Ray Blanchard
В роли: Self - PH.D Professor University of Toronto of Psychiatry

Tony Bogaert
В роли: Self - Professor of Health and Science Brock University

David Burns
В роли: Narrator

Andrea Camperio Ciani
В роли: Self - Professor Padova University

Dean Hamer
В роли: Self - Scientist Emeritus National Institues of Health

Kevin Hsu
В роли: Self - Graduate Student Northwestern University

Jean-Baptiste Leca
В роли: Self - Post Doctorate Fellow / Lecturer PH.D University of Lethridge

Richard Lippa
В роли: Self - Professor of Psychology California State University (как Dr. Richard Lippa)

Anne Perkins
В роли: Self - Professor of Anthrozoology Carroll College (как Dr. Anne Perkins)

Mike Sage
В роли: Self (как Bryce Michael Sage)

Francisco J. Sanchez
В роли: Self - Assistant Professor PH.D University of Wisconsin

Maggie Smith
В роли: Self - Undergrad Research Assistant Northwestern University

Eric Vilain
В роли: Self - M.D. PH.D Director of Health UCLA Institute

Paul L. Vosey
В роли: Self - Professor University of Lethridge