorders and sick leave. In the third example, a co-twin control design was applied to<br />explore whether there is a true protective relationship between moderate alcohol consumption and health.<br />The fourth example shows to what degree anxiety and depression are associated with later sick leave granted<br />for not only mental disorders, but also somatic disorders, adjusted for confounding by genetic and shared<br />environmental factors. In the fifth example, we address the socioeconomic gradient in sick leave, adjusting<br />for non-observed confounders associated with the family in a co-twin control design. Our examples illustrate<br />some of the potentials obtainable by linking national registries with twin data. The efforts that have been<br />made to create the NTR in Norway and the International Network of Twin Studies (INTR) internationally<br />make these types of linkage studies easier to conduct and available to more researchers. As there are still<br />many areas to explore, we encourage epidemiological researchers to make use of this possibility.

Cannabis use in the last year in a US national sample of twin and sibling pairs

2002 ◽  
Vol 32 (3) ◽  
pp. 551-554 ◽  
Author(s):  
K. S. KENDLER ◽  
M. C. NEALE ◽  
L. M. THORNTON ◽  
S. H. AGGEN ◽  
S. E. GILMAN ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Family Environment ◽  
Genetic Factors ◽  
Twin Studies ◽  
National Sample ◽  
Population Based ◽  
Cannabis Use ◽  
Self Report ◽  
Sibling Pairs ◽  
Sibling Resemblance

Background. Three prior population-based twin studies, none of which was nationally representative, suggested that both genetic and familial–environmental factors contribute to family resemblance for lifetime cannabis use. We seek to replicate these results in a US national probability sample of twin and sibling pairs examining only last year cannabis use.Methods. Cannabis use in the last year was assessed by self-report questionnaire. Biometrical twin analyses were performed.Results. Twin and sibling resemblance for last-year cannabis use was substantial, and much higher in monozygotic pairs than in dizygotic and sibling pairs, where levels of resemblance were similar. Modeling suggested that sibling resemblance was due to genetic factors – with a heritability of at least 60% – and probably family environmental factors. No evidence was found that cannabis use was influenced by a special twin environment.Conclusions. Consistent with prior studies, use of cannabis is substantially influenced by genetic factors but family–environment is also possibly of importance.

scholarly journals Education, lifestyle and life course differences in level of work incapacity – genes and environment

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
K Seglem ◽  
F Torvik ◽  
E Røysamb ◽  
L C Gjerde ◽  
P Magnus ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Educational Attainment ◽  
Sickness Absence ◽  
Genetic Factors ◽  
Twin Studies ◽  
Registry Data ◽  
Equation Modeling ◽  
Lifestyle Behaviors ◽  
Genes And Environment ◽  
Working Age

Abstract Background As many countries face an aging workforce, it is becoming ever more relevant to understand the underlying causes of work incapacity across the entire working age. Previous twin studies have demonstrated that work incapacity is influenced by genetic as well as environmental factors. Furthermore, educational attainment and lifestyle behaviors are relatively stable from early adulthood and are associated with work incapacity. This association may be confounded by unobserved factors - both genetic and environmental. In two separate twin studies, we examine 1) the stability and change in genetic and environmental factors influencing work incapacity from age 18 until retirement, and sex differences in these effects, and 2) the associations and likelihood of causality between educational attainment, lifestyle and sickness absence. Methods study 1: A population-based sample of 28,759 twins were linked to high quality national registry data and followed for up to 23 years. We measured work incapacity as the total proportion of potential workdays lost due to sickness absence, rehabilitation, and disability benefits. study 2: Data from a subsample of 8,806 twins who completed health questionnaires were linked to registry data on sickness absence and educational attainment. Self-reported lifestyle behaviors were smoking, physical activity and BMI (height and weight). Results study 1: Structural equation modeling indicated moderate genetic influences on work incapacity throughout life in both men and women, with a high degree of genetic stability from young to old adulthood. study 2: Preliminary regression analyses indicated that genetic factors largely confound the associations between educational attainment, lifestyle and sickness absence. Conclusions Genetic factors seem to be a major issue in understanding causes of work incapacity. Largely the same genetic factors influence individual differences in work incapacity throughout working age.

Sign in / Sign up

Export Citation Format

Share Document