The First ‘Classical’ Twin Study? Analysis of Refractive Error Using Monozygotic and Dizygotic Twins Published in 1922

• Published in: Twin research and human genetics Vol. 8; no. 3; pp. 198 - 200
• Main Authors: Liew, Shiao Hui M., Elsner, Hanno, Spector, Tim D., Hammond, Christopher J.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.06.2005
• Subjects: Diseases; Diseases in Twins - genetics; Diseases in Twins - history; Dizygotic twin (DZ); Eye; Female; Genetic aspects; Heredity, Human; Heritability; History, 20th Century; Humans; Male; Monozygotic twin (MZ); Phenotype; Refractive errors; Refractive Errors - genetics; Refractive Errors - history; Twin studies; Twin Studies as Topic - history; Twins; Twins, Dizygotic - genetics; Twins, Monozygotic - genetics
• ISSN: 1832-4274; 1839-2628
• DOI: 10.1375/twin.8.3.198

The first classical twin studies, recognizing the potential of comparing findings in identical twins, have previously been reported to be those by Siemens and by Merriman, both published in 1924. However, we would like to bring to attention a study performed by Walter Jablonski, 2 years earlier (1922), investigating the contribution of heredity to refraction in human eyes. Jablonski examined the eyes of 52 twin pairs and by comparing the size of within-pair differences between identical and non- identical twins was able to infer the heritability of a trait. Therefore, this is likely to be the first reported classical twin study.