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Anorexia: Holland (1988)

Twin studies are valuable in research on the genetic origins of clinical behavior because they allow researchers to compare concordance rates between monozygotic (MZ) twins, who share 100% of their genes, and dizygotic (DZ) twins, who share about 50%. If MZ twins show higher concordance for a disorder than DZ twins, this suggests a genetic influence. Twin studies also help estimate heritability, showing the extent to...

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