This volume surveys the way that understanding of the minds of animals and ideas about the relationship between animal and human behaviour developed from around 1870 to 1930. In describing the research and theories which contributed to these developments, this book looks at the people who undertook such studies and the reasons why they did so. Its main purpose is to examine the different ways in which the outcome of this work affected their ideas about the human mind and exerted such a formative influence on psychology in general. This book will be used by first and second year undergraduates studying psychology, and will also appeal to students of the history of science and philosophy. In addition, the lucid, non-technical style of this book will provide an excellent introduction to the general reader who would like to know more about this interesting subject.