Monozygotic And Genetics

2014 Words5 Pages
Keywords: twins, monozygotic, dizygotic, nature, nurture, heritability, Enneagram Diagram, cross-sectional study Introduction For centuries, twin studies have remained a resource for behavioral geneticists to explain the effects of nature and nurture on behavioral traits. Not only do genetics play a critical role in behavioral development, but the environment in which they are surrounded is also crucial to such development. Whether examining twins reared apart or together, twin studies have made significant advancements in separating the effects of nature and nurture on resulting behaviors (Bouchard, 1990). From IQ to personality type to the effects of aging and eating, twins have been analyzed and various results have emerged. From these results, conclusions have been made as to what really plays a larger role in human twin development – genetics or surroundings. However, for one to fully understand the uniqueness that twins present, it is fundamental to know the diversity and complexity that exists among them. What are Twins? Unlike the typical human, twins exist in two forms: monozygotic (MZ) and dizygotic (DZ). Monozygotic, or identical twins, are the product of the separation of one fertilized egg and are consequently genetically identical. Whereas dizygotic, or fraternal twins, are the product of two separately fertilized eggs, sharing 50% of their genes like any pair of siblings (Powlegde, 1993). Because twins come in such variety, not only have studies focused on the behavioral differences between MZ and DZ twins, but also differences that arise due to their upbringing: reared together or apart. Where one may anticipate MZ twins to have identical personalities coinciding with their identical genes, studies have shown other... ... middle of paper ... ...d the need to foster their identical genetic makeup, they tend to surround themselves in similar environments both socially and physically. Then, later in adulthood with increasing life experiences and the onset of disabilities, it may be difficult for twins to generate these paralleled environments and physical appearances between the two shift. However, this remains one possible hypothesis so precise conclusions cannot be made. Thus, in order to show how twins vary through adulthood it is important for studies to continue as they have for twins in premature developmental stages. Heritability of Eating Behavior In recent years, childhood obesity and eating disorders have been controversial topics of debate. Therefore, it may be important to look at the heritability of eating behavior in twins to see where they may lie on this spectrum. In a study by Sung (2010),
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