A quick overview of an excellent book by the same name -- a description of the career of Harry Harlow and his studies of the science of affection, with special attention to the conflict between Harlow and the then-prevailing view of the subject. Whether you love Harlow or hate him, the animal studies that he and his students conducted resulted in dramatic changes in science's views of affection and the life-long impacts of children's home environments. It's a good example of paradigm shifts in science, and of how (to use Harlow's expression) sometimes science has to catch up with common sense. Listen to this episode, then go give your mom a big hug.