Have you and your twin brother or sister ever experienced "twin-tuition," where you can communicate mentally, psychically or both without speaking to or touching each other? Have you ever felt pain or joy, and then later found out your twin shared the same feeling at the same time?

Join the conversation about "twin-tuition." Fill out the form below to share your stories and comments, and then tune into "Primetime Nightline: Beyond Belief" on Wednesday, June 29 at 10 p.m./9c.