Melanie Joy is a psychologist who has spent her career studying the psychology of meat eating, which she calls Carnism. This presentation, about an hour long, is the best analysis of why humans justify the slaughter of animals and consumption of animal body parts. Dr. Joy ends on an optimistic note. Americans are very slowly becoming aware of the animal cruelty that precedes their meat eating behavior. Understanding the root causes of Carnism will help us all become better humans. I urge you to watch this presentation that was given recently at Dr. John McDougall's Advanced Study Weekend.