Twin Studies Research Papers - Academia.edu (original) (raw)

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- Behavior Genetics, EEG, Twin Studies, Frontal Eeg Asymmetry

This book addresses the motif of literary twinship from the Shakespearean age until today. Twins have all too often been discussed as mere footnotes to the allegedly more nuanced motif of the doppelganger, or as a kind of 'embarrassing' secret of literary history that is said to occur merely in inferior genres like farce or horror fiction. This study, by contrast, makes a case for the complexity of literary twinship across the literary spectrum, and it demonstrates that twinship articulates bodily anxieties, dynastic troubles, and genetic concerns that the classic double trope cannot ac-commodate. While the book does not deliver a complete and unabridged history of literary twin-ship (as such a history would inevitably be one marked by long gaps), it still examines twinship in a diachronic fashion and in different historical periods in order to show how the category of twinship is frequently re-negotiated as part of larger discursive shifts. Some historical periods understand twins mainly as a biological conundrum that threatens to expose the arbitrary laws of dynastic kin-ship, others as an epistemological problem that challenges any attempt to impose clear-cut definitions.
The individual case studies trace the development of the category of twinship over time, demonstrating how the twin was repeatedly (re-)invented as a cultural and pathological type when other discursive areas (including the fields of criminology and eugenics) constituted themselves, and how it served as the battleground for ideological disputes. It is in-midst of these discursive processes that I locate literary twinship, and my goal is not to demonstrate that literature 'mirrors' scientific debates of the day. Not only is it evident that literature frequently prefigured the discussions of modern twin scholarship, it has also been instrumental in facilitating these debates and in contributing to the negotiation of power shifts, for instance by setting the stage for debates regarding kinship systems in the Shakespearean age, by engaging in the Victorian reformulation of the criminal as genetically/pathologically evil, or by contributing to the dystopian quality of cloning discourse in the 20th century.

- by Wieland Schwanebeck
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- Comedy, Shakespeare, Adaptation, Victorian Literature

Contributions from 19th Century scholars to binocular rivalry research are well recognized, however, observations concerning the phenomenon commenced centuries earlier and suggest a rich seam of research that is much less well known. This chapter discusses these early investigations, along with conflicting views and observations thereafter. We also discuss the early application of notions of attention and consciousness to rivalry. Such notions have more recently been the subject of concerted investigation into distinguishing brain activity mediating the rivaling states from that underlying visual stimulation. Observations in the literature that preceded this key principle are discussed. We also trace the rivalry studies that followed and note their relevance to current thinking on the phenomenon.

- by Trung T . Ngo
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- Experimental Psychology, Binocular vision, William James, Attention
- by Alison Cool
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- Genetics, Anthropology, STS (Anthropology), Twin Studies
- by Tim Taylor
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- History, Narrative, Critical Psychology, Discourse

Nelle ricerche contemporanee, i gemelli offrono un punto di vista privilegiato per provare a tracciare una possibile linea di demarcazione tra ciò che dipende dalla "natura" (dal patrimonio genetico) e ciò che è invece prodotto dalle condizioni ambientali e socio-culturali. Ma già nel Medioevo i gemelli avevano attirato l'attenzione di medici e maestri universitari per la possibilità di avvalersene come banco di prova per i propri modelli teorici. Il volume si propone una prima ricognizione dei dibattiti medievali sui gemelli, tenendo conto dell'intersezione tra istanze epistemologiche diverse: mediche, morali, filosofiche e teologiche. I gemelli permettono in effetti ai medievali non solo di ripensare le teorie sulla generazione umana ereditate dal mondo greco-romano, ma anche di valutare le pretese scientifiche di discipline come la fisiognomica e l'astrologia, di indagare il modo in cui la grazia diversifica la natura, e di testare (soprattutto attraverso la teratologia e i casi di gemelli congiunti) una serie di ipotesi sull'irripetibilità delle complessioni, sull'unicità o pluralità delle forme nel composto uma-no e sulla costituzione dell'identità individuale.

- by Gabriella Zuccolin
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- Medieval Philosophy, Medieval Theology, Twin Studies, Medieval Medicine

"Three Identical Strangers" is a documentary film telling a "bizarre" story of American triplets. Wathching this film we may wonder: "Do we live in a “chancy, chancy, chancy world?" The Effect of Celestial Twins (ECT) rejects the idea of such an improbable universe and proposes instead a hypothesis that a new temporal factor (the Theta-factor) plays an important role in shaping our personalities and life-paths.

- by Laura Baker
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- Personality Psychology, Personality, Behavior Genetics, Twin Studies

Il presente lavoro intende far emergere le peculiarità del processo di soggettivazione di un gemello rispetto ad un nato singolo. Al fine di ciò, è stata posta la vita prenatale della coppia come oggetto d’indagine, in quanto ritenuta la... more

Brusewitz, G., Parker, A., Luke, D., & Puhle, A. (2015, July). An experimental study of physiological connectedness among twins in relation to attachment. Paper presented at the combined 58th Annual Convention of the Parapsychological... more

- by David Luke
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- Psychology, Parapsychology, Attachment Theory, Twin Studies

Brusewitz, G., Parker, A., Luke, D., Puhle, A., & Friday, R. (2016, June). A new extended exploratory study of physiological connectedness among twins in relation to attachment. Paper presented at the combined 59th Annual Convention of the Parapsychological Association and 35th Annual Conference of Society for Scientific Exploration, Boulder, Colorado, 19th-24th June.

- by David Luke and +1
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- Parapsychology, Psychophysiology, Attachment Theory, Adult attachment

The principal aim of this study is to determine the relative contribution of genetic and environmental factors to the constructs of the Revised Reinforcement Sensitivity Theory. The sample comprised 184 twins of both sexes, aged 18 to 41 (96 monozygotic and 88 dizygotic). Reinforcement Sensitivity Questionnaire (29 items), measuring 5 rRST constructs (BIS, BAS, Fight, Flight, and Freezing), was applied in the study. Heritability of five personality dimensions was examined using full univariate ACE twin models. All models (except for Freezing) have satisfactory fit. Non-shared environment has largest contributions to all dimensions’ variances (55% to 73%). Additive genetic contributions are the largest for Freezing (32%) and BAS (20%), while shared environment contributes most substantially to Flight (25%), Fight (21%) and BAS (20%). The results particularly point to crucial role of environmental factors in shaping the reactions to both signals of reward and signals of punishment.

- by Veronique Dasen
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- Astrology, Twin Studies, Birth

Az ikrek száma mind világszerte, mint hazánkban növekedésnek indult. Míg az összes születésszám jellemzően csökkenő jelleget mutatott az elmúlt évtizedekben, az 1990-es évek végétől az ikerszületések száma emelkedni kezdett. Egyre többször találkozhatunk tehát ikerpárokkal. Ilyen találkozások alkalmával szinte mindenki véleményt nyilvánít, legyen az pozitív vagy negatív. De mit gondolnak maguk az érintettek? Mennyire élvezik az iker-helyzetüket, és vajon milyen problémákkal kell megküzdeniük az ikres szülőknek? Tanulmányunkban az ikerkutatások áttekintése után a 2012-es, ikres szülőkkel készült felvételünk eredményeiről számolunk be egy leíró elemzés keretében, különös tekintettel a szülők saját szavaival megfogalmazott beszámolóira. ABSTRACT The number of twins has begun to increase both in Hungary and all over the world. Although all the numbers of births were typically decreasing during the last decades, since the end of the 1990s, the number of twin births began to increase. We come across twins more and more often. In case of these encounters almost everyone expresses an opinion, positive or negative. But what do the affected people say themselves? Do they enjoy being twins? What kind of problems do parents with twins have to tackle? In our study, after the review of the twin research, we shall present you the results of our reports of 2012 concerning parents with twins in the frame of a descriptive analysis, with special regard to the reports of the parents formulated by their own words.

- by Zsofia Drjenovszky
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- Twin Studies, Twins, Twins studies (PhD), Twinning

Twins appear remarkably often in the earliest examples of Victorian detective fiction. However, they do not merely stand for simple ‘cop-outs’ in the sense of unlikely final-act resolutions. As a reading of C.W. Adams’s recently rediscovered "Notting Hill Mystery" (1865) illustrates, twins always run the risk of exceeding the grasp of the detective’s (as well as contemporary science’s) comprehension and were thus integral as heuristic aids in the formation of the genre.

- by Daniel Nelson Jones
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- Genetics, Neuroscience, Cognitive Psychology, Cognitive Science
- by Bernard Le Foll
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- Psychology, Depression, Bias, Twin Studies

This paper engages a common view that pervades theoretical interpretations of twins—the notion that twinship is a result of each twin being a failed self which results in a singular entity or a we-self. Put differently, there is a widespread view that the self-other distinction is absent or lost in twinship. I demonstrate this by examining twin studies mainly from the psychoanalytic tradition. From this, we see that this assumption is so widespread that twins are considered to lack individuality due to the alleged pathologically interdependent nature of their twinship. Hence many hold that twins form a unit identity which enables them to operate as one person. Yet, twin's first-person accounts do not corroborate this view. Rather, they see their twinship as a joint enterprise which includes a sense of self and other. Yet, rather than acknowledging this, the literature reduces twinship to a form of psychopathology. I argue that this is a consequence of the assumption that twinship can be fundamentally understood as a result of each twin being a failed self which results in a we-self. In order to dismiss this claim, I turn to the notion of the minimal self, which situates the self in the mineness of one's first person experience. As a result, it will become evident that there is a self-other distinction in twin relations and their highly entwined but separate identities could not arise without this being so. I end by recommending, that these researchers broaden their understanding of selfhood by recognising the fundamental and basic experiential structures of the self. In turn, this will allow them to work from the position that twinship, rather than been the consequence of two failed selves, manifests due to the reciprocal engagement of two minimal selves or subjects of experience.

- by J.W. Hoctor
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- Psychoanalysis, Self and Identity, Phenomenology, Twin Studies

This essay shows how the Tudor biblical drama Jacob and Esau (1568) systematically and strategically stages kinship connections in such a way as to justify Jacob's usurpation of the birthright blessing. It then considers one kinship connection in particular: namely, the complicated bond between twins. The essay reveals how the stageplay leverages twinship to raise pressing questions about the apportionment of wealth, affection, and opportunity among siblings, anticipating by several decades the heated debates about primogeniture that erupt in the 1630s. However, the interlude ultimately sounds a pious note, moving beyond the problems of worldly families to emphasize the blessed state of God's family, formed not by biological kinship ties but by arbitrary acts of divine adoption.

- by Lynn Langmade
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- American Literature, Short story (Literature), Twin Studies, Edgar Allan Poe

The study examined the etiology of individual differences in early drawing and of its longitudinal association with school mathematics. Participants (N = 14,760), members of the Twins Early Development Study, were assessed on their ability to draw a human figure, including number of features, symmetry, and proportionality. Human figure drawing was moderately stable across 6 months (average r = .40). Individual differences in drawing at age 4½ were influenced by genetic (.21), shared environmental (.30), and nonshared environmental (.49) factors. Drawing was related to later (age 12) mathematical ability (average r = .24). This association was explained by genetic and shared environmental factors that also influenced general intelligence. Some genetic factors, unrelated to intelligence, also contributed to individual differences in drawing.

- by Victoria Garfield
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- Genetics, Twin Studies, Behavioural Genetics

Despite an extensive literature, the "g" construct remains a point of debate. Different models explaining the observed relationships among cognitive tests make distinct assumptions about the role of g in relation to those tests and specific cognitive domains. Surprisingly, these different models and their corresponding assumptions are rarely tested against one another. In addition to the comparison of distinct models, a multivariate application of the twin design offers a unique opportunity to test whether there is support for g as a latent construct with its own genetic and environmental influences, or whether the relationships among cognitive tests are instead driven by independent genetic and environmental factors. Here we tested multiple distinct models of the relationships among cognitive tests utilizing data from the Vietnam Era Twin Study of Aging (VETSA), a study of middle-aged male twins. Results indicated that a hierarchical (higher-order) model with a latent g p...

- by Carol Franz
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- Psychology, Cognitive Science, Intelligence, Cognition

Entre 1750 et 1756, un couple du petit village de Mortroux, entre Maastricht et Liège, a eu successivement cinq paires de jumeaux et des triplés. Il s'agit certainement d'un cas unique dans l'histoire mondiale de la médecine.

- by Régis de la Haye
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- Twin Studies, Histoire de la médecine

This paper reflects on the media and popular culture fervour over gay etiology studies in the US in 1990s. This paper provides a brief overview of the major genetic studies conducted over the last 200 years and includes a review of the underlying essentialist hypotheses that predate the discovery of genes. Following this overview the article analyzes these scientific studies within the economic, political, and cultural context in which they undertaken, paying particular attention to the rights-based claims that were being articulated by gay and lesbian activists at the time.

- by Ryan Conrad
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- Genetics, Queer Studies, Philosophy of Science, History of Science
- by Caroline Edmonds
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- Psychology, Twin Studies

Binocular rivalry (BR) is an intriguing phenomenon that occurs when two different images are presented, one to each eye, resulting in alternation or rivalry between the percepts. The phenomenon has been studied for nearly 200 years, with renewed and intensive investigation over recent decades. The rate of perceptual switching has long been known to vary widely between individuals but to be relatively stable within individuals. A recent twin study demonstrated that individual variation in BR rate is under substantial genetic control, a finding that also represented the first report, using a large study, of genetic contribution for any post-retinal visual processing phenomenon. The twin study had been prompted by earlier work showing BR rate was slow in the heritable psychiatric condition, bipolar disorder (BD). Together, these studies suggested that slow BR may represent an endophenotype for BD, and heralded the advent of modern clinical and genetic studies of rivalry. This new focus has coincided with rapid advances in 3D display technology, but despite such progress, specific development of technology for rivalry research has been lacking. This review therefore compares different display methods for BR research across several factors, including viewing parameters, image quality, equipment cost, compatibility with other investigative methods, subject group, and sample size, with a focus on requirements specific to large-scale clinical and genetic studies. It is intended to be a resource for investigators new to BR research, such as clinicians and geneticists, and to stimulate the development of 3D display technology for advancing interdisciplinary studies of rivalry.

- by Trung T . Ngo
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- Human Factors, Twin Studies, Binocular Rivalry, Genetic studies
- by Kai Hiraishi
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- Evolutionary Psychology, Twin Studies, Second to Forth Digit Ratio
- by Sharon Dawe
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- Neuroscience, Psychology, Clinical Psychology, Cognitive Science
- by Ureczky Eszter
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- Space and Place, Narcissism (Psychology), Twin Studies, Homosexuality
- by Laura Baker and +2
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- Psychology, Behavior Genetics, Twin Studies

Unlike any other family relationship, twins are culturally understood as uncommon, special, and unique, while simultaneously in need of intervention to become separate, healthy individuals. Consequently, twins occupy a liminal cultural space where the spectacle of their relationship is praised and the intimacy of their relationship is often denigrated. To explore how individual twins navigate this double-bind, we adopted a cultural approach to examine the communicative constitution of intimacy in twin relation- ships (or twinships). Thirty-one twins participated in individual interviews about their relationship with their co-twin. Participant interviews indicated that twins make sense of their intimacy on a continuum of high and low levels of twintimacy, or intimacy of twin relationships characterized by individual and cultural constructions of twinships as extraordinary. Our findings revealed that twintimacy is both similar to and different from intimacy in singleton relationships. We discuss theoretical and practical implications of these results.

- by Julia M. and +1
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- Interpersonal Communication, Intimacy, Twin Studies, Twins
- by Joanna Sikora
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- Sociology, Education, Sociology of Education, Social Sciences

"Background: The aim of this study was to investigate the relationship between congeni-tal hypothyroidism and several variables using two different adjustment methods.
Methods: This matched case-control study was conducted in Hamadan Province, the west of Iran, in 2012 enrolling neonates born between 2005 and 2011 and covered by screening program for congenital hypothyroidism. The neonates with TSH titer more than 10 mU/l or T4 titer less than 6.4 μg/dl were considered as cases. Each case was individually matched for birth place and year with four neonates with normal TSH and T4 titers as controls. The data were analyzed using two different approaches including pro-pensity score and multiple conditional logistic regression model.
Results: Of 1313 enrolled neonates, 277 (159 girls) were cases and 1036 (531 girls) were controls. The most important prognostic factors which had significant effect on congenital hypothyroidism included twin, birth season, maturity, jaundice at birth, birth weight, age at pregnancy, maternal anemia and goiter, gestational age, delivery type, father’s education and smoking status, and consanguinity. The associations reported by logistic regression were stronger that of than propensity score analysis in most items, although the differences were not statistically significant.
Conclusions: We addressed the effect of numerous potential risk factors on congenital hypothyroiditis and the impact of these factors on the disease occurrence. However, future prospective studies are needed to test these findings and hypothesis and to inves-tigate the true effect of these potential risk factors on congenital hypothyroiditis."

- by Scott Shane
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- Entrepreneurship, Management, Genetics, Sex

Recent sociological and cultural analysis points to one overarching conception of twinship that pervades our social imaginary. In the West, we seem to imagine twins as occupying a single subject position. Put differently, many conceive twinship as constituting a supraindividual or we-self. Hence, I explore how this so-called we-self arises by utilising the narrative account of self. I turn to twins' accounts of autobiographical memory, which demonstrates that they construct a we-narrative to give consistency to their wealth of shared experiences. However, I argue that twins do not construct their we-narrative for themselves. Rather, they develop the narrative so that others can comprehend them. To understand this, it is necessary to clarify the phenomenology of doubles. That is, what occurs when a singleton has experience of identical looking twins. I argue that a phenomenological experience of twins creates ontological uncertainty in one's practical experience, because they cannot easily assimilate twins into a normative model of selfhood. This, in turn, removes the difference between each twin, and thus, they are reduced to a singular entity. This then becomes the basis of the narratives that singletons tell about twins. The process then becomes circular, as twins— in order to make themselves comprehensible to others—construct a we-narrative, which only serves to reinforce the notion of the we-self. Thus, it becomes evident that twins cannot be characterised as a supra-individual or we-self, rather, for a twin, twinship is a joint enterprise which includes a sense of self and other. Consequently, I argue that the phenomenology of doubles points to a limitation of narrative understanding. More precisely, placing others within unifying narratives runs the risk of what Levinas calls totalisation. Put crudely, narratives fail to respect the otherness or alterity of the other as it removes their differences to make them coherent and comprehensible.

- by J.W. Hoctor
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- Self and Identity, Phenomenology, Émmanuel Lévinas, Narrative and Identity
- by Laura Baker
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- ADHD (Psychology), Behavior Genetics, Twin Studies, Oppositional Defiant Disorder
- by Laura Baker
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- Decision Making, Behavior Genetics, Twin Studies, Iowa Gambling Task
- by Anne Glowinski
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- Genetics, Epidemiology, Genetic Epidemiology, Mental Health
- by Juko Ando
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- Genetics, Psychology, Cognitive Science, Personality Psychology

This paper will describe the background for this study of identical twins' talk about their lives, by a brief address to psychological and cultural representations of twins. I will suggest that twins are different in the way they speak about themselves, compared to what is shown in the contexts where twins are most represented, particularly the psychological literature and their representations in cultural texts. Both representations reinforce conventional stereotypes about twins, thereby serving as 'misrepresentations' of twins. The paper will then move on to role of life stories in the process of conducting this study, and the themes, often emerging in narrative forms, that came out of the study, centred on couples, identities, and being misunderstood. The paper will conclude by showing how twins' representations of themselves and their relationships work continuously to undermine dominant representations of 'individual subjects', both directly, by posing twins against 'individuals', and less directly, by articulating themes around 'similarity' and 'the couple'. Finally the paper will explore how a narrative analysis could have been applied to the life stories I used in this study.

- by Dr Mvikeli Ncube
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- Twin Studies
- by Alison Cool
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- Anthropology, Medical Anthropology, Twin Studies, Twins
- by Laura Baker
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- Psychophysiology, Behavior Genetics, Twin Studies, Sympathetic Nervous System
- by Michael Neale
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- Psychology, Anxiety Disorders, Family studies, Personality Assessment
- by Laura Thornton
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- Psychology, Sex and Gender, Eating Disorders, Sex Hormones
- by Eric Lacourse
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- Genetics, Psychology, Developmental Psychology, Aggression (Psychology)
- by Ex Snc
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- Genetics, Psychology, Cognitive Science, Psychiatry