Citation

Reynolds CA, Turner A, Gatz M, Pedersen NL. Twin Res. Hum. Genet. 2005; 8(2): 113-119.

Affiliation

Department of Psychology, University of California at Riverside, Riverside, California 92521, United States of America. chandr.reynolds@ucr.edu

Copyright

(Copyright © 2005, Australian Academic Press)

DOI

10.1375/1832427053738791

PMID

15901474

Abstract

Twins are sometimes used as proxy informants but little is known about reliability and validity of the information thus obtained. The present study asks: (1) to what extent do twin pairs agree with each other on comparative ratings of health, psychosocial traits, and environmental exposures?; and (2) how well do comparative ratings agree with usual self-reported information about the exposures? Using 55 monozygotic (MZ) and 71 dizygotic (DZ) same-sex pairs reared together, percentage agreement was calculated for 44 comparative ratings. Pairs agreed on average about half of the time. Agreement was higher for more discrete exposures, such as smoking, but lower for more subjective variables, such as the degree to which life is experienced as stressful. Signed rank tests were used to contrast comparative ratings to differences in self-reports. Differences between twin partners in their self-report indices, where available, were in the direction suggested by the comparative rating. Comparative ratings appear most accurate for smoking and alcohol use, and less consistent for mental health symptoms and self-rated health.

Language: en