Perceptions of Alikeness and Attitudes toward Being a Twin: Comparison of Identical and Fraternal Twin Pairs

Abstract

A 10-item yes-no questionnaire designed to gather data on similarities between twins in various areas of interest and activity was administered to 63 pairs of like-sexed identical twins and 54 pairs of like-sexed fraternal twins. One open-ended question tapped attitudes toward being a twin. On 8 of the 10 objective questions, the identical twins showed significantly greater similarity than the fraternal twins. An analysis of the attitudes expressed on the open-ended question classified as predominantly positive, negative, or ambivalent indicated that zygosity does not make a difference in attitudes toward being a twin. A larger, but statistically non-significant amount of intrapair disagreement in the fraternal group, contrasted with that for the identicals.

References

Cederlof

Friberg

Jonsson

Kaij

Studies on similarity diagnoses in twins with the aid of mailed questionnaires. Acta Genetics, 1961, 11, 338–362.

Jones

H. E.

Perceived differences among twins. Eugenics Quarterly, 1955, 5, 98–102.

Scarr

Environmental bias in twin studies. In Vandenberg

S. G.

(Ed.), Progress in human behavior genetics. Baltimore: Johns Hopkins Press, 1968. Pp. 205–213.

Smith

R. T.

A comparison of socioenvironmental factors in monozygotic and dizygotic twins, testing an assumption. In Vandenberg

S. G.

(Ed.), Methods and goals in human behavior genetics. New York: Academic Press., Pp. 45–62.

Wilson

R. S.

Twins: Early mental development. Science, 1972, 175, 914–917.

World Health Organization. The use of twins in epidemiological studies. Report of the WHO meeting of Investigators on Methodology of Twin Studies. Acta Geneticae Medicae et Gemellologiae, 1966, 15, 109–128.