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Temporary anxiety is a healthy response to stress; however, continuous anxiety can threaten an individual’s day-to-day living by eliciting negative responses. In the study, monozygotic 84 (MZ) and 153 dizygotic (DZ) adolescent twins pairs, ages 15 to 20 years, participated in anxiety-provoking tasks and subjective experiences of anxiety were measured using subjective units of distress (SUDS). The twin participants were recruited through the Mid-Atlantic Twin Registry (MATR) at Virginia Commonwealth University. The twins participated in a carbon dioxide (CO2) breathing task and a trier social stress task (TSST). The study aims were to evaluate the relationship between anxiety-provoking tasks and subjective experiences of anxiety in MZ and DZ adolescent twins and to compare SUDS ratings in the CO2 task to SUDS ratings in the TSST to determine which task produces greater anxiety. The data was analyzed using correlational models. MZ twins reported more similar SUDS in both the CO2 task and trier task than the DZ twins, however, not at significant values. The mean SUDS ratings for MZ twins and DZ twins were higher in the trier task than the CO2 task, suggesting that the trier task was a better inducer of anxiety than the CO2 task. The goal of the research was to characterize etiological pathways involved in the development of internalizing disorders and to set the stage for advancement of effective intervention and prevention programs, specifically by determining the relationship between SUDS ratings and anxiety-provoking tasks in MZ and DZ twins. Further study is needed to evaluate the heritability of anxiety response.

Publication Date


Subject Major(s)



anxiety, twin study, SUDS


Mental Disorders

Current Academic Year


Faculty Advisor/Mentor

Jennifer Cecilione

Faculty Advisor/Mentor

Dr. Roxann Roberson-Nay


© The Author(s)

Subjective Measures of MZ and DZ Twins during Anxiety-Provoking Tasks