As a behavioral biologist that studies and works with dogs I found issues with the research this book was based on. Looking up video material, I found certain things that made me questions findings, the fact that the researchers involved didn't notice or realize seriously made me questions how much they know and understand about dogs. I wished they had involved some of the big names in the field of dog behavior and research in this, because the fact that they don't ask 'why' a dog may do things they see makes this research semi useless.Why does a dog prefer treats over human praise? Maybe because there's an issue between owner and dog, the way owner praises or acts when dog approaches causes dog to opt for the food. In the same way dogs with food preference were apparently less loyal and attentive towards their owners, but this is caused by the same issue. Dog doesn't like to be handled by owner/humans due to passed experiences.