Dr Immanuel Birmelin has devoted more than 25 years to investigating the behaviour of animals in zoos, circuses, and the home. He has extensively studied pet behaviour, and was able to demonstrate through tests that dogs have the ability to reason, and are therefore not weak-willed servants of man, but thinking, sensitive fellow creatures. The dog owner who embraces this fact will find it considerably easier to teach his dog many things; the need for intensive drilling is not as great as previously assumed. This was the subject of Immanuel Birmelin's film Dog or cat - which is smarter? which created a sensation in 2003, and was followed up by guest appearances on television talk shows. The author is also active as a scientific advisor for animal film productions, and as an authority on the correct care of animals.