TITLE OF STUDY: Children of Twins and Their Twin Aunt or Uncle

INVESTIGATOR: Dr. Nancy L. Segal, Professor of Psychology and Director, Twin Studies Center (CSU Fullerton)

PARTICIPANTS NEEDED: Adult children of identical or fraternal twins (18+)

LOCATION: Any English speaking location in United States

PURPOSE OF STUDY: Understand family dynamics in families where twins are identical or fraternal 

METHOD OF INVESTIGATION: Participants will fill out an online questionnaire.

SPONSORING INSTITUTION: California State University, Fullerton

INITIATION DATE: March 2026

COMPLETION DATE: March 2027

FOR MORE INFORMATION OR TO VOLUNTEER TO JOIN THE STUDY, CHECK OUT THIS LINK: https://fullerton.qualtrics.com/jfe/form/SV_38C8mPX3mFWE3NY OR EMAIL DR. NANCY SEGAL: nsegal@fullerton.edu