Chris Christy
— (segments "Twin Reflections" and "Teenage Twins") (archive footage)
Tim Christy
— (segments "Twin Reflections" and "Teenage Twins") (archive footage)
Sean O'Brien
— (segment "Identical Twins") (archive footage)
Tim O'Brien
— (segment "Identical Twins") (archive footage)
Dave Karlstadt
— (segment "Fraternal Twins") (archive footage)
Paul Karlstadt
— (segment "Fraternal Twins") (archive footage)