We send invitations via snail mail or email to potential twins who are either identified through the Department of Licensing (DOL) or request an invitation through our website. If a twin is interested, we extend the invitation to the other member of the twin pair as well. Once both twins have consented to participate, we enroll the pair in the Registry. For twins 12 and under, the parent or guardian enrolls both twins. Twins 13 to 17 enroll with permission of a parent or guardian.

Periodically, Twin Registry members are invited to participate in new studies developed by prominent scientists around the world. In any such study, participation is completely voluntary and participants may withdraw at any time. Some of our studies involve in-person visits or telephone interviews, while others are conducted entirely online. This diversity in study design allows us to include twins no matter where they currently live.

The Twin Registry holds events for twins in the Puget Sound area. To read about our outreach events, click here.